Ok, yes, I got my oil hose yesterday, so I was playing around with it, it ran best exactly as I had it, falling edge, and polarity 1, but it would still loose sync often over 3000 rpm. In the composite log, it shows the 5th notch will read as a double notch. I tried playing with the noise filtering, but the spacing of the bad double notch was similar to the real double notch (very close together), so I couldn't get it to ignore the fake one without ignoring the real one. Also I tried having the crank sensor out little bits, my best result was a reliable 4700, lost sync often above that, if the crank sensor was any farther out, it wouldn't start, and any farther in and it lost sync sooner. So I'm going to keep the wiring in place for the crank sensor in case I decide to figure it out later, but for now I'm going to go straight off the distributor pickup... Which is original, really corroded, and now tests bad just from unplugging the wires to the ICM. Great. Well I ordered a new distributor, always figured I should get one, just never "needed" to haha.
Never mind, some idiot put the cam power wire on the fuel pump line, and the dual wheel option like for the cam before the "crank" (distributor) signal, so it wasn't seeing it, so it never turned the pump on, and nothing happened, I will fix that, but I don't regret ordering a new distributor, I need it haha!
Ok, it's driving pretty well, drove about 20kms today, idled quite a bit, revved quite a bit (check sync), and probably burnt 10 liters of gas (fuel economy is currently not great haha), anyhow on a drive, I hit a maximum of 135 kpa, at a maximum 4900 rpm, at a maximum 80% TPS, with the wastegate flapper disconnected from the actuator (minimum boost possible, looks like the porting I did on the wastegate worked, my blow off valve also works, I hear it when I let off the throttle (depending on what I was doing), although not nearly as loud as pmbrunelle's (recirculating vs not). Haven't lost sync with it running off the actual distributor pickup coil, I have a slight bit of the "getrag rattle" now, it concerned me for several minutes until I recalled it and pressed the clutch haha, but it is perfectly tolerable at it's current level. Currently my intercooler is not working (leak on a fitting, so it's drained and the pump is out), but on that run the MAT was 116* f, with a maximum of 118*, minimum of 111*, over a 4.5 minute drive, coolant/engine fully warmed up. I had filled in the rough calculations for the ECM to calculate hp, and it says I made 175 hp on that run (80%tps, 135 kpa, 4900 rpm).
My afrs are pretty good, there's a very brief lean spike when releasing the throttle fast, other than that tuning is going well, I've played with the idle settings and it's idling and starting pretty well. When using the same AFR target table as pmBrunelle, and starting with the same ve table, it seems to want less fuel at idle and lower rpms, and a little more fuel at mid to higher rpms, it idles at below 20-25 kpa (which seems a little low? I don't know), so maybe it's more efficient at low rpms (roller camshaft, I've done some intake porting, I'm still using the stock IAC passages in the lower intake), and doesn't need as much air or fuel to remain on?, while at mid to high rpms the extra 0.2 liters is breathing more?
Oh yeah, speedometer works great, although sometimes at idle stopped it will read something (vibrations? Noise in the signal? Who knows haha, one thing at a time). I also seem to have a leak in my oil pan gasket, the oil pan's got some oil on it and the seam on the front side of the engine is wet, so yay, I used a new rubber oil pan seal, am I also supposed to load it up with rtv? At first I was worried that it was the rear main seal leaking, but there's nothing on the back of the flywheel, and the oil has seemingly spread from just an area in the bell housing to the front side seam on the oil pan (probably leaking somewhere near the bell housing, and seeping down the seam, thoughts on that? Is oil pan removal hard? Remove engine mount, jack up the engine, support it elsewhere (I've read to rest it on some wood on the balancer?), remove starter, maybe tilt/lower the exhaust a bit?, remove pan. Sound about right? Removing the pan is not something I don't want to do, I want to replace the turbo drain line with my fresh Teflon hose, and I want to relocate the return hole in the oil pan (I'm not happy with the location, it seems to work fine, but I want the return higher in the pan, and I couldn't run it anywhere else with the original hose (to short), now I can run it anywhere with the long new hose haha, so I'll get another oil pan ordered, get it ready (hole drilled, fittings on, hose made), and if my leak gets worse, or I find out why it's leaking, I can fix it immediately and do it right.
