Getting ready to pull heads

[tortuga]

Ford racing 427/535
Been eating oil since day 1.
Not a pcv problem, have Walker pcv with catch tank
Replaced intake gaskets half a dozen times
Compression is 215+/- single digit all 8
Replaced all valve guide seals
Plugs look good albeit a little dark

Has to be valve guides?

Question: what’s the best nor cal machine shop to have the heads gone through?

Steve H
SPF 1764

[ERA 626]

shelby engine co in windsor ca

[sea2jet]

Possibly the cylinders didn’t break in properly and are glazed? Been there, but mine smoked at idle once warmed up.

[bobcowan]

Originally Posted by sea2jet

Possibly the cylinders didn’t break in properly and are glazed? Been there, but mine smoked at idle once warmed up.

I had a similar problem, don't know why. I didn't really get much smoke. But it sure drank oil. I honed the cylinders and put in a new ring set. Problem solved.

[sea2jet]

Originally Posted by bobcowan

I had a similar problem, don't know why. I didn't really get much smoke. But it sure drank oil. I honed the cylinders and put in a new ring set. Problem solved.

Exactly the same thing we had to do, actually Danbury Competition Engines did the work on the last cobra I owned.

[tortuga]

Originally Posted by bobcowan

I had a similar problem, don't know why. I didn't really get much smoke. But it sure drank oil. I honed the cylinders and put in a new ring set. Problem solved.

How was the compression?

[tortuga]

Originally Posted by ERA 626

shelby engine co in windsor ca

Are their rates competitive? I know they sure are proud of their crate engines...

Thanks

[Gaz64]

Steve,

Why does it have to be the heads?

What type of guides?

More importantly, what valve stem seal, and are they fitted to both intake and exhaust?

Piston rings can be the cause