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Tech / General EngineIs your car making a strange sound or won't start? Thinking of adding power with a new combination? Need other technical information or engine specific advice? Don't see another board for your problem? Post it here!
Hey everyone. After having some issues getting the car to run I finally got it to fire up but I am still having issues that seemed like timing. I popped my valve cover off to check for #1 TDC and I noticed how loose my full roller lifters were. When I installed the engine in the car, I checked them and they weren't that incredibly loose. So one of two things could be happening that I can think of. One, I didn't torque down the lifters to proper specs and they are loosening up, or two, the push in head studs are being pulled out of the head.
I'm running vortec heads with GMPP LT4 hot cam with Comp cams 918 springs, Proform 1.5 full roller rockers. With the locks and retainers, I should be built for .625 lift max if I remember correctly, but I'm only using .492/.492 278/287 at .50. I think stock vortecs are made for .428 lift on the exhaust but don't remember exact specs.
Has anyone else ran into this problem? Is going from .428 lift to .492 too much for stock push in head studs? Or should I just readjust the valves?
Friend at work suggested getting a girdle to brace them, and it makes sense to me because then each lifter would have the strength of all the studs to hold them in at any given time. Looking for advice on what I should do. My timing issues most certainly have been because of the incredibly loose rocker arms not working the way they should. Thanks.
Look at the top of the guides and the bottom of the retainers. If there's interference (sounds like there likely well may be) then a stud girdle isn't going to fix it. Design choices that result in moving parts bashing into castings is never a recipe for a successful engine build.
You think the rockers could be hitting the valve locks and retainers? I can't remember the exact comp part numbers I used. Built the engine three years ago.
I noticed today my brand new lifters aren't even pumped up, what could be causing that on a new engine with good oil pressure? Running hydraulic roller.
All the issues I was having before was caused by a bad pick up coil. And since I replaced the distributor I've seemed to open up a big can of timing/valvetrain problems. Never ending, the car should have been on the road over two months ago. I plan on working on it when I get off at 6 am, I'll look at things again closer tomorrow. I just don't want to get in a rush and tighten everything up and drive it and blow the valve train to pieces. I spent close to a grand on just it alone.
Last edited by FireInMe17; 06-03-2016 at 03:13 AM.
Reason: Spelling
Readjusted the valves today, boy were they out. Don't think the engine builder adjusted them right. Pics are with #1 intake fully open and exhaust fully seated obviously. Plenty of clearance, and the studs don't look like they're pulling out. I think they were just way put of adjustment and instead of opening and closing smooth they were just smacking open really quick and that's why it only wanted to run wot because that's the only time any air was getting in to make a difference.
I'd still be worried about pulling a stud out. When I rebuilt my heads I put pins in to make sure the studs won't pull out. I wish I had it in my budget to get screw in studs but at the time I didn't.
I think you should at least put pins in just to be safe.
I'll have to look into getting them pinned because I don't want to have to worry about it either. I still have to change my oil and put it all back together but here's to hoping it's right now, it feels a lot better that's for sure!
if you lay a straight edge across the top of all 8 adjuster nuts, are they all about the same? i've seen where guys have put a trunion upside down before by accident. sounds like you had to go over the builders work?
somebody used to sell clear valvecovers but i think they would turn yellowish after a while.
I know the guy personally, and I graduated with his son but he told me they were a pain in the ***. He asked me if I adjusted them when he came and helped me fire it for the first time so maybe he expected me to do it haha
Only reason I didn't get the 1.6s was because the vortecs need machining to fit them, and I didn't think it was going to be that big of a difference between .525 and .492 lift. Whenever I get bored I'll take the heads off and p&p, gasket match, and do the machining so I can run the 1.6s. Next upgrade to the engine is the high flow runners like you have. Didn't have the budget when I was building it. Redid the entire car mechanically December and January.
I'll def be getting a pair for the 350 TPI I'm building for the 79 K5, and maybe the Silverado will need them too. I know all of them are gonna need long tube headers and K&N.
I'm running a stock L98 Bottom end with a Stock LT1 cam. I ported the heads, cut the Valve guides for more lift, Pinned the studs and Put new 1.94/1.50 SS swirl polished and back-cut valves in with new springs and 10 degree locks and retainers. I ported the stock TPI base and plenum and ported the slp runners. I have 24lb injectors on it and run the super-aujp prom developed by members here.
I'm currently completely redoing the suspension and brakes. LS1 Fronts/ LT1 pbr rears.
I'll probably through up a post on that once I'm finished complete with pics.
I also have a LT1 from a Impala sitting that I am thinking about rebuilding and replacing the l98 with but thats at least 2 years away.
06-01-2016, 04:16 PM
