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Engine basics => Engine set up tips => Topic started by: Phil Coopy on July 29, 2006, 06:15:20 PM
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If you upgrade to an ABC piston/liner setup do you still use the 29% lube mix?
Phil C
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Good question, I'm not sure if 29% is needed, but remember you have
an unbushed rod and a plain bearing engine.
Walter
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Good question, I'm not sure if 29% is needed, but remember you have
an unbushed rod and a plain bearing engine.
I don't know for sure, either, but I would be very surprised if synthetic didn't to a better job of lubrication of the "cold" parts than castor.
Another question that I don't know the answer to is, is it still a 35? The stock liner is *awfully* thin-walled and I would be a little surprised if you could make a brass one the same dimensions without it getting distorted.
Brett
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Brett, I think somebody measured one and it turn out to be either a .30 or .31 . The brass sleeve was thicker.
Walter
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Another question that I don't know the answer to is, is it still a 35? The stock liner is *awfully* thin-walled and I would be a little surprised if you could make a brass one the same dimensions without it getting distorted.
Brett
Another liner that is *awfully* thin-walled is the Ro-Jett 65 Liner, but it works fine for me and a lot of other people.
I had a Fox 36 mk5 that was worn out, and bored and honed the liner to fit a Fox compact 40 piston. I could feel the stone rotating inside the liner when I was honing it. When it was finished it had a very thin liner !
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I don't know for sure, either, but I would be very surprised if synthetic didn't to a better job of lubrication of the "cold" parts than castor.
Another question that I don't know the answer to is, is it still a 35? The stock liner is *awfully* thin-walled and I would be a little surprised if you could make a brass one the same dimensions without it getting distorted.
Brett
HI Brett
Yes with FOX ABC parts it is still a 35, and the FOX 35 head will still fit, along with my hemi head design . however with some of the aftermarket parts , it is closer to a 30, these are thicker sleeve parts, and they send you a new smaller head.
Also yes I have found that part Synth. part castor in 28% work better not only in ABC Foxes but also in the standard FOX 35. I have one here that I bought in 1971, It is still in good shape after 100s of runs, even in the heat of Lake Charles NATs. It has only run on 75-25 castor Synth blend 28%
Randy
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HI Brett
Yes with FOX ABC parts it is still a 35, and the FOX 35 head will still fit, along with my hemi head design . however with some of the aftermarket parts , it is closer to a 30, these are thicker sleeve parts, and they send you a new smaller head.
Wow, that must take some pretty careful handling to keep the sleeve from getting distorted. Thanks.
Brett
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The aftermarket must be what I was thinking of.
Walter
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Wow, that must take some pretty careful handling to keep the sleeve from getting distorted. Thanks.
Brett
You can push the sleeve in a steel holder while you hone the sleeve, helps keep things round.....then again it is going in a Fox 35 case?????
Randy
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I've had good luck using standard Fox 35 fuel(28-29% oil) that I've never tried anything less. It's still a Fox 35. I think the extra oil is still needed for cooling and to get the proper balance of 4-2 stroking.
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I would stay with at least 25% total oil, and 28 to 29% preferred. I ran an ABC Fox on 22% half and half castor synth., for a while, and the wrist pin bosses wore out pretty quick. This was one of the earliest ones, so don't know if they have been improved or not. Not much bearing surface for the wristpin in the aluminum piston. They sure do run nice on profiles with that setup though.