What type of bearings to use?

[cobrashoch]

Lynn - I've used various Clevite bearings with soft cast cranks, with fair to good success.
But in your case, with a forged crank, I suggest I suggest that you use exactly what the factory uses with forged cranks. I.E. - factory bearings. Just make sure you order bearings from a factory forged crank type engine. I'm also assuming you have the stock replacement type H-beam rods. Are you building that engine yourself?
Clearancing the bottom end of a engine is a time consuming art in itself, that requires a machine shop. For a stock type clearance job though, you can "cheat" by setting your rod side clearances to the minium number by using over and under bearings in the mockup. It will take time to work this out because you will have to keep ordering plus or negitive size rod bearings.
I would also use the rod bolts on those rods for the mock up work, but for sure I ditch them for the better ARP bolts for the final assembly for several reasons, most notably you've streched them out during mockup work.
If you are using a pro engine builder I for sure would trust his assembly expierience anytime over using the latest "trick" stiff out there. It's MUCH MORE important to have your engine stay glued together than to have the latest and the greatest stuff.
As for engine coatings, they work. But they tend to to be short lived dependent on where you use them. If your the type that tears a engine down for inspectons from time to time, as I am, then coatings help. If your into long term engine use without teardowns I would not use them. Because as coatings wear out the engines clearances become loose and sloppy, depends on where they are used.
I also like the idea your using on a GT40 of using electronic fuel injection. When it comes time to fire that guy up, I also have some novel ideas on how to get air out of your cooling system. And that WILL be a problem. Good luck.
cobrashock

[cobrashoch]

O.K. Ben. - Then we will see. I don't claim to know much, but I do know what I know. As for spoting a technical peice on a site and excepting it as a cannon, you've got it it all wrong in my eyes.
Those folks can show anything they want to, to get me to use their products. I except such things at face value tempered with the scepticism of my experience mixed in. It's that way with everything I buy, (a product) or with any job that I'm attempting to do. The emphis' is on THEM, not me. I'm the customer.
Getting back to the original stuff I said. When I said it's all about "oil control" that statement stands. Trouble is, the explaination is both long winded and out of the scope of this thread. Don't confuse that with a "lack of proof" response. I can be reached a rnldshock@aol.com if you wish to take this subject further.
cobrashock

[GT4T]

Ron,

Thanks for the reply, my engine machinist tends to agree with you re: factory bearings. In this case, I am not sure that will be possible since crank's rod journals and rod big ends are Chevy size not Ford. (2.100 vs 2.123) He will be doing the machine work on the new R302 and blue printing the parts to ensure proper fit, valve to piston clearance, dynamic compression ratios, etc. I will probably do the final assembly though. I will also be using new ARP fasteners throughout the engine; just ordered stud sets for heads & mains, full bolt set (although I will only get to use about 1/2 of it since ARP doesn't make a late model engine bolt kit.) This will include upgraded rod bolts since this, it seems to me, is as important as the choice of rod type. I would have rather used I-Beam, but couldn't afford the ones I would have had to use, so I compromised with the H-Beams.

I have a fairly stock 5.0L in the car now and have pretty well worked out the air evacuation issue. You are right though: there are lots of guys having heating issues which is directly attributable to not getting and KEEPING the air out of the system. I have bleeds at both high points for the fill process and a swirl pot set up to trap and expel vapor on an ongoing basis (this includes a separate line from the top of the radiator.) The swirl pot overflows to the bottom of a capture tank that releases vapor to the atmosphere, but pulls liquid back in during cool down. I have idled the car statically for several hours with the AC running with the temp being rock solid within the range of the thermostatically controlled radiator (Griffin) fans.

Regards,
Lynn