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| Different 3.4l piston/head compatibility (Page 4/7) |
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1985 Fiero GT
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AUG 11, 07:12 PM
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| quote | Originally posted by 82-T/A [At Work]:
Yep... I can be the same way. This is why I got into the watch hobby... it's budget neutral and they're more valuable over time. But man... I forgot how expensive cars are. When my daughter's done with her Fiero, it'll still maybe be a $5,000 car, totally restored. Hahah... |
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Yeah, well I've always imagined engine swaps to be much more expensive, and harder, granted a turbo and new ECM will make this probably as expensive, but the fact that I found a 3400 engine (with only 170,000km) for 500cad removed, that's impressive!
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pmbrunelle
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AUG 12, 07:20 AM
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pmbrunelle
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AUG 12, 06:40 PM
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Why would you do this project with a 3400 rather than a 3500?
More cubes is better, no?
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1985 Fiero GT
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AUG 12, 07:32 PM
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| quote | Originally posted by pmbrunelle:
Why would you do this project with a 3400 rather than a 3500?
More cubes is better, no? |
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Uhm...I found a 3400 for a steal of a price? I wasn't aware that the 3500 was the same style block, there doesn't seem to be as much information available for it.
Also, I'm going to be piggybacking of your build a lot haha, if I go 3500, I'll have to figure out different injectors, maybe a different turbo, etc. a lower boost (then you) 3.4 should have fairly similar requirements to a higher boost water injected 3.2[This message has been edited by 1985 Fiero GT (edited 08-12-2024).]
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82-T/A [At Work]
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AUG 12, 08:38 PM
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| quote | Originally posted by 1985 Fiero GT:
Uhm...I found a 3400 for a steal of a price? I wasn't aware that the 3500 was the same style block, there doesn't seem to be as much information available for it.
Also, I'm going to be piggybacking of your build a lot haha, if I go 3500, I'll have to figure out different injectors, maybe a different turbo, etc. a lower boost (then you) 3.4 should have fairly similar requirements to a higher boost water injected 3.2
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Yeah, there's also a 3900 V6/60, which is the same engine as the 3500... which is effectively the same as the 3400. The 3900 came in the Pontiac G6. There's a version of it that puts out over 240hp with 240+ foot-pounds of torque. There's even a VVT version of it. As a matter of fact, the 3900 still has the hole for a distributor! LOL... but it's plugged with an oil pump drive that basically installs the lower-half of what would otherwise be a distributor.
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pmbrunelle
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AUG 12, 09:17 PM
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To be more precise, I'm talking about the 3500 LX9 for use as a bottom-end donor for use with the Fiero top-end stuff. I think that La Fiera has experience with this; you can ask him if there are any "gotchas" you need to know about.
3500 LZ4 and 3900 LZ9 have very big bores; I don't think these will work with iron heads. Of course, if you use the entire LZx engine, then you have the same power NA as an iron-head engine with some boost... so it is worth considering.
| quote | Originally posted by 1985 Fiero GT:
Also, I'm going to be piggybacking of your build a lot haha, if I go 3500, I'll have to figure out different injectors, maybe a different turbo, etc. a lower boost (then you) 3.4 should have fairly similar requirements to a higher boost water injected 3.2
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I wouldn't necessarily do everything the same a second time around, though I think the Green Giant injectors remain a good choice.
My turbo's internal wastegate initially didn't flow enough without me having to port it (which luckily solved my problem); I would prefer a higher-flowing wastegate solution from the getgo as a lower-risk solution.
The BorgWarner EFR turbo series integrates good internal wastegates with large flapper valves. The EFR also has an integrated BOV. Since (some models) the EFR integrates BOV and wastegate, plumbing (and hence project complexity) is greatly simplified, and you don't have to spend money on those external parts. The EFR compressors have wide operating ranges, so it is hard to screw up with matching a turbo to your engine. I am not a salesperson; they just look nifty (but yeah, speed costs...)!
