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FE Power Forums => FE Technical Forum => Topic started by: fe66comet on August 09, 2014, 11:43:49 AM

Title: 4.25 FT crank?
Post by: fe66comet on August 09, 2014, 11:43:49 AM

Does anybody make cranks in the 4.25 stroke with the big snout? I was just sorting through my extra parts pile and it got me thinking about using some of it on a FT project.

Title: Re: 4.25 FT crank?
Post by: KMcCullah on August 09, 2014, 05:27:18 PM

Huh? I don't think so. But if you wanted to I guess you could make an adapter sleeve for any FE crank that would let you use an FT damper. You will have balancing issues.

Title: Re: 4.25 FT crank?
Post by: fe66comet on August 09, 2014, 06:11:27 PM

I would get it all spun balanced anyhow. I would go forged for sure but I wonder if strength at the front would be an issue?

Title: Re: 4.25 FT crank?
Post by: My427stang on August 09, 2014, 06:16:47 PM

I think the bigger issue would be that the heads don't flow.  If I were to build an FT, I'd try to get overall airflow up before I added cubes.

A stock, I would think, never did it, would wake up quite a bit if you cleaned up the heads and made a set of headers that bolted to the exhaust flange.

Dump the governor, put some real valve springs on it and let it sing at 4500 rpm :)

Title: Re: 4.25 FT crank?
Post by: fe66comet on August 09, 2014, 08:29:19 PM

It looks like the shorter, smaller crank snout would limit using an FE crank, diameter could be overcome but you can't really add length reasonably. I suppose a little could be gained by welding the journals and regrinding but still for the small gains to be had it would be hardly justified. The only way I could see it working is if a rough forging were available to start with. I think most my gains would be better had on compression, top end and exhaust. I am looking for all torque anyhow so I will concentrate on that.

Title: Re: 4.25 FT crank?
Post by: cjshaker on August 10, 2014, 02:31:08 AM

Sure you can get one. They're called "billet" cranks and you can have them made any way you want. Just save up your aluminum cans.

Title: Re: 4.25 FT crank?
Post by: fe66comet on August 10, 2014, 05:03:40 PM

I looked at SCAT and they could do it, I sent the specs to get a quote. If you wanted a new FT crank of any sorts that is what you would have to do anyhow. The only new crank available would be custom aftermarket. The difference is 1 3/8 vs 1 3/4 snout and the length I am not sure of but it is longer. Also the pilot bearing hole is larger and the flywheel flange is heavier. Last is external balance, all is optional on their site under the options list.