Clutch feels good, very very small friction/slip zone compared to my old one, that'll take some getting used to, I've stalled it more today than the last 2 years haha (only a few times, but still). Transmission shifts good, feels good, left to right is a little sloppier than I'd like, but it's more than useable for now, I plan on putting bushings between the select arm and it's support, that part is where the slop is. I have been so concentrated on watching the afr, "feeling"for anything wrong, and watching my rear view for smoke (my exhaust got soaked in oil when that hose melted, the wrap and turbo blanket, so when I first got it started, I idled it until there was some smoke, then let it cool off, then repeat, to burn off the oil without actually catching anything on fire, so that's basically all burnt off now), that I haven't been able to "enjoy" the car haha, I haven't really paid attention to the acceleration or anything, which is probably a good thing because I haven't tried to go full throttle yet, haven't launched it at all, haven't even shifted relatively fast, taking it slow and easy until I'm ready to do otherwise
[This message has been edited by 1985 Fiero GT (edited 05-03-2025).]
Made a short video, this was about 5-7 psi boost, I wasn't paying much attention (I'm sure this car feels much faster right now, but I'm so focused on watching the laptop and making sure everything's good to actually feel it haha, but I definitely think it is significantly faster), the 5 speed feels very natural to me, it feels like the 4 speed with an extra gear on top, clutch is very touchy compared to the old one, but I'll get used to it. I probably drove 80 kms today, with no problems!
[This message has been edited by 1985 Fiero GT (edited 05-04-2025).]
I also discovered that the fill lid thing for my intercooler system has an 1/8 npt tap right on it, so for my intake temp sensor, I'll probably put it right there, that will keep it at the temperature of the intercooler fluid, which should be close to the air temperature, or if it is different, it should be consistently different by a few degrees in all situations, and not heat soak etc.
Drove into work today, pretty tamely, it drove very well overall, I did have to boost it this morning because the battery was dead (I think a headlight didn't go all the way down yesterday, so that's something to look out for in future), I did have one lean spike at a certain rpm/map (3000/150 I think), so I'll have to track that down, but didn't have time to then, so I just drove gently and stayed well below that.
Originally posted by 1985 Fiero GT: My afrs are pretty good, there's a very brief lean spike when releasing the throttle fast,
If you can't feel the spike from the driver's perspective, then it is ok. Transients should be tuned largely by seat-of-the-pants feel, not just by looking at the AFR trace.
It is very difficult to control AFR with a rapidly-changing throttle. Automakers switched to drive-by-wire throttle to (among other reasons) slow down throttle movements, because they weren't able to control the AFR precisely enough during fast throttle movements to meet emissions standards.
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Originally posted by 1985 Fiero GT: When using the same AFR target table as pmBrunelle, and starting with the same ve table, it seems to want less fuel at idle and lower rpms, and a little more fuel at mid to higher rpms, it idles at below 20-25 kpa (which seems a little low? I don't know), so maybe it's more efficient at low rpms (roller camshaft, I've done some intake porting, I'm still using the stock IAC passages in the lower intake), and doesn't need as much air or fuel to remain on?, while at mid to high rpms the extra 0.2 liters is breathing more?
You have a factory camshaft (needs to run well at low speed with good emissions), so 20-25 kPa idle might just be how it is. My car idles at 40 kPa, but it has an aftermarket camshaft more optimized for higher RPMs.
Anyway, adjust the VE (and AFR) table to what your car needs.
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Originally posted by 1985 Fiero GT: Oh yeah, speedometer works great, although sometimes at idle stopped it will read something (vibrations? Noise in the signal? Who knows haha, one thing at a time).
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Originally posted by 1985 Fiero GT: More wiring today (yesterday now I guess), got the reverse switch wired, got the speedometer working (f23 speedo in to ECM on the cam in wires, 4000 ppm speedo out on digital frequency 1, through a 1.2μf capacitor from the tweeter of an old bookshelf speaker to the yellow speedometer high wire going to the dash. Hooking it up directly did not work, speedo is expecting the AC signal from a VR style sensor, not the switched DC of the ECM output, and apparently a simple capacitor in line fixes that).
Also, VR sensor wires should ideally be twisted together to reject noise between the sensor and the conditioning circuit (your ECM in this case).