Also, for project simplicity/cost, you could dispense with electronic boost control and water injection.
| quote | Originally posted by 82-T/A [At Work]:
the best benefits of either engine, so long as you have the correct ECM running it... is Sequential Port Fuel Injection. This makes a HUGE difference in driveability and performance in the lower RPMs. I spent an unreasonable amount of time reading up on it, and trying to determine if it even matters, and with the exception of wide open throttle above ~3,200 rpms, SFI provides dramatically better engine performance... with more lower-to-mid horsepower and better fuel economy.
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I'm not so sure about the difference sequential injection makes. My Fiero runs fine on sequential injection, but I can force it to run batch-fire if I want.
Sometime I should try driving it in batch-fire to see if sequential is all hype; I was thinking of switching the injection scheme back and forth every day for a week, and then seeing if I notice any differences.[This message has been edited by pmbrunelle (edited 08-12-2024).]
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1985 Fiero GT
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AUG 12, 09:44 PM
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So, this engine I'm getting, it's middle of the road on mileage, 170,000 km, and I do not have access to or budget for a machine shop for anything, unless something is very visible wrong with any component (any seals necessary, piston, bore, etc) I'm going to probably leave it mostly as is. I'll probably put in a high volume oil pump, and I'm wondering if I should replace the main and rod bearings, I see on rock auto, some mahl clevite bearing sets I could get, would it be better to just get the normal size, put them on, and call it a day, or leave the old ones?
| quote | Originally posted by pmbrunelle:
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Yeah, I have found a great deal on the 3400, so I think I'll stick with that, I know more that it will work, so I'm aiming at that direction. As for injectors, wastegates, turbos, BOVs, boost control, water injection, and sequential injection, realistically this project is bigger than I should embark on, and I may end up with some less than ideal parts due to budget. I've found some 42lb Mustang injectors on eBay from a well reviewed seller, that's about all I can afford, I'll have to go with microsquirt, instead of megasquirt, I'm thinking it has enough for me to do everything I need, for now, proof of concept, I'm getting a cheap eBay Turbo (once again, supposedly reputable seller), make sure I can get it all plumbed up and it fits, and if that works, great, if it lasts a summer, great, I'll know what to get next time, the layout in my cardboard assisted design proof of concept has me do very little custom routing, 9" straight shot from turbo to throttle body, cut the y pipe and add a single 90*. My cardboard model was a little bigger all around than the real turbo measurements, and I have some space to play yet. The one thing I won't cheap out on is the clutch, as I won't be wanting to have to change that out again, so yeah, $700 for the spec stage 3+ clutch you got I guess, $500 for the microsquirt, and about $1500 for all piping, turbo, sensors, flywheel, bov, 2 gauges, heat shielding, injectors, oil pump, and maybe main/rod bearings. Any suggestions are welcome, but I definitely have limited budget haha.
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pmbrunelle
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AUG 13, 12:05 AM
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I think that the 3400 oil pump is already "high volume", but it is a good idea to take it apart for inspection.
Piston ring gaps can be filed larger; this is free to do.
Bearing replacement is probably a good idea; check clearances after.
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Microsquirt does not support the Fiero's 4-wire stepper motor idle valve.
This add-on allows Microsquirt to control the Fiero idle valve:
https://www.efisource.com/w...iac-stepper-adapter/
Otherwise, you can change the idle valve to something else, such as the Bosch bimetallic idle valve, or a PWM idle valve. Information:
http://www.extraefi.co.uk/pdf/idle_valves.pdf
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I have a set of 30 lb/hr Accel injectors laying around here if you want them. I ran them on my Fiero before I switched to the Green Giants. You may also need a higher-flow fuel pump.
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Maybe an OEM turbo from a junkyard would be a better bet than an ebay turbo?
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I think I understand what kind of turbo placement you're thinking of, sort of beneath the LH decklid grille. The LH decklid spring may present some challenges. The slave cylinder may come close to the turbine; the slave cylinder should be well-protected.
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On a budget-conscious project, I think you can skip the additional gauges in the cabin. Most of the time, when I'm doing tuning, I'm looking at the data (sometimes live, sometimes as datalogs) on the laptop screen, not the gauges in the cabin.
I mentioned a laptop computer; you need one to tune the engine computer. The laptop computer will also facilitate internet research, saving of documents, etc.
