ok so here goes i posted up here a few weeks ago and i got a response from madjack i believe it was about some head modification. i got the head on my car milled, ported and polished and ws curious as to how much to get it milled. he had said that if i went over .015" that i would run into so lifter pre-load problems and as i found this out, the fu@ker that had my parts milled .040" off of the head. well now that everything is back together i am of course having problems. fist off the idle sux and anything under 2400 rpm sux as well anything above that it runs pretty smooth. it was throwing a code so at work i hooked up a tech2 to it and it was throwing the p0342 code,(i think that is what it was) anyway where it says the voltage reading to the cam sensor is bad so i tested the voltage everything is good there so i replaced the cam sensor. i have yet to clear the code to see if that fixed it though. i am just looking for some input because now it is making some ticking and i am afraid to drive it anywhere. my thoughts were to take some shims and shim the rocker stud up .025-.030" to try and compinsate for the fact that it has been milled to much and just hope that it takes care of the ticking but i am lost i am asking everyone that i know for input to see what they think

any help would be highly appreciate

thanks again

dave

First, use that Tech2 to clear the code, if it hasn't cleared itself. While hooked up to the Tech2, review you sensor readings, are they within spec?

Is it still idling rough? If so, it's probably because the compression ratio is too high for the cam. The P&P may affect it to, if it was a more radical job. You may have lost the intake air/fuel velocity, which would also affect the vacuum.

The ticking is probably from too much lifter preload. You could shim the rocker arm studs, but you might run into a problem of side loading the valve stems, if you are still using the stock rocker arms. While this isn't a major problem, it would wear on the valve stem guides.

Another option, would be a roller rocker conversion, which would give you adjustable rocker arms. The advantages here would be the roller trunnions and tip for reduced frictional losses(not so much for the tip though), more accurate rocker ratios and increased valve lift, with the 1.6 rockers. You will have to change the studs to do this. If you get the 1.6 rockers, while the studs are out, remember to grind about 1/8" from the guide pocket closest to the stud, on the guide plates. This is because the pushrod pocket is moved closer to the pivot point.

More info on the rocker arms can be found here.

Sounds like you pretty much nailed it head on. The guy who did this job must have either been incompetent, an idiot, or someone didnt give him the .15 instructions only. Run a compression test, my bet is that the compression is higher and with the P&P the airflow has been radically altered, and perhaps the cam just is to mild for your setup now. We are doing a head right now P&P, 5angle valve grind and heat treating it so that we can run higher boost. This also entails better valves and valve springs along with roller rockers. Most of my experience is in the 4G63 DOHC, so i lack experience with OHV engines, but i used to work on the classic v8s so its not so foreign.

BTW anybody seen a vortech style supercharger that comes stock on a car or truck. I want to customize a stock supercharger for my Jbody but dont wanna shell 3900 for the kit.

already thanks for the input, i got a friend coming over tomorrow to help me look it over, i will then do a compression test and see what that says. i am not sure if i am going to be able to hook up the tech 2 to it again though b/c i do not want to drive it in the condition that it is in and my work is pretty tight as far as lending out tools like that goes.....so i will have to see about trying hard to borrow it or just haul my car there with a dolly or something.

i will let you guys know what the compression is tomorrow and see if you have anymore insight for me.

i will def have to look into doing that roller rocker conversion though, i suppose i won't have that much of a choice.

thanks again and i will keep you posted

dave

A compression test won't help you (unless you have a sealing problem). Your compression really wouldn't have been affected that much by shaving the head (my calculations show it would be about 9.5:1 max now), and unless you had the numbers your car was making before the head changes, you have nothing to compare the test to...
I agree with clearing the codes, checking for more, and doing a roller rocker converison to clear up possible valvetrain problems.



fortune cookie say:
better a delay than a disaster.

already well i haven't gotten a chance to tinker with it that much but i am going to today. i am getting new GM o-rings for the injectors b/c i think the ones that came with my head set looked alot thinner, and possibly may be letting to much fuel in. also i am going to double check the power to the camshaft sensor and make sure that that is good. and i have already replaced the cam sensor. does anyone have any idea what else could be throwing that code? that has got me baffled.

thanks again

dave

also the ticking is only after it has gotten warmed up.....do you think i could get away with backing off the rocker nut about 1/8-1/4 of a turn??

thanks again

ok...well i don not know if anyone is still interested but.....after checking a few more things i pulled a compression check and my numbers went as follows.....170-190-50-0......so i knew something was obviously wrong. i pulled the valve cover off and the rockers on the last two cylinders were rock hard just about i could not move them at all. i then proceeded to pull the head back off and sent it somewhere else and had it checked. everything checked out fine on the head. so now i was like great what the hell am i going to do now?? i did some more searching on the web and talked to a few more mechanics that i know and i then pulled the lifters and checked those. most of them i could not even push in at all....so i was like great more $$$ i bought some new lifters and gaskets and i will hopefully be putting it back together tonight and i am also putting in a head gasket shim as well... so hopefully everything turns out ok....if you have anymore input before i put this back together tonight please let me know......i will keep you posted

thanks again

dave

I'd find out what caused the lifters to seize before putting it back together...



fortune cookie say:
better a delay than a disaster.

well...the car ran like crap the second that we fired it back up....so i am under the assumption that those lifters were bad to begin with possibily?? i do not know. the rockers for cylinder 1 and 2 seemed to be fine, it was only number 3 and 4 that were giving me trouble. i am hoping that with the shim back in there and the new lifters that everything will be fine...is there anything else that i can check???

thanks again

dave