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Originally posted by 1985 Fiero GT: I also seem to have a leak in my oil pan gasket, the oil pan's got some oil on it and the seam on the front side of the engine is wet, so yay, I used a new rubber oil pan seal, am I also supposed to load it up with rtv?
You might want to put RTV at direction changes (or where multiple parts joint together = hard to seal) with the rubber seal. Also, if the parts are corroded/pitted, RTV may help.
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Originally posted by 1985 Fiero GT: Is oil pan removal hard? Remove engine mount, jack up the engine, support it elsewhere (I've read to rest it on some wood on the balancer?), remove starter, maybe tilt/lower the exhaust a bit?, remove pan. Sound about right?
That's the gist of it. You will likely want to slacken the transmission mounts to avoid twisting them when lifting the engine. Undo the dogbone as well.
[This message has been edited by pmbrunelle (edited 05-05-2025).]
Makes sense, seat of the pants feels pretty good at the moment.
Yup, with more work, it idles at about 32 now, but yeah, I'm just interested in the differences that pop up.
Yeah the noise is between the transmission and ECM, not the ECM and speedometer, it hasn't happened in a little while now, and it isn't really an issue, speed is accurately reported when driving, that's what matters. The wires I'm using for the speedo are the ECM cam sensor input, so they are twisted and shielded, the cam sensor is coming in a digital frequency in, for the hall effect cam sensor.
Makes sense, I'll lather it in rtv haha, I did put some where the timing cover meets the pan and block, but I'll do it better this time, oil pan is ordered, I have the pieces for the new hose and everything else needed, so I'll replace that when I get it.
Also in my video I realized that even though the turbo etc. is so far removed from the engine, it still moves with the engine under acceleration, so I'll make sure I have a look at everything to make sure nothing will bind up, my intercooler support is fine, it's a vertical rod hanging the intercooler from the strut tower, that allows it to move forwards and backwards with the turbo/throttle body, the turbo wastegate actuator bracket is resting on the grooved frame rail, so it isn't fixed in place for front/rear movement, but the weight should be mostly supported and not hanging off the y pipe, just sliding forwards/backwards on the frame, I'll probably add a support like with the intercooler though. With the 2 flex pipes (y pipe and downpipe), I didn't expect the turbo to move with the engine, but it does, so I'll make sure that isn't going to cause any problems.
[This message has been edited by 1985 Fiero GT (edited 05-05-2025).]
Well, bad news, although I don't understand it, some Jehovah's witnesses seemed to have leaked into my oil pan, yep, I have a knock. What I don't understand is why, I had one very brief lean spike during normal operation (I had the afr safety on full blast), and I've had no knocking/detonation/pinging, the engines run smooth as a top. I used a mechanics stethoscope, and the noise is louder when touching the oil pan than the heads, so I guess that would rule out a lifter/rocker etc. (and it was still firing on all 6). I replaced all the main and rod bearings measured clearances, they were on the high end of within spec, but they were within spec, I've never lost oil pressure, even now, although it is reading a little lower than my old 2.8 (I changed oil pressure senders, and the 2.8 was basically pegged to full almost the whole time, so I didn't think to much about that, this was 35psi ish at idle (above the red), 55 at 3000+, estimate based on the gauge).
Rock auto has a remanned crankshaft and bearing set for 200 CAD, so I'm going to drop the cradle, take the oil pan off, see what's up, and hopefully it'll just be the crank and bearings, and the rods and block are fine.
What did I do wrong, was it just the slightly bigger tolerances, 5w30 oil (I know pmBrunelle runs thicker oil, maybe there's a reason for that), and as for tuning I don't see how anything could have gone wrong, things have been running super smooth and the afrs have been rich, and if that one tiny slight lean spike I got this morning was enough to attract the Jehovah's witnesses, then that's rather disconcerting.
It doesn't sound like you were pushing the engine hard, seeing as you just started running/driving the car. Also, you didn't report hearing any knock, so I would be surprised about a tuning-related problem. After changing to the distributor trigger and changing settings there, I suppose you verified the ignition timing with a timing lamp?
Maybe there was some dirt/contamination in the oil which made its way into a bearing, ruining it.
This could have been a metal chip left over from inside a cheap turbo, dirt inside the oil hoses (I washed mine with water and then let them dry before use), maybe rocker arm balls that wore. Perhaps just dirt from the shop.
