TAC Tech => Mechanical => Topic started by: 78T/A4SP on September 19, 2022, 07:48:12 PM
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I have a 1976 400 Engine (#500557) that was recently purchased. It was in a firebird that was an automatic. My car is a manual so I picked up a flywheel from Ames...PQx series. The flywheel can be used on a crank with a 2.50 or 2.75 register. The register on this engine is 2.75 and with the weight removed, it’s a neutral flywheel. Here is the problem. The flywheel is not close enough to the block therefore the starter gear is engaging only about 25%. Contacted Summit Racing, Ames and even Butler Performance. All are stumped. Waiting for a response from RAM as I need to have a flywheel that’s closer. Anybody run into this issue???
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Haven’t heard of that issue but I have an original flywheel laying around I can measure for you if it helps somehow. Just let me know.
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That will help...appreciate it. On the original, is the ring gear mounted flush, closest to the block? Is the original recessed where it mounts to the crank? If so, what is the depth. Thanks.
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Ok here’s what I came up with. The crank flange, if that’s what you want to call it, is about .45” deep and the ring gear is around .28” from being flush with the engine side of the flywheel.
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Thanks for the photos. Definitely is recessed, but the ring gear is offset as well. Just an odd problem. I still have the Pontiac 350 so I will see how the new flywheel fits as it came with a reducer ring to 2.50. Never heard back from RAM regarding this issue. May be buying their flywheel model 1557 I believe. Thanks again.
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No problem, hope it helped. For what it’s worth when I replaced my flywheel this is the one I used. Not sure how it’s balanced compared to a stocker. Seems to be ok but because of another issue I’m having I plan on pulling it to have it compared to the stock balance.
https://www.firebirdcentral.com/Manual_Shift_Flywheel_2_5_Inch_Crank_Hole_p/tra-2880.htm
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Good luck with your issue.
I noticed your flywheel is identical to the one I removed from the 350. I would like to test the fit on the ‘76 400, but the old flywheel inner diameter is only 2.50 compared to 2.75. I plan to remove the new clutch and flywheel and measure everything then test fit the new flywheel to the old engine just to compare starter engagement distance. I will upload pics if can figure out how to do so. Still shocked no one has encountered this problem.
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i may have, i assumed it was my conversion to a hydro set up.........
im running a pqx on my 400, didnt have any issues with the starter but had to shim the bell housing 1/8 of an inch to get the slave on there, but i also converted it to a hydro setup so i blamed it on that. didnt take much to get it on there and im pretty sure mcleod even talks about a bell housing spacer if need be. im cheap so i grabbed some washers. 1 on each bolt got it exactly where i needed it to be.
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I installed the new flywheel on the engine I pulled out. Same results...only engaging about 25% of the flywheel.
Do all starters throw about the same distance? The summit mini starter throws only a 1/2 inch. Does any one have a mini starter to measure the throw?
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Hays flywheels have this issue:
https://forums.maxperformanceinc.com/forums/showthread.php?774649&p=5407930#post5407930
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Thanks, that was a big help. My flywheel is from PRW as well and the ring gear is 1/8 farther back (towards the transmission) than stock, just like the one gentleman described. I could buy another flywheel (looking at the RAM 1557) and hope it’s milled correctly or see what I can do with my current mini starter. Really can’t mill the backside of my starter mount due to the mounting screw stops within the plate. They would end up being if milled out.
Thanks again for the link.
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I lost 6 weeks of time trying to figure out why my current Summit mini starter would not reach the flywheel more than 30% or so. I spoke to Ames where the flywheel was purchased, Summit Racing, Butler Performance, PRW Tech support and this forum. All were stumped. Purchased a second flywheel from RAM...same results. After looking at the aluminum starter block, I noticed the holes that mount to the engine were offset. Looked at other Mini starters for Pontiac and noticed the mount holes were perfectly centered. Ordered a Powermaster starter and installed it. 90% engagement so I had to install the spacer ring that comes with the starter for perfect engagement.
Thanks everyone for all your help. Moving forward!
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Glad you figured it out! Those kinds of problems are pesky critters. I had something similar with over heating on a brand new build, all brand new parts. After replacing everything throughout the coolant system, it was a faulty water pump. These things are definitely frustrating, way to stay at it!