New Gen I block, new EngineQuest vortec heads with guideplates, comp Extreme Energy cam, Crower lifters, 1.52 Magnum rockers and .050 over pushrods (the .050 over pushrods put a witness mark in the middle of the valve tip). With this set-up, the flat top of the rocker-ball is at the bottom of the 3/8" stud threads (without the nut). I've heard of Ford guys using a bushing (fit washer) on top of the rocker-ball to move the nut up on the stud. I cannot find a reason for the problem. Any help is greatly appreciated.
Did you add the guide plates? They may not have allowed for them in machining and intended them to be used with self guided rockers.
Are the studs specific for full rollers? You definitely can't run it without the rocker arm on there correctly and I have seen people shimming the rocker down (nut up) with a good bushing, but I would make sure there isn't something tricky about those heads/guides/studs/rockers first.
These aftermarket studs actually have a tiny bit more threads than the OEM ones. My machinist is trying to find out the problem and may get one vortec head to measure the stud boss, etc.
Ok I thought it was you again as I went back and checked previuos post. From the pic you put in your last post ""It sure looks like the head is not milled enough on the rocker arm pads to accept a screw in stud plus a guide plate as you stated before that the bottom of the rocker was almost touching the jam nut on the stud. The only way to cure this is to mill more off of the rocker arm stud boss on the cylinder head >>>>.
I'm pretty sure those heads are intended to be used w/a self aligning rocker arm and no guide plates, the guide plates may have been installed mistakenly. You can machine the bosses down Like Engine Pro said or probably just buy different rockers like Comp # 1418-16 and remove the guide plates. Whatever is easier for you.
Yep.....you Da Man!!!!!!! If the studs and guideplates are added......you drop in your pushrodswith the heads on, and you gonna run roller rockers.....then when you adjust your polylocks as in setting your valves.....you should have quite a bit of adjustment left. YOUR NOT RUNNING A SMALL BASE CIRCLE CAM, ARE YOU???????? You'd run way out of adjustment before even getting close. When you mill for guideplates and studs......measure from your head bolt seat thats reall close by......ot from your spring seat. I usually get the endmill and touch off the head bolt seat and come up from there.....
I've seen many a dropped valve cause the geometry was off and just tr ied to rig it up........go thru one thing at a time.....and look closely........at all the parts.....even lifter height can really mess you up.............
Ran out in the shop.....we got a engine on the stand like your putting together.....basically the same thing.....I looked it over, here's what to ckeck..... 1. On the early heads, the head bolt thats right between the studs there....the bottom of your guideplate ought to be really close to the head bolt seat there.....within a 1/8, just by glancing at it. 2. Make sure your pushrods and lifters are the same ht, and if the cam base circle is the same as your old one......there's only 2 things it can be.....block ht. is tall or the valve ht. is different. This could be either from machining for taller valves or different heads that have valve area too high. This can get complicated unless you know valve geometry and machining........just check it out close. Even check out your Rockerarms......someone could have had a bad day at the factory and sent you a wrong part or a bad part. Doesn't happen very often....but sometimes it does. Usually.....its a big boo-boo............
I have a very similar set up except for I did not run guide plates and ran self aligning rockers but my motor has 100 thousands over push rods which I got from speedway, and everything worked fine. Maybe the longer pushrods will solve your problem. Tator
It sounded like the rocker was running the center of the valve, so a longer pushrod would only put the pressure over the edge... Wouldn't go that route.
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