With thicker oil, the bearings have greater load capacity. Racers won't do this because the added drag from thicker oil costs power. Automakers won't do this because the added drag reduces fuel economy.
[This message has been edited by pmbrunelle (edited 05-05-2025).]
Well, bad news, although I don't understand it, some Jehovah's witnesses seemed to have leaked into my oil pan, yep, I have a knock. What I don't understand is why, I had one very brief lean spike during normal operation (I had the afr safety on full blast), and I've had no knocking/detonation/pinging, the engines run smooth as a top. I used a mechanics stethoscope, and the noise is louder when touching the oil pan than the heads, so I guess that would rule out a lifter/rocker etc. (and it was still firing on all 6). I replaced all the main and rod bearings measured clearances, they were on the high end of within spec, but they were within spec, I've never lost oil pressure, even now, although it is reading a little lower than my old 2.8 (I changed oil pressure senders, and the 2.8 was basically pegged to full almost the whole time, so I didn't think to much about that, this was 35psi ish at idle (above the red), 55 at 3000+, estimate based on the gauge).
Rock auto has a remanned crankshaft and bearing set for 200 CAD, so I'm going to drop the cradle, take the oil pan off, see what's up, and hopefully it'll just be the crank and bearings, and the rods and block are fine.
What did I do wrong, was it just the slightly bigger tolerances, 5w30 oil (I know pmBrunelle runs thicker oil, maybe there's a reason for that), and as for tuning I don't see how anything could have gone wrong, things have been running super smooth and the afrs have been rich, and if that one tiny slight lean spike I got this morning was enough to attract the Jehovah's witnesses, then that's rather disconcerting.
I'm sorry mate! You should have opened the door at the first knock and listen. 5W-30 with those good tolerances on the high margin were the culprit. What was the temperature of the coolant when that happened? You have MS so you should have logged the test right?
With thicker oil, the bearings have greater load capacity. Racers won't do this because the added drag from thicker oil costs power. Automakers won't do this because the added drag reduces fuel economy.
Thicker oil also does keep a better ring seal at higher temps compared to thinner oils like 5W-30. I personally use 10W-40, 15W-40, or 20W-50 in all my engines.
It doesn't sound like you were pushing the engine hard, seeing as you just started running/driving the car. Also, you didn't report hearing any knock, so I would be surprised about a tuning-related problem. After changing to the distributor trigger and changing settings there, I suppose you verified the ignition timing with a timing lamp?
Maybe there was some dirt/contamination in the oil which made its way into a bearing, ruining it.
This could have been a metal chip left over from inside a cheap turbo, dirt inside the oil hoses (I washed mine with water and then let them dry before use), maybe rocker arm balls that wore. Perhaps just dirt from the shop.
With thicker oil, the bearings have greater load capacity. Racers won't do this because the added drag from thicker oil costs power. Automakers won't do this because the added drag reduces fuel economy.
Yeah I had just replaced the distributor before that happened, and I checked with the timing light and it was a perfect 10*when megasquirt was requesting 10*, across the rpm range (acceleration retards the timing up to 3*, probably to to the added play of timing chain and distributor gears. I also did the cylinder spark testing thing that cuts a specific cylinder and that lined up with the correct cylinder on the timing light to, so megasquirt even had that right (I know you had it a cylinder off early on), but yeah it was running well, no signs or indications of any problems at all. Must have been contamination.
I'm sorry mate! You should have opened the door at the first knock and listen. 5W-30 with those good tolerances on the high margin were the culprit. What was the temperature of the coolant when that happened? You have MS so you should have logged the test right?
Coolant has never gone above 212, it's still very cool here, and my Rodney lower temp fan switch keeps it cooler still
Coolant has never gone above 212, it's still very cool here, and my Rodney lower temp fan switch keeps it cooler still
Exactly! 212F water temp and then try to translate 5W-30 oil viscosity at that 212F coolant temp. That 5W-30 would be like a 0w-10 at that 200F. That 0W-10 viscosity has no shear withstanding properties. Any sudden spikes (from knock) and that connecting rod bearing is smashed. Now you have a crankshaft speed noise, twice the cam speed and you got a rod knock.
well I took the top end apart this evening, found several things, all related, any one might have caused the rest.
