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Discussion Starter · #1 ·
We have a 1955 Chevy pickup. Previously was built with a 305 and Th350 trans. Motor was getting tired and of course had no power to begin with. So we found a "good" 350 with low miles that should be drop in ready. Cleaned it up, visually inspected the internals and things looked good for the swap.
Majority of everything from the 305 swapped over. The only thing different is that the 350 had the stock 168 tooth flywheel which would also require a different starter. The torque converter from the TH350 bolted to the flywheel with no issues. Picked up a new (reman) starter from O'Reilly's. Installed with no issues and yes have the support bracket.
We went to start the motor and there motor stuggles to turn over and it sounds like metal banging on metal every time it turns over. The motor hasn't fully started just because it sounds "painful" to turn over.
We can easily turn the entire assembly by hand. No grinding, no noises, and turns smooth. Pulled the distributor just to look and looks like new. Pulled the starter and had it tested last night and it spins fine. But I'm still convinced when under a load the starter is causing the horrible banging.
The teeth on the flywheel look great. No damage.

Any thoughts? New starter is coming today. Is it just not aligned correctly? If there was a bolt or something from the torque converter hitting, we should be able to feel it when turning over by hand.

Out of ideas....or just frustrated since the rest of the swap went so well.
 

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Stop throwing money at it and redo your timing.
It’s just too far advanced. That’s why it cranks hard.
Easiest way is loosen dizzy and retard it and as you crank it over move the dizzy until it fires.
Or do it the long way.
Pull #1 plug, bump it over until you feel compression, line up the timing tab/balancer mark and then advance it slightly and crank it up.
Once you get it running adjust your timing and lock down the dizzy.
 

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Discussion Starter · #4 ·
I don't think timing has anything to do with it. Had #1 at TDC and lined everything up, no go. Advanced and retarded it, no go. Pulled distributor and put in 180 just to make sure it was on TDC and massive backfire out the tail pipe, so we had it correctly. Also pulled the distributor and compared it to the one it came with and it all matches up. Even cranked the engine with no distributor in it an still had the horrible banging noise.
 

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Since the flexplate came with the motor and is an unknown quantity, I would suspect that it is cracked and that's what is making the noise. The motor may have been for sale in the first place because of the cracked flexplate. Cheaper and cheaper seems to be the tendency today and with cheaper comes thinner. With thinner comes easier to crack. If it is cracked, it will be from the bolt holes where it bolts to the crankshaft through to the large center hole in the plate and may be difficult to see with the naked eye. The fix is to use a flexplate that is rated SFI 29.1 that is rated for drag racing. SFI 29.1 is the specification for flexplates. These racing plates are made from thicker material and will not crack as easily as a stock plate. Any auto supply will know what you are talking about and the racing plates are easily obtainable. Hope this helps.
 

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Discussion Starter · #8 ·
Thanks for the feedback. We unplugged and even pulled the distributor with no change.

I'm still leaning towards a flexplate/Starter issue. But I'm thinking the flexplate that came with the motor "should' be OK. The motor only had 68K miles on it out of a 71 Impala. The car itself rusted away, so the motor was pulled. The owner had it for over 20 years with no issues. It was his fathers and there was a pretty strong level of trust in place when we purchased it that there wouldn't be any issue.
 

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Shooting fuel out of the carb like that makes me thinking a intake valve is being open when it should not.

I just played with this on my lawnmower with a opposed twin. After blaming the coil and replacing it. Then blaming it on the carb and replacing it. I figured it was a valve so I checked compression and found one cylinder had none. I pulled off the heads and found this;



Removed the bolt that holds down the intake/air cleaner that fell down the carb and reinstalled everything. Checked compression and it has a solid 120lbs.
Engine runs great now. Those little things will get you every time if you overlook them.
 

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Since the flexplate came with the motor and is an unknown quantity, I would suspect that it is cracked and that's what is making the noise. The motor may have been for sale in the first place because of the cracked flexplate. Cheaper and cheaper seems to be the tendency today and with cheaper comes thinner. With thinner comes easier to crack. If it is cracked, it will be from the bolt holes where it bolts to the crankshaft through to the large center hole in the plate and may be difficult to see with the naked eye. The fix is to use a flexplate that is rated SFI 29.1 that is rated for drag racing. SFI 29.1 is the specification for flexplates. These racing plates are made from thicker material and will not crack as easily as a stock plate. Any auto supply will know what you are talking about and the racing plates are easily obtainable. Hope this helps.
I guess the question is did anyone check the flexplate before bolting stuff together or was it already an engine/transmission assembly? And are you absolutely positive that no one in the past dropped something down the intake?
[/QUOTE]
 

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Those of you who don't know what they're talking about are particularly aggravating to those of us who do know what we're talking about. I was an SFI Silver Certified Technical Inspector for over 20 years and I can tell you for sure that SEMA stands for Specialty Equipment Marketing Association and that SFI stands for SEMA Foundation Incorporated. SEMA was formed because there is strength and safety in numbers and SFI was formed to add credibility to SEMA. Please educate yourself.
 

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Those of you who don't know what they're talking about are particularly aggravating to those of us who do know what we're talking about. I was an SFI Silver Certified Technical Inspector for over 20 years and I can tell you for sure that SEMA stands for Specialty Equipment Marketing Association and that SFI stands for SEMA Foundation Incorporated. SEMA was formed because there is strength and safety in numbers and SFI was formed to add credibility to SEMA. Please educate yourself.

Yep - you are correct - it really pisses me off when people don't know what the hell they are talking about.

From the SFI Foundation:

"In time, the need for yet a more sophisticated specifications program became apparent. In 1978 a new organization, the SEMA Foundation, Inc., or SFI, was formed to replace the Service Bureau, chartered to organize and manage an expanded industry specs program. That name has been shortened to SFI Foundation, Inc.


Although a proud beginning, SFI now operates as a foundation completely independent from SEMA, which is now called the Specialty Equipment Marketing Association. SFI no longer stands for SEMA Foundation, Inc. since they are no longer affiliated."
 

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Yep - you are correct - it really pisses me off when people don't know what the hell they are talking about.

From the SFI Foundation:

"In time, the need for yet a more sophisticated specifications program became apparent. In 1978 a new organization, the SEMA Foundation, Inc., or SFI, was formed to replace the Service Bureau, chartered to organize and manage an expanded industry specs program. That name has been shortened to SFI Foundation, Inc.


Although a proud beginning, SFI now operates as a foundation completely independent from SEMA, which is now called the Specialty Equipment Marketing Association. SFI no longer stands for SEMA Foundation, Inc. since they are no longer affiliated."
I remember who you are now, you're the guy who has made it his job to nit-pick everything I say on this forum. I called over to SFI and spoke with Mike, who explained to me that the divorce between SFI and SEMA took place about 1982. I didn't join the SFI tech crew at NHRA until 1990, and everything that was explained to me was just what I replied to everyone on this thread. I will not knowingly tell anyone a falsehood, but many times I repeat things to others that I have been told as truth. I guess that now, with you riding my ass over every little thing I say, I'll have to do closer fact checking or else just not respond in a way that you can fact check anything I say. Thank you for making life a little more difficult for me, I hope you feel really good about making things more difficult for an old man.
 
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