Flexplate gap bbc
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Flexplate gap bbc
I switched to a sfi flexplate on my new 454 build. I have .093 air gap between flexplate and converter. Called coan and they don’t seem excited about milling the pads. Is this normal or what? I can’t get a straight answer on what to do. With the stock flexplate I had .125
Re: Flexplate gap bbc
If everything is correct, the converter bosses must be configured for a midplate.
A novice machinist with a lathe can clean it up for you.
A novice machinist with a lathe can clean it up for you.
Magnús Aðalvíkingur Finnbjörnsson
Re: Flexplate gap bbc
I always ran a washer on my SBC stuff that would take up most of the space and a big enough diameter to cover most of the mounting surface. I have seen some guys just draw them up tight, probably why you see guys with cracked flexplates.Jatmobkar wrote: ↑Sun Jan 12, 2020 3:07 pm I switched to a sfi flexplate on my new 454 build. I have .093 air gap between flexplate and converter. Called coan and they don’t seem excited about milling the pads. Is this normal or what? I can’t get a straight answer on what to do. With the stock flexplate I had .125
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Re: Flexplate gap bbc
Is .093 a problem ??? If you were using a stock type flex plate before there is a good chance it was not very straight anyway. I have always figured that as long as there was some clearance it was good to go.
Bill Koustenis
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Re: Flexplate gap bbc
SFI flexplate is thicker than stock. That explains the difference. DO NOT shim the converter away from it. You need that room to prevent the converter from bottoming out in the pump. You can have the pads machined down on the converter for additional clearance if you need it. SFI flexplate won't flex as much as a stock one though. I've never had an issue with this.
Mark Goulette
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Owner/Driver of the Livin' The Dream rear engine dragster
Speed kills but it's better than going slow!
http://www.livinthedreamracing.com
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Re: Flexplate gap bbc
I've run as little as .100 on mine with no issues. In a pinch, I'd run it.Jatmobkar wrote: ↑Sun Jan 12, 2020 3:07 pmI switched to a sfi flexplate on my new 454 build. I have .093 air gap between flexplate and converter. Called coan and they don’t seem excited about milling the pads. Is this normal or what? I can’t get a straight answer on what to do. With the stock flexplate I had .125
If not, set it up on a mill, take .030-.035 off and sleep better. Little details like this are what bite you later.
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Re: Flexplate gap bbc
I would go with the .093 gap as well. All that is needed is for the pump drive not to bottom out in the pump housing and tear metal off. Good converter that does not balloon and a ridged flex plate, you should have no issues. I am not sure how the converter companies jig their units before welding, but I seldom see the same gap from converter to converter. Most of the time if there is an issue I get nervous, is too large of a gap and have to add washers. Mopar transmissions have the shortest distance in the bell housing, and many times I have gotten converters that had no clearance.
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Re: Flexplate gap bbc
For being so persnickity about other things I feel bad that I never measured that clearance.
I never saw the need.
Heck I never saw a spec written on this.
As long as I had some everything always worked like it was supposed to.
Chances are if it is .093 on one pad it might be .150 on another due to the "flex".
I never saw the need.
Heck I never saw a spec written on this.
As long as I had some everything always worked like it was supposed to.
Chances are if it is .093 on one pad it might be .150 on another due to the "flex".
Dave Koehler - Koehler Injection
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Re: Flexplate gap bbc
I had one that ended up at .065, but ran it, it was OK but I pulled it & had it restalled & thought I told the conv. gut to take .030+ off but he didn't.
Chucked the snout in the lathe & to some off myself.
Chucked the snout in the lathe & to some off myself.
Jim
Re: Flexplate gap bbc
Shortening the convertor hub would decrease the convertor-to-flex plate clearance, assuming the convertor hub was 'bottomed' in the crank counter bore.
Which they rarely are........
Re: Flexplate gap bbc
Took it off the pads.
Jim