So first thing I found was a collapsed lifter, it was collapsed several mm, and the pushrod was loose. All my rockers look perfect, they're not an issue. Second thing I found was several pushrods were severely worn where the guide is (this one the worst) I removed all the lifters, and found some of them had metal in the oil groove, the amount of metal seemed to correspond with the pushrod wear, although it doesn't appear to be the same metal, (this is the worst one, the same cylinder as the pushrod above) Long shards of metal, and there were little pieces in the oil hole. All the lifters came out of there bores smoothly and without play (even the ones with the metal in that groove), although some/all of the lifters had some side to side play on the part the pushrod sits on, the little piston thing.
I haven't done anything underneath yet, but I did crank it over with no lifters/pushrods, and it does still sound like it's rattling, especially at the end of the second crank:
So that tells me the bottom end is also very very unhappy.
So, any ideas what went wrong? Was it a lower end bearing that went, metal got everywhere, took out at least one lifter with it, and caused a looseness in the pushrod seat of the others bad enough to wear the pushrods on the guide?
Or was it lifters, which wore the pushrods, which took out the bottom end?
Or was it pushrods wore, which caused that metal to take out the lifters and bottom end?
So at the moment I know I need lifters, the pushrods are probably fine, I'll clean up any sharp edges with some sandpaper and maybe open up the guide slots a little bit. With the amount of metal everywhere, and the rattle when cranking, it's probably safe to say the bottom end is dead, so probably the crank and all the lower bearings need to be replaced. I also saw some pitting on the camshaft, not consistent with any of the other damage (probably from when it was sitting?), so theoretically that should be replaced to, I guess the cam bearings wouldn't have liked this metallic adventure either.
So with all that, I don't know, it might be beneficial to find another engine entirely, but who's to say that will be useable either, so I guess I could:
Repair this engine as best as possible,
Get second engine that may also have issues,
Find something remanufactured, I found a remanned 3500 for $1250us, it would just have to be freight delivered somewhere in the States, so that might be tricky.
The 3400 uses fairly standard rocker arms, with their pivots bolted solidly to the cylinder head. A pushrod with spherical ends fits between the lifter and the rocker arm (which each have spherical sockets).
The Chevrolet small-block V8 engine, and the Chevrolet 2.8 V6 use a special design, where the rocker arm pivot is spherical. Alone, a spherical pivot would allow the rocker arm to flop around. To make this design work, guideplates are used to stabilize the pushrods; it is the pushrods which keep the rocker arms aligned.
There is friction/rubbing between the pushrod and the guideplate. On an engine that uses guideplates, the pushrods need a special hardening to prevent wear; not all pushrods have this.
Could you have made a mistake with pushrod selection?
The 3400 uses fairly standard rocker arms, with their pivots bolted solidly to the cylinder head. A pushrod with spherical ends fits between the lifter and the rocker arm (which each have spherical sockets).
The Chevrolet small-block V8 engine, and the Chevrolet 2.8 V6 use a special design, where the rocker arm pivot is spherical. Alone, a spherical pivot would allow the rocker arm to flop around. To make this design work, guideplates are used to stabilize the pushrods; it is the pushrods which keep the rocker arms aligned.
There is friction/rubbing between the pushrod and the guideplate. On an engine that uses guideplates, the pushrods need a special hardening to prevent wear; not all pushrods have this.
Could you have made a mistake with pushrod selection?
I see, yes, I only paid attention to the length, these are from a 3900, same rocker design as the 3400, no guides, so clearly they weren't hardened, and I have no wear on the current guides, just to some of the pushrods.
Originally posted by 1985 Fiero GT: Or was it pushrods wore, which caused that metal to take out the lifters and bottom end?
...sounds like this is what happened.
Probably you could repair your engine, but you would have to strip it down to the bare block (remove all bearings) and then clean all the metal from the oil galleries. Depending on the damage, it might be easier/cheaper to get another engine.
When assembling an engine, there are a number of details that need to be right, so take your time and check everything!
Probably you could repair your engine, but you would have to strip it down to the bare block (remove all bearings) and then clean all the metal from the oil galleries. Depending on the damage, it might be easier/cheaper to get another engine.
When assembling an engine, there are a number of details that need to be right, so take your time and check everything!
