Generation IV Internal Engine - PRC head issues? Maybe nothing? Gurus enter
mikegammill
04-17-2012, 09:30 AM
I got my 237cc PRC's in the other day, got em torqued down and was about to slide my pushrods in and then I noticed this:http://i1176.photobucket.com/albums/x331/gammilllmike/th_100_1705.jpg (http://s1176.photobucket.com/albums/x331/gammilllmike/?action=view¤t=100_1705.jpg)http://i1176.photobucket.com/albums/x331/gammilllmike/th_100_1704.jpg (http://s1176.photobucket.com/albums/x331/gammilllmike/?action=view¤t=100_1704.jpg)http://i1176.photobucket.com/albums/x331/gammilllmike/th_100_1707.jpg (http://s1176.photobucket.com/albums/x331/gammilllmike/?action=view¤t=100_1707.jpg)http://i1176.photobucket.com/albums/x331/gammilllmike/th_100_1694.jpg (http://s1176.photobucket.com/albums/x331/gammilllmike/?action=view¤t=100_1694.jpg)
Seems that every intake rocker/pushrod bore is offset to the point of the pushrod being uncomfortably close to the pushrod bore. Exhaust is dead center as seen in the pictures.
Im really curious to see what you guys think about this, maybe it's fine. But it doesn't look fine to me. Any and all input is greatly appreciated.
Thanks, Mike
mikegammill
04-17-2012, 09:31 AM
Let me get those re-sized real quick
mikegammill
04-17-2012, 09:55 AM
Okay, I think the pictures are working. Not very good at uplaoding stuff.
godlyxdan
04-17-2012, 09:59 AM
Did you torque them down in the right order?
There is a specific order that LS heads need to be torqued down in, that might have a little to do with it
mikegammill
04-17-2012, 10:05 AM
I dont think it has anything to do with the torque specs or sequence. But, yes, I absolutely did the head install 100% to spec. I'm leaning toward the machining process, as the threads for the rocker bolt are not lined up with the pushrod bore. The Intake Rocker Threads/Pushrod Bores are NOT in line like the Exhaust Rocker Threads/Pushrod Bores
godlyxdan
04-17-2012, 10:09 AM
well pictures refuse to load through the internet connection im using so that was just a shot in the dark suggestion without actually seeing the problem.
Start with the simple things like making sure the head isnt warped and that your deck is straight and flat.
If that all checks out then pick up the phone
mikegammill
04-17-2012, 10:12 AM
I appreciate the help either way. If you could see the pics you would see exactly what I'm talking about. Looks like I might have to make yet ANOTHER call to TSP, pending some more brains to pick.
Also, everything is new
mikegammill
04-17-2012, 10:15 AM
Here is a link to my photobucket for those that cannot see the pictures
http://s1176.photobucket.com/albums/x331/gammilllmike/
cam75w/ls1
04-17-2012, 11:04 AM
I just bought a set of the 255's and had to use the new rocker pedestals that came w/ the heads. The stock pedestals line the rockers up wrong due to the larger valves. The valve guides were relocated in the head. So I have a $1800 set of Jesels on the shelf that don't work now.
Tony Mamo @ AFR
04-17-2012, 11:33 AM
The pushrod holes are not meant to be centered.....if they were you would have a gaping hole in your intake port. They will always be offset....on PRC, AFR, TFS, etc.
If the pushrods arent hitting the tube (note they can and will be very close), finish your install and get that motor fired up.
There is nothing wrong
-Tony
mikegammill
04-17-2012, 11:51 AM
Hell yes. That's exactly what I wanted to hear!
TVWilkes
04-17-2012, 08:59 PM
Thanks Tony! That is exactly right. The intake pushrod holes had to be moved over a little to clear the intake runner.
azzkker
04-17-2012, 09:24 PM
I just bought a set of the 255's and had to use the new rocker pedestals that came w/ the heads. The stock pedestals line the rockers up wrong due to the larger valves. The valve guides were relocated in the head. So I have a $1800 set of Jesels on the shelf that don't work now.
What is the real benefit of running the jesels or any hyper expensive rocker for that matter as opposed to the cheaper stock style rocker arms?
thanks
anthony
cam75w/ls1
04-17-2012, 09:46 PM
Nothing I would think. It is a customer's car I'm building right now. He thinks running .650 lift AND 1.8 ratio rockers w/ a supercharger is going to get him somewhere. I just about took a baseball bat to his kneecaps to let me grind a new cam at .598 lift w/ the Jesels. Now the Jesels don't fit so now maybe I get to run 1.7 ratios rockers now! I run stock LS3 rockers on my S10 w/ the trunion upgrades and am happy!
azzkker
04-17-2012, 09:55 PM
Nothing I would think. It is a customer's car I'm building right now. He thinks running .650 lift AND 1.8 ratio rockers w/ a supercharger is going to get him somewhere. I just about took a baseball bat to his kneecaps to let me grind a new cam at .598 lift w/ the Jesels. Now the Jesels don't fit so now maybe I get to run 1.7 ratios rockers now! I run stock LS3 rockers on my S10 w/ the trunion upgrades and am happy!
Thats what i figured. Just making sure i was not missing out on some magiacal HP producing part.
thanks
anthony
mikegammill
04-18-2012, 05:08 PM
Thanks again Tony for the quick response. Right after I saw that post I was in the garage, right back to wrenching. Engine is ready to go on the subframe, and sliiide in my z28.
But sadly, now I am waiting on a set of oil pan bolts. If anyone has a set willing to sell, I can think of someone needing them DESPERATELY.
Anyone know if they are special bolts? I have the specs on the long ones and could run to the hardware store, I just don't know if they would be interchangeable.
Thanks, Mike
outkast6991
04-18-2012, 05:51 PM
i have a set of oil pan bolts if you still need them
CAMSTER
04-29-2012, 07:45 PM
clearances, while you wait for your oil pan bolts, this is impotant, check push rod to head interference with the valve open and close position on the push rods wich seem to come the closest to touching, the head pipe, 3 or 4 thows is all you need, then see if the rockrers are not bottoming out at full open possition [ when they are at the lowest point,] should not touch the spring retainer, check at least 2 intake and exhaust valve rockers.