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| FieroGT/4E introduction (Page 8/13) |
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sleevePAPA
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JUL 11, 12:11 PM
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| quote | Originally posted by fierogt4e:
SleevePAPA;
“Are those specs from the net findings, or have you measured?”
Most are from the net but I am trying to confirm the ones I need.
My stock rods are 5.827”
The wrist pins are all offset to the major thrust side .0315in (.8mm).
stock used head gasket measured at .065”. Over all. Steel parts only .008, .008, .037 The plastic embossing is on both sides of the outer shims.
The stock compression height is 1.305 on this one.
I misunderstood the Cometic site so I took a second look to see how everyone was getting a .051” thick gasket. OK now I see.
The block is ready to hot tank. Then take to work for measuring.
After I decided on a piston I Got a price from the big 3. Then took the part number and put it in a search engine. (Bing) and found them at a $225 savings. nothing on the first page helped. It took some time to find a good price on the rods ($60 off) but a friend hasn't picked up the C-10 parts yet so I'll keep looking till he pays.
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Did you measure the fire ring on the headgasket, or just the edges? Which rods are you going with?
Im still on the fence about turning the crank down that far for a 2.100" Journal, especially since I would like to see 600+ whp from this build.
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fierogt4e
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JUL 11, 10:35 PM
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sleevePAPA
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JUL 12, 02:02 AM
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First, thanks for answering all my questions, I get the feeling you know what your are doing so I hope you don't mind if I ask some more?
I've been following Joseph's build since 2007, mainly from the v6z24.com site. He had a lot of issues with the engine and it only put down low 300's to the wheel. He has been working through the issues but doesn't seem to follow up much anymore. So no real numbers to base my power estimate from. Mars, however, managed to make enough power to put down a 10.56 @ 130mph with a cam only short block. Heads have never been off, but power estimates around the 550 mark.
Mrtohil had a great build going, but IIRC, he passed away before the build was complete and running. Great information produced while he was machining the engine.
Im looking at the Lunati rods, rated for 800hp, and Wiseco pistons right now. Im wondering if you may have some input?
Anyway:
6.125" C2C Rod
2.100" BE, .927 pin
655 grams, but expect lighter to machine for .860" BE width, give or take.
3.903" forged piston
1.050" CH
30cc dish
With this combo, the pistons will be proud of the deck about 0.0105"
DCR of 9.4:1
0.055 Quench
most likely will need to clearance for the valves
Do you forsee any issues with the combination, mainly the pistons proud of the deck?
Thanks! Cant wait to see more updates...
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dobey
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JUL 12, 09:55 AM
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| quote | Originally posted by sleevePAPA:
6.125" C2C Rod
2.100" BE, .927 pin
655 grams, but expect lighter to machine for .860" BE width, give or take.
3.903" forged piston
1.050" CH
30cc dish
With this combo, the pistons will be proud of the deck about 0.0105"
DCR of 9.4:1
0.055 Quench
most likely will need to clearance for the valves
Do you forsee any issues with the combination, mainly the pistons proud of the deck?
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Have you had the deck height measured to be certain about rod length and compression height? How far down is the top ring on that piston? If the top ring is going to get close to the deck, I'd be a little concerned. If top ring is down far enough, cam timing won't result in piston/valve contact, and compressed gasket thickness is ~0.050, I'd think you'd generally be OK though.
I have 6.300 Lunati rods and domed 1.321 CH Wisecos (drop-in replacement for stock bottom engines) for my LSx build. This puts them 0.008" out of the deck on my build. I'm not going for turbo though, and am going for ~11:1 CR.
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sleevePAPA
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JUL 12, 12:03 PM
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| quote | Originally posted by dobey:
Have you had the deck height measured to be certain about rod length and compression height? How far down is the top ring on that piston? If the top ring is going to get close to the deck, I'd be a little concerned. If top ring is down far enough, cam timing won't result in piston/valve contact, and compressed gasket thickness is ~0.050, I'd think you'd generally be OK though.
I have 6.300 Lunati rods and domed 1.321 CH Wisecos (drop-in replacement for stock bottom engines) for my LSx build. This puts them 0.008" out of the deck on my build. I'm not going for turbo though, and am going for ~11:1 CR. |
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Personally, no. I'm only going off what people have found in their own research, which is 8.818" The piston set I'm looking at is wiseco K449x3903, nitrous/turbo pistons. They don't show any figures for top land thickness, but being a turbo/nitrous slug, it probably has a thicker than normal top land. But I will verify eventually.
Compressed gasket thickness has been verified by the OP, at .065" measured at the ring land. I have my engine mocked up for building the hotside and came up with .066" with feeler gauges. I think the cometics are .051", to add to the confusion.
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dobey
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JUL 12, 01:01 PM
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| quote | Originally posted by sleevePAPA:
Personally, no. I'm only going off what people have found in their own research, which is 8.818" The piston set I'm looking at is wiseco K449x3903, nitrous/turbo pistons. They don't show any figures for top land thickness, but being a turbo/nitrous slug, it probably has a thicker than normal top land. But I will verify eventually.
Compressed gasket thickness has been verified by the OP, at .065" measured at the ring land. I have my engine mocked up for building the hotside and came up with .066" with feeler gauges. I think the cometics are .051", to add to the confusion.
