Creetan

I have searched and searched on here with no luck so posting my problem.

I bought a motor that the owner claims was freshened up a couple weeks back. The owner had put some GT40 iron heads on it that he had ported with bigger manley valves and 5 angle valve job. He put a B Cam in it. He also converted it to stud mount roller rockers. I put the motor in last weekend. Got it fired up yesterday and noticed alot of valvetrain noise and lack of power. I adjusted the valves((when exhaust started going down and I adjusted the intake and when the intake went down and started going back up I adjusted the exhaust)). When I first started it up it sounded great. Little bit of valvetrain noise but not alot. The problem... I go out this evening to take it for a drive around the block and never make it out of my driveway. When I started it she sounded like crap and alot of valvetrain noise now...So I turned it off. Why would have ran good after the adjustment but after letting it sit over night it gets worse and louder? Need to be adjusted again? Any ideas at all at this point? Oil pressure is 63 cold idle and about 30 warm idle.

AdderMk2

pull a valve cover off, remove a couple pushrods and roll them across a flat table


they are probably bent

mjr46

if no push rods are bent, check the geometry

Creetan

ok I pulled both pushrods from the #1 cylinder. 1 was slightly bent could hardly see it when I rolled it on a table. The other was bent noticeaby. By the noise I am having I can just imagine how many more are bent and how bad they are. About to go pull the rest now. Question.. What causes a pushrod to get bent? Thanks.

mjr46

improper cam, timing, over adjusted valves, insufficient valve reliefs for the valves installed, proper geometry nees to be checked as well as ptv and if the gt-40 heads were converted to stud mount the proper way to have done such is mill down the pedastal also if a push rod binds in a guide plate that was not properly centered you can have issues as well

AdderMk2

or if hes using stock pushrods with upgraded springs... thats a good way to cause it.


OP, if you wanna upgrade to a good set of PR's for cheap.. measure yours and see what length they are. It they are very close to 6.250" or 6-1/4"... lemme know. I have some trickflow chromeoly pushrods that I have no use for

Creetan

ok called the guy I got it from and got some more info on it. The guy who built the car that the motor came out of originaly sold it to some younger guys bout 18-19 they got it and screwed with it. They screwed with the roller rockers trying to adjust them and thought they ruined the cam bearings?.. They also screwed the entire wiring in the car. They tried to install a Painless system and had no ckue what they were doing. The guy I got it from said he opened up the motor to replace the cam bearings only to see they were in great shape still. He also said he wasn't sure if he adjusted the rockers right when he reinstalled them.. dunno how..it's easy.

Upon removing the roller rockers now I see where the valve stem had actually hit the roller rocker body at some point. I am guessing this is something the younger guys did since the guy I got it from never even got it on the street.

So at this point should I just check the pushrod geometry then get new pushrods and see what she does or am I looking at alot more?

AdderMk2

please read my post... please

Creetan

All 8 pushrods from the passanger side are bent..

Adder I sent u a PM.

Creetan

Got around to taking all the pushrods out. All 16 are bent! About 8 or 9 of the roller rockers have some damge on them. Some from rocker body making contact to the valve stem and some damged from the pushrods while a few were damaged from being too tight. It's easy to tell they did not have it adjusted worth a damn.