Yeah, I understand, and I thought I did haha, I looked on rock auto, and the pushrods I got have the exact same description, same look, color, advertised material, etc. to the same brands pushrods for the 2.8, no advertisement for "hardening", so yeah, not even something I knew to look out for, or something that was advertised. I think the "easiest", "cheapest", and most "safe" option will be to get another junkyard engine, but also get a remanufactured to spec crank and bearings, obviously find better pushrods. What sounds best to do?
If you buy pushrods on Summit Racing, you can filter by "Compatible with Guideplates", "Yes/No". You should also check that the pushrods are guided only by the sides of the guideplate slots. If the pushrod is binding in the bottom of the slot, then that will cause undue wear/friction.
With a new junkyard engine you won't have to worry about stray metal chips in the shortblock. If you're reusing the same cylinder heads I suppose that you would have to remove the valve springs to clean everything properly.
There may also be metal chips in the turbo (because it was fed with contaminated oil), and in the turbo oil lines...
I think that buying a remanufactured crankshaft is premature; the one in the new junkyard engine might be fine. Check it out first. Aftermarket parts quality is so bad nowadays that replacing parts in a preventive manner often causes more problems than it prevents.
The rod bearing of cylinder #4 is obviously bad.
The rocking of the pistons in their bores looks normal. Pistons are slightly smaller than their bores, so some rocking is possible. Piston-to-bore clearance will increase as the engine wears.
If you buy pushrods on Summit Racing, you can filter by "Compatible with Guideplates", "Yes/No". You should also check that the pushrods are guided only by the sides of the guideplate slots. If the pushrod is binding in the bottom of the slot, then that will cause undue wear/friction.
With a new junkyard engine you won't have to worry about stray metal chips in the shortblock. If you're reusing the same cylinder heads I suppose that you would have to remove the valve springs to clean everything properly.
There may also be metal chips in the turbo (because it was fed with contaminated oil), and in the turbo oil lines...
I think that buying a remanufactured crankshaft is premature; the one in the new junkyard engine might be fine. Check it out first. Aftermarket parts quality is so bad nowadays that replacing parts in a preventive manner often causes more problems than it prevents.
The rod bearing of cylinder #4 is obviously bad.
The rocking of the pistons in their bores looks normal. Pistons are slightly smaller than their bores, so some rocking is possible. Piston-to-bore clearance will increase as the engine wears.
Ok, yeah Summit doesn't have the correct size, I'll probably contact the same people Fiero sound got the pushrods from, they also specify for the guide plates. They were not in the bottom of the slot, they were a few mm from the open end.
For metal, yeah, I'll remove both the hoses (the drain is getting replaced anyway) and clean them, also put some oil through the turbo, but hey, if the turbos injured, that's realistically much less of a headache then even changing the oil pan would have been (remember this turbo is a cheap Chinese albeit well known one, if it survived getting pumped up with glitter, then that's a plus in my book haha). For the cylinder heads. They were surprisingly clean, very little metal got up top there (I guess oil dripping back down the pushrods and flowing back through the drain channels carried most of the metal back to the cam area, but I'll thoroughly clean them. The worst metal was in the lifter bores and going into the holes in the lifters, and generally the camshaft area.
So if the pushrods hadn't ground down the crank and all the bearings would probably be fine to be reliable? Even with the tolerances on the high end of within spec? I really don't want to end up having to wait for parts if the next engine is on the high end of spec or worse, and I can't really expect any different from this engine, I doubt I'll get a magic 25,000km shiny new engine, it'll probably be 150-190 unfortunately. Good to know that some small amount of piston rocking is normal. Combustion chambers all looked good, although I'm definitely running well on the rich side of things, they were a little sooty.
Was my theory of keeping the old pistons and rings which would be better under boost and heat than just buying new rings (more wear, more clearance), is that an "acceptable" compromise, or a recipe to going through this all over again? I did find an engine rebuild shop, and requested a quote for an over bore, just to know my options if I decide to do new rings.
------------------ "I am not what you so glibly call to be a civilized man. I have broken with society for reasons which I alone am able to appreciate. I am therefore not subject to it's stupid laws, and I ask you to never allude to them in my presence again."
I invited Lou Dias to trash me in my own thread, he refused. sorry. if he trashes your thread going after me. I tried.
[This message has been edited by ericjon262 (edited 05-07-2025).]
Originally posted by 1985 Fiero GT: Ok, yeah Summit doesn't have the correct size,
There are a shitload of pushrods for Fiero engines... maybe not if you search "by engine".
