new heads are INSTALLED!!

TinManSC92

Registered User
As I said, I just finished up the cars new headgaskets( even though the old ones were in great shape) and installed the new heads that were done by D.D. yrs. ago.
larger exhaust valves S. S., beehive springs, ported, 2'' exhaust manifolds. but now the car seems to run rough.
do you suppose I need a tune or just missed a vaccuum line somewhere?? yikes!!
ALLAN!!! Lol
 
As I said, I just finished up the cars new headgaskets( even though the old ones were in great shape) and installed the new heads that were done by D.D. yrs. ago.
larger exhaust valves S. S., beehive springs, ported, 2'' exhaust manifolds. but now the car seems to run rough.
do you suppose I need a tune or just missed a vaccuum line somewhere?? yikes!!
ALLAN!!! Lol

Could be combination of both
 
Running rough

Is valve height & rocker's still stock? Maybe push rods too long or short for this application .
 
As I said, I just finished up the cars new headgaskets( even though the old ones were in great shape) and installed the new heads that were done by D.D. yrs. ago.
larger exhaust valves S. S., beehive springs, ported, 2'' exhaust manifolds. but now the car seems to run rough.
do you suppose I need a tune or just missed a vaccuum line somewhere?? yikes!!
ALLAN!!! Lol

It's not as simple as bolting on modified heads. Did you set up the all the valves? Like Doug said, pushrod lengths correct? Did the heads have ratio rockers installed? Dave Dalke could point you in the right direction for the info you need. I think you are going to have to look deeper than a vac leak. And you will need a tune. At least it runs. That in itself is a good thing.
Alan
 
Even if the valve train geomitrey (rocker ratio,valve height, etc.)hasn't changed, its possible that the new spring tension was too much for the stock push rod's & bent them.Hopefully it's just a vaccum leak.
 
Is it rough at idle or always.

Compression test should tell you if you have a valve train issue.

You could try soap and water (not real realiable unless its big) on the IC tube joints to see if anything is happening there. You may also be able to try duck tape to get 10 of 15 seconds of clean idle before it leaks again.

Double check your plug wires at the coil. You could have been led down the wrong road with 5 and 6 if useing Chilton/ Haynes

Confirm plug boots are tight as they may arc inside the boot.

Visual for fuel leaks at injectors. (not seated or bad o ring..retaining clips misaligned).

Double check electrical connections are snug.

Good Luck
Paul
 
if not a vacuume leak Id say check lifter preload. I had to shim rockers and get custom pushrods when using those heads
 
Well thanks for all that info. overload guys. Guess I'd better do some light reading. :eek: And, check out what Dave does to these heads to make them as they are. I wasn't under the impression they were all that different but, by the sound of the engine now.... see'' glorious'' and the new info. I better find out huh.
 
Its not that. But between milling a head, installing new valves, new cam...Things change. All you need to do is check lifter preload to rule out needing new pushrods or rockers shimmed
 
A few years ago when I did heads on my 95, after the install the car was running only on 5 cylinders. At that time I was using the stock cam, I had all the hardware for the car to run with the new heads(bigger valves) with the stock cam. It turns out the the guy who had done work had one valve stem longer than the others. That caused one valve not to close fully, I had to shim the rocker to fix that issue up. But on the plus side, after that was done the car ran very well and put down good enough power.

Oh, I forgot I also purchased lash caps too.

Hope you can narrow down the cause soon.
 
Problem solved!! Thanks boys.It seems that I forgot to connect two hoses on the inlet plenum. Runs like a charm now. Stupid me. Don't know how I could have missed those. :eek:
 
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