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If you can, I'd suggest getting the main bore checked and deck height measured, before getting the rods and pistons. Make sure it's all square. If you need to take material off the decks to square things up, it'll change the dimensions. The stock measurement is usually +/- 0.005 or something like that. So if your block is slightly taller, the pistons will be back in a bit, and if less, they might be out a bit more. If the measurement you're using is correct, and your math is right (I haven't checked it), then 0.010 out of the deck sounds like it would be fine, assuming it doesn't bring the ring up too close to the edge. So I'd say call Wiseco to get the ring land measurement, and get your block measured and checked, and plug in the right numbers to verify it will be good, before clicking on the buy button.
As for the gaskets, Cometic will make you custom gaskets that will compress to any reasonable thickness with any reasonable bore size. Pricing is not much more than their shelf gaskets either.
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sleevePAPA
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JUL 12, 03:42 PM
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| quote | Originally posted by dobey:
If you can, I'd suggest getting the main bore checked and deck height measured, before getting the rods and pistons. Make sure it's all square. If you need to take material off the decks to square things up, it'll change the dimensions. The stock measurement is usually +/- 0.005 or something like that. So if your block is slightly taller, the pistons will be back in a bit, and if less, they might be out a bit more. If the measurement you're using is correct, and your math is right (I haven't checked it), then 0.010 out of the deck sounds like it would be fine, assuming it doesn't bring the ring up too close to the edge. So I'd say call Wiseco to get the ring land measurement, and get your block measured and checked, and plug in the right numbers to verify it will be good, before clicking on the buy button.
As for the gaskets, Cometic will make you custom gaskets that will compress to any reasonable thickness with any reasonable bore size. Pricing is not much more than their shelf gaskets either. |
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OEM MLS gaskets will do just fine. Just so happens that LS engines in general have roughly 0.008-0.009" piston protrusion from what I've been finding. So that's good news. But I will make sure to measure twice before I commit to a combination. Thanks Dobey. Maybe the OP can use some of this data?
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fierogt4e
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JUL 13, 12:45 AM
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SleevePAPA;
I try not to suggest to any body how to build there engine or to assess there build. We're building two very different monsters out of the same engine.
I am talking about what I am building and why. And passing on some info that may help others because hot rodding these little motors is not often done.
I plane to go with “of the self” piston and rods then adjust the stroke to fit. Yes that's backwards. I will be turning the crank down a 1/4” so a slight change in the stroke is no additional expense.
I had my block at work Monday but couldn't get help on the CMM to check all the numbers. Seeing if the cylinders have been moved outward 1.5mm is bothering me also. I may have to do it my self with micrometers but that cant tell me if the cylinders are shifted outward.
The following say what I believe, better than I can say it, about why I'm using the longer rods. Some readers may not know.
Collected from others; (Pros, or not)
Whatever you do don't confuse race engines with street engines. They are two very different critters. Different rod combos are done to find 5-10 hp. Your car will change that much on the street depending if it's 85 or 65 degrees out. Most enthusiasts are limited by budget. Long rod combos are used less, so they generally cost more. If you can find some for a usable price then I'd say go for it. Else stick with the stock length.
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On paper, a longer rod, netting a higher rod/stroke ratio, is supposed to allow you to rev the engine higher at a safe level. This is because less force is being applied as a result of piston thrust (side loading) on the cylinder walls. also, the rod bearings will be taking less of a beating due to "better" attack angles on the power stroke which is likely the biggest worry, in my opinion, when wanting to rev a motor - spinning rod bearings.
Also, from another perspective with the longer rod, its going to dwell at TDC longer which means its going to sit at peak cylinder pressure longer than a short rod. I could see that as a good thing and a bad thing. The good - power loading. It will hold peak cylinder pressure longer which could mean more power. The bad - If you have a hot motor, sitting at peak cylinder pressures is going to create more heat which induces hot spots which in turn increases the likelihood of pre-ignition.
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I guess If I had to choose I'd say use a long rod, especially if the cost difference was slight (which it usually is with today's huge imported parts market). The longer rod will provide better geometry (create less rod angularity) which theoretically will reduce mechanical losses. The longer rod may also help reduce piston weight by making for a more stable piston with a reduced skirt length. The dwell change is very slight, arguably insignificant with a wide array of common rod to stroke ratios. And finally, the ring pack may be squeezed a little at a 1.15" compression height but it is surely a usable distance since C.H.'s of 1.0" are commonly used, even though the wrist pin interferes with the oil ring. There shouldn't be anything too serious to worry about with a long rod.
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Sincerely
George[This message has been edited by fierogt4e (edited 07-13-2016).]
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sleevePAPA
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JUL 13, 01:16 AM
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Thanks for the insight! I've crunched a lot of numbers trying to find a combo that would work well with the stock stroke, as a feel more comfortable with it as it is. So the 6.125" rod seems to be the best match, with a OTS 1.035 slug, and with a 1.050 CH slug. The 1.050 slug seems to be the better option considering the quench distance may fall within .050", and the dish size will yield about a 9.4:1 DCR.
I'll go back to being a spectator now, thanks again! Looking forward to more updates...
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ericjon262
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JUL 13, 10:27 AM
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back to the subject of rocker arms, the 3500 and 3900 use a simlar pedestal mount rocker, and no guideplates are available. I came up with this to replace the pedestal and act as a guide.
12 would be required, as they don't link to the other valves, along with conversion studs. the LX9 rocker bolts thread into the head about 25mm(~1") the longest off the shelf M8x1.25 to 3/8" stud I've come across is about 20mm (~.800"), personally, I want the most thread engagement that I can get with mine, so I'm planning to have ARP make a set for me. there are 5/16" conversion studs available, but there aren't nearly as many rockers available in 5/16", and nothing I really liked was available in 5/16"
Thoughts?
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