How much clearancing work for 3/8" or 7/16" P-rods?

[Nashty]

I'd like to run 7/16" pushrods on the exhaust valves and 3/8" on the intake. I have a set of ported 14 bolt Champion heads. I can't remember what it looks like in there since I managed to keep my head gaskets intact for an entire season.

How much clearancing is required for this? Remember, I want to use 7/16" on the exhaust. Tim Cole recommended this and I'm on board if I can get them to fit.

 

[HighPSI]

I am sure cam lift and rocker ratio come into play, but on mine there isn't much room for the valve cover gasket once I clearanced everything. I run 3/8 pushrods on both intake and exhaust. This is with a GN-1R head. The exhaust is the most critical. I doubt I could get a 7/16 pushrod to fit on mine.

 

[TurboTR]

Good idea Nashty You can also get tapered pushrods in very strong 4140 steel for additional clrnc. Talk to Terry at Manton Racing (son of Sig Erson no less). Speaking of, I have a very nice set of 11/32 straight for the intake and 3/8 to 11/32 tapered for the exh Manton pushrods that I don't need anymore. These are strong, strong. Have the 210 deg ball end for T&D rockers. If the length is right for your app would you consider them? I had them in an 4.1 S2/GN1 app with the short Comp roller lifters.

TurboTR

 

[EightSecV6]

Use an ISKY lifter and you can run a 5/16 one piece pushrod with no problem, lighter valvetrain= more HP!

 

[postal]

Hey Beavis!

What are you looking into the bigger push rods for? Is it a matter of how strong they are? Let me know which ones I should get.

Snap me a few pics of that intake and I'll send you the specs on this cam card so you can go shopping for your new valve springs.

Jason

 

[Nashty]

Originally posted by TurboTR
...You can also get tapered pushrods in very strong 4140 steel for additional clrnc. Talk to Terry at Manton Racing (son of Sig Erson no less). Speaking of, I have a very nice set of 11/32 straight for the intake and 3/8 to 11/32 tapered for the exh Manton pushrods that I don't need anymore. These are strong, strong. Have the 210 deg ball end for T&D rockers. If the length is right for your app would you consider them? I had them in an 4.1 S2/GN1 app with the short Comp roller lifters.

TurboTR

Todd !! I tried emailing you but your email bounced. I ended up running a 50 shot this year.

I have the super exotice sounding "Scorpion" rockers. I tell you what, I'll just trade you for the T&D's and the pushrods. Sound good?

Do you know what length those are? I have hydraulic lifters in the car now but I'd like to put in a set of solids. I have some but they're not the shielded foot variety. I got them in a horse trade.

Post-hole. The larger p-rod's won't flex like the 5/16's do. Tim was very convincing and it makes complete sense to me. If there is any flexing with the pushrod, the benefit of the stiffer rod will far outweigh the reciprocating penalty. The bigger diameter rods have a nice thin wall too. So the weight penalty isn't that bad.

 

[TurboTR]

Oh there is flexing for sure- you should see the divots in my old head gaskets

I will get the length of the pushrods tonight. These things are are like $20-$25 ea new...

TurboTR

 

[TurboTR]

Sorry about the mail, it may still have been set to the old swri.org one for awhile after I left there. The addy that shows up now is good Or turbotk2001 on yahoo IM and mail.

TurboTR