I think that you could do this project in stages:
1. Microsquirt + original 2.8 to get the hang of tuning the engine; get it running and driving smoothly.
2. Microsquirt + refreshed 3400 + bigger injectors; tune a slightly bigger but similar NA engine.
3. Microsquirt + refreshed 3400 + bigger injectors + turbo; tuning for the turbo now, with experience from the previous steps.[This message has been edited by pmbrunelle (edited 08-13-2024).]
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1985 Fiero GT
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AUG 13, 05:24 AM
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| quote | Originally posted by pmbrunelle:
I think that the 3400 oil pump is already "high volume", but it is a good idea to take it apart for inspection.
Piston ring gaps can be filed larger; this is free to do.
Bearing replacement is probably a good idea; check clearances after.
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Microsquirt does not support the Fiero's 4-wire stepper motor idle valve.
This add-on allows Microsquirt to control the Fiero idle valve:
https://www.efisource.com/w...iac-stepper-adapter/
Otherwise, you can change the idle valve to something else, such as the Bosch bimetallic idle valve, or a PWM idle valve. Information:
http://www.extraefi.co.uk/pdf/idle_valves.pdf
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I have a set of 30 lb/hr Accel injectors laying around here if you want them. I ran them on my Fiero before I switched to the Green Giants. You may also need a higher-flow fuel pump.
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Maybe an OEM turbo from a junkyard would be a better bet than an ebay turbo?
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I think I understand what kind of turbo placement you're thinking of, sort of beneath the LH decklid grille. The LH decklid spring may present some challenges. The slave cylinder may come close to the turbine; the slave cylinder should be well-protected.
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On a budget-conscious project, I think you can skip the additional gauges in the cabin. Most of the time, when I'm doing tuning, I'm looking at the data (sometimes live, sometimes as datalogs) on the laptop screen, not the gauges in the cabin.
I mentioned a laptop computer; you need one to tune the engine computer. The laptop computer will also facilitate internet research, saving of documents, etc.
I think that you could do this project in stages:
1. Microsquirt + original 2.8 to get the hang of tuning the engine; get it running and driving smoothly.
2. Microsquirt + refreshed 3400 + bigger injectors; tune a slightly bigger but similar NA engine.
3. Microsquirt + refreshed 3400 + bigger injectors + turbo; tuning for the turbo now, with experience from the previous steps.
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Ok, explain the checking clearances thing?
I'm aware of that, looking for a suitable PWM IAC valve, the PDF didn't load for me for some reason.
What kind of duty cycle were the accel 30lb injectors running?
Trouble is I have no junkyards around me, closest is like 3 hours away, where I'm picking the engine up from, while I'm there, I'll have a look around, see if I see any turbos haha.
Yeah, the slave will be fairly close, if not protruding between the 2 halves a little bit, I have a few inches between it and the decklid spring (which is more to the side) to get it fine tuned.
For gauges, the wideband o2 sensor I'm looking at packages the "converter" in a gauge, gives ECM output, and a gauge to read, one other cheap turbo boost gauge for the fun of it.
I have a laptop, and yeah, stages is a good idea, much of the time I'll have to work on this will likely be over the winter, so yeah, no real tuning other than getting it to startup and idle haha until the spring.
I might be able to get a new ECM and run that for a little while on the 2.8 before winter, I'll have to see.[This message has been edited by 1985 Fiero GT (edited 08-13-2024).]
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82-T/A [At Work]
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AUG 13, 07:16 AM
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| quote | Originally posted by pmbrunelle:
I'm not so sure about the difference sequential injection makes. My Fiero runs fine on sequential injection, but I can force it to run batch-fire if I want.
Sometime I should try driving it in batch-fire to see if sequential is all hype; I was thinking of switching the injection scheme back and forth every day for a week, and then seeing if I notice any differences.
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What system are you running in order to get SFI? You're not using the Microsquirt are you? I thought that didn't support SFI?
My understanding is that throttle response and around-town driving is greatly improved by SFI over MPFI. I've driven both, just not in the same car, so it's speculative.
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