If you search for pushrods on Summit by dimensions, 5/16" diameter, 5/16" spherical ends at both ends, etc, you'll find many results. They may come in packs of 16 for V8s.
There are a shitload of pushrods for Fiero engines... maybe not if you search "by engine".
If you search for pushrods on Summit by dimensions, 5/16" diameter, 5/16" spherical ends at both ends, etc, you'll find many results. They may come in packs of 16 for V8s.
I searched again, and they do have one in the right size, I was mistaken earlier because it's a "special order" item, my current bad pushrods were 5.88", and they put the rocker tip sweep dead center on the valve, Fiero sound used 5.85", summit has a single 5.85" option, in the 5/16"diameter, and it is heat treated and compatible with guide plates, $11 US a piece.
Originally posted by 1985 Fiero GT: Was my theory of keeping the old pistons and rings which would be better under boost and heat than just buying new rings (more wear, more clearance), is that an "acceptable" compromise, or a recipe to going through this all over again? I did find an engine rebuild shop, and requested a quote for an over bore, just to know my options if I decide to do new rings.
A junkyard build may last a little while, though probably not a decade. This is your call to make!
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Originally posted by 1985 Fiero GT: I searched again, and they do have one in the right size, I was mistaken earlier because it's a "special order" item, my current bad pushrods were 5.88", and they put the rocker tip sweep dead center on the valve, Fiero sound used 5.85", summit has a single 5.85" option, in the 5/16"diameter, and it is heat treated and compatible with guide plates, $11 US a piece.
I didn't know you were running short pushrods like that. Less than 6" is less commonly available.
Would the contact sweep be ok with 6", or would it be too off?
I didn't know you were running short pushrods like that. Less than 6" is less commonly available.
Would the contact sweep be ok with 6", or would it be too off?
Yeah I have the long roller lifters from the 3400, and the straight valves of the 2.8 (the 3400 had the pushrods all at angles which would make them longer), so yeah, pretty short. I honestly don't know what the contact sweep would look like with 6, I don't fully grasp what changes with what for this, also, the valve tips should have that contact pattern worn on them right? As in you'll see where it goes back and forth, the valve doesn't rotate and wear evenly right? This is what my valves look like, the "wear" can't be felt, is just visible.
I guess I don't really know the pattern to well, as I only had about 100 kms with this setup, and 5000 on these heads and rockers in the 2.8, well anyhow they aren't forming any different patterns outside of that, that I can see.
A junkyard build may last a little while, though probably not a decade. This is your call to make!
Ok, right now with how I'm envisioning the future for me, I would want 5 years of cradle in the car operation (25-50,000 kms), obviously if I upgrade components or want to change something and decide to remove the cradle that's different, or small repairs involving the top end or external accessories, or blow it up with to much boost (I'd settle at 200kpa, above that I'd consider the engine to be allowed to blow up haha, so I'd be accepting a shorter than 5 year life if I exceed that), but I would want the engine to last in the car for 5 years. In the meantime the current block looks alright, so I could prepare that over time, over bore it, new pistons (maybe forged or whatever), fresh everything, build it up ready to replace the 5 year refreshed junkyard engine.
[This message has been edited by 1985 Fiero GT (edited 05-08-2025).]
Well, got the cradle out, which was a challenge for sure, but it's surprising easy to manipulate, this time I've jacked it up by the center of the car with some wood, and because I'm on gravel, I laid wood under the jack, and under the cradle, I also have several logs under the cradle acting as both support to keep it off the ground and high enough to get the jack under, and allowing it to "roll" around. Definitely much less optimal than the last time I did this, on a level garage floor indoors, but it's working. I have 2 Jack stands under the wood spring the car as well, and this and the jack are sharing the load at the moment, the jack is solid in and on the ground, Jack stands less solid, but more than good enough. Is it sketchy? yes, will it work? Probably haha. I only need the engine out another foot or so to get it off the cradle, I've left it like that so I can close the car tent and everything won't get rained on, another evening or 2 will have the engine out/off the cradle, then it's a matter of waiting for the next engine and whatever I order for it. So for a few years of use with another 170k km junkyard engine, I don't need to replace pistons or rings, as long as there are no obvious issues with the new engine, but I should get new main and rod bearings (and measure the clearance). I don't need to get new lifters right? Cam bearings will be fine, even if they are slightly leaky and higher tolerance, this engine is priority mains oiling, so that shouldn't matter, crank and rods I'll assume good, oil pump I can reuse from the dead engine (clean out, it was a high volume pump), I'll order a new timing set, from the older 3400 engine (like double the thickness of the new one that got put on the dead engine), new head gaskets (this time I'll get the felpro permatorque plus or whatever, it's apparently a MLS head gasket, my dead engine just got the normal head gaskets), new pushrods, I should probably get new head bolts (these have been used 3 times now, pmBrunelle, what head bolts did you use?), and new gaskets for everything
do you have the JY engine already? cut the oil filter open and look inside? do you see signs of damage? if no, put it in the car and run it.
------------------ "I am not what you so glibly call to be a civilized man. I have broken with society for reasons which I alone am able to appreciate. I am therefore not subject to it's stupid laws, and I ask you to never allude to them in my presence again."
I invited Lou Dias to trash me in my own thread, he refused. sorry. if he trashes your thread going after me. I tried.
I had good used head bolts on hand, but there are some available on Rockauto. I agree that three times is probably enough uses out of a set of head bolts.
Not all head bolt sets have the stud at the end which is needed to attach the engine-to-body ground strap, so you may want to pay attention to that. You can also attach the ground strap elsewhere on the engine if required.
There is also an ARP head stud kit which is sold for the 2.8L V6, if you wanted a more high-end (and reusable) solution, which could be purchased from WOT-Tech or some other vendor. I don't know if this kit is compatible with the ground strap. If it is mechanically compatible, some wirebrushing of the black oxide finish is likely required to ensure electrical conductivity.
quote
Originally posted by 1985 Fiero GT: So for a few years of use with another 170k km junkyard engine
I don't know about a car guy leaving the powertrain in place for a few years without touching it, somehow for me it seems like I'm dropping the cradle every year or two for whatever reason
I had good used head bolts on hand, but there are some available on Rockauto. I agree that three times is probably enough uses out of a set of head bolts.
Not all head bolt sets have the stud at the end which is needed to attach the engine-to-body ground strap, so you may want to pay attention to that. You can also attach the ground strap elsewhere on the engine if required.
There is also an ARP head stud kit which is sold for the 2.8L V6, if you wanted a more high-end (and reusable) solution, which could be purchased from WOT-Tech or some other vendor. I don't know if this kit is compatible with the ground strap. If it is mechanically compatible, some wirebrushing of the black oxide finish is likely required to ensure electrical conductivity.
I don't know about a car guy leaving the powertrain in place for a few years without touching it, somehow for me it seems like I'm dropping the cradle every year or two for whatever reason
Well yes haha, like I said if I choose to install upgrades or whatever, but I don't want to be forced to drop the cradle to do major repairs without significant warning (like this episode, driving fine for 100kms, then boom, dead engine, have to drop the cradle). I will check out the ARP ones.
I wouldn't trust the Comp Cams roller-tipped rocker arms (which I think you have) for long-term reliability.
Have they broken in without problems now? Has the steel gotten hot and become blue?
They have over 5000kms on them with no color change or evident wear, 5000 on the 2.8, 100 on the 3.4. Best picture I have at the moment. Your rocker issues weren't just with the roller tipped ones, you also had issues with the regular ones, and your valve springs were indenting your heads, so I think coil bind was the issue with the rocker arms wearing and breaking.
[This message has been edited by 1985 Fiero GT (edited 05-09-2025).]
No engine updates yet, I've ordered some parts, figuring out others, the Smith Brothers pushrods were a great price so I ordered them, $108 for the set I think.
I got my t top set last weekend, so I'm also prepping for that, it's not in the best of shape, missing a few pieces (for now, I'm trying to get ahold of the seller), but it could be all installed as is right now and still be less leaky than my sunroof has been haha. The weatherstrip has a couple issues, so I'm going to be trying the 82-92 Firebird weatherstrip with the modifications documented on this forum. Glass is in 8/10 condition (for me, maybe I'm less picky than others, I don't know), T roof is 7/10, main weatherstrip 5/10, interior 0/10 because I don't have it yet haha. I'm trying to decide if I start on installing that while waiting on the engine and parts, or sometime else.
