Drill heads for 3/8 pushrods or no...
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Joined: Jan 2010
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From: Hurley, VA
Drill heads for 3/8 pushrods or no... With my cam and heads set up the motor shouldn't see over 6800, Torquer 2 and PRC 215s. Its 99 percent street car but after a valve dropped I had the head repaired and I'm going to get them tomorrow. While I have it apart would it be worth going to a 3/8 pushrod. I've all ready got every size imaginable in a 5/16. Would there be any issue drilling the pushrod holes to 1/2 inch and still running the 5/16 pushrods for a while if I do decide to clearance them for 3/8.
You can't go wrong with larger OD pushrods. Someone on here just clearanced his pushrod holes I think in 243 heads to 1/2". Might want to contact him and see how he made out. 5/16" in the larger hole won't be an issue, however they will flex more than 3/8" at that RPM with the stiffer springs.
With my cam and heads set up the motor shouldn't see over 6800, Torquer 2 and PRC 215s. Its 99 percent street car but after a valve dropped I had the head repaired and I'm going to get them tomorrow. While I have it apart would it be worth going to a 3/8 pushrod. I've all ready got every size imaginable in a 5/16. Would there be any issue drilling the pushrod holes to 1/2 inch and still running the 5/16 pushrods for a while if I do decide to clearance them for 3/8.
Why not, while they're out? Only need 7/16" on the intake side if it makes a difference to you. Definitely, 1/2" on the exhaust side or they'll still rub (3/8").
With the PRC 215 aftermarket cylinder heads they may not need much clearancing at all to fit the larger pushrod. At the end of the day I don't think going to the 3/8" pushrods is a must, but its not a bad idea either.
I've ran 3/8" pushrods in my 243 heads without additional clearances for well over 30,000 miles. There used to be some pushrod deflection test floating around on wall thickness vs diameter. Run the largest diameter you can fit and don't worry about spending the extra money on thick wall pushrods. You should see the deflection for a 5/16" standard wall pushrod on a spintron at 7000 rpm... can you say noodle?
