Northstar rebuild: Will style (Page 16/119)
ryan.hess SEP 09, 11:29 PM
his pistons are clean enough to eat off of

jstricker SEP 09, 11:42 PM
Will,

Just off the top of my head, did you talk to Sealed Power about the proper honing of the cylinders for their rings? They were pretty admant to me about grit and proper pattern to make sure the rings seal. Also, did you use their ring sealing compound on assembly?

John Stricker

quote
Originally posted by Will:

$600 was an off the cuff guess. My harness took about 40 hours, but now that I know what to do and have a well sorted harness to reference, I'm sure I could do it in significantly less time. If you're serious about it, I'd be happy to do it for you.

The question of Caddy PCM vs. Holley Commander basically comes down to the question of stock vs. modified. If you're going to leave your engine stock, the Holley Commander is total and complete overkill, and possibly dangerous to your engine (DO NOT raise the rev limiter on a stock Northstar). If you're going to modify your engine, particularly with ported heads or reground cams, then you'll need the tunability of the Holley, because the Caddy computer, at this time, can not be tuned well.
Will SEP 09, 11:43 PM

quote
Originally posted by ryan.hess:

Maybe I should read this in it's entirety before posting... but did you go for reground cams? Or just want the higher redline?


Just wanted to not crack a lifter if I ever pull off a 3-2 upshift.

Will SEP 10, 08:12 AM

quote
Originally posted by jstricker:

Will,

Just off the top of my head, did you talk to Sealed Power about the proper honing of the cylinders for their rings? They were pretty admant to me about grit and proper pattern to make sure the rings seal. Also, did you use their ring sealing compound on assembly?

John Stricker


When I was ordering I don't recall being advised of proper honing. Rest assured that I've been on the phone with them a few times since the engine started smoking.
However, there is still oil on the backs of the intake valves. Until that's straightened out, I can't say that rings or honing are responsible for anything.

Now when I say "oil on the backs of the intakes", I don't mean that the intakes are a little damp, or maybe glistening. I mean and have always meant PUDDLES of oil on the backs of the intakes. As much as half a teaspoon per valve. Some of the puddles are deep enough to almost get up to the valve stem. Yes, even after the valve stem seal procedure. After a drive with new stem seals and the PCV capped off... STILL oil standing on the backs of the intake valves.

------------------
Punch the gas and feel the back step sideways; rip off a powershift and hear the tires punished by torque; downshift, lift off and feel the engine braking that comes only from big cubes, listen to the pop and gurgle. Know that you are driving an American V8. There are finer engines made, but none that are this cool.

Luck, Fate and Destiny are words used by those who lack the courage to define their own future

Kohburn SEP 10, 08:17 AM
I'm trying to visualize the northstar heads and intake design and oil passages for any clues as to other potential leaks.. i'd say maybe some horrible blowby throwing oil through the intake, but you blocked off the pvc...

is it on all valves? or only some?
sanderson SEP 10, 09:37 AM
Will,

I feel your pain. Is there a pretty good oil coating in the intake manifold as well or are you only finding it on top of the valves?

If it's in the intake manifold have you chased down every line that goes to the intake. For example on an Iron Duke you can plug the PCV but there's a valve cover vent that ties into the bottom of the air cleaner inlet snorkel that will still blow oil into the intake if the rings are bad.

Out of curiosity how's the manifold vacuum at idle.

jstricker SEP 11, 04:31 PM
The oiling system on the Northstar is done through passages at the front of each head and then distributed through hollow camshafts. Other than by the valve stems, there really isn't anywhere for the oil to get to the intake side. The intake manifold at no point is exposed to the crankcase. If Will has disconncected both the PVC hose and the breather hose from the intake system, the ONLY place oil can get on the backside of the valves is by the valve stems.

With new seals, something is definitely amiss in the upper cylinder head area on Will's motor, it's just a matter of figuring out what. One wild thought that occured to me, is the oil draining back fast enough? If the seals are sitting under a sea of oil, then no valve stem seal is going to control that. But that doesn't make much sense to me since Will says it's smoking from both banks and while one side could certainly have drain back passages plugged, the odds of both being plugged, and how they got that way, is a pretty long stretch.

As much as I hate to even think it for Will's sake, I'm afraid the heads are coming back off. Something's wrong here (understatement of the year).

John Stricker

quote
Originally posted by sanderson:

Will,

I feel your pain. Is there a pretty good oil coating in the intake manifold as well or are you only finding it on top of the valves?

If it's in the intake manifold have you chased down every line that goes to the intake. For example on an Iron Duke you can plug the PCV but there's a valve cover vent that ties into the bottom of the air cleaner inlet snorkel that will still blow oil into the intake if the rings are bad.

Out of curiosity how's the manifold vacuum at idle.


jstricker SEP 11, 04:33 PM
You say PCV "capped off". Are you REALLY capping it off, or just disconnecting it and leaving it open to the air? If you're really capping it off, you're going to build up some serious crankcase pressure very quickly. I presume you mean it's Capped Off on the intake side and not the breather side.

John Stricker

quote
Originally posted by Will:


When I was ordering I don't recall being advised of proper honing. Rest assured that I've been on the phone with them a few times since the engine started smoking.
However, there is still oil on the backs of the intake valves. Until that's straightened out, I can't say that rings or honing are responsible for anything.

Now when I say "oil on the backs of the intakes", I don't mean that the intakes are a little damp, or maybe glistening. I mean and have always meant PUDDLES of oil on the backs of the intakes. As much as half a teaspoon per valve. Some of the puddles are deep enough to almost get up to the valve stem. Yes, even after the valve stem seal procedure. After a drive with new stem seals and the PCV capped off... STILL oil standing on the backs of the intake valves.
Will SEP 11, 09:29 PM
For the PCV, the manifold and corresponding valve cover connection were been capped. I left the other side of the PCV system hooked up. I know I need to do things differently... I'll see what I can rig up for a trap to hook both sides of the PCV system to, so that I can eliminate it as an oil path entirely.

It occurs to me that with the cam cover connection capped, blow by from un-seated rings might pressurize the crank case and blow oil out the other cam cover connection and into the throttle body, since that side of the PCV connects to the intake ducting immediately upstream of the TB.

Speaking of ring seating... I just did a compression test.
#1: 200
#2: 190
#3: 195
#4: 192
#5: 202
#6: 200
#7: 200
#8: 200
The manual calls for 140-170 psi.
Mind you, this was a cold compression test (I'm not wild about doing a hot compression test), and the car doesn't smoke nearly as much cold as it does hot.

I forgot to examine the plugs on the front bank, but of the plugs on the rear bank, #7 was black, #5 looked normal, and #3 and #1 were wet with oil.

------------------
Turn the key and feel the engine shake the whole car with its lope; Plant the gas pedal and feel in your chest neither a shriek nor a wail but a bellowing roar; Lift and be pushed into the harness by compression braking that only comes from the biggest cylinders while listening to music of pops and gurgles. Know that you are driving and American V8. There are finer engines made, but none of them are this cool.

Luck, Fate and Destiny are words used by those who lack the courage to define their own future

[This message has been edited by Will (edited 09-11-2004).]

cptsnoopy SEP 11, 11:13 PM
Will,

is there any way to block the oil return from the lifters to the block such as the head gasket holes not lining up or some sort of sealer? could you run the engine with the rear cover off to see if the oil is backing up from the lifter/spring bores? i don't know how much oil this engine would spew out, i have only built and adjusted 1970's engines.

edit: one other thought, is there any chance that oil is pooled up in the exhaust and is smoking when hot?

[This message has been edited by cptsnoopy (edited 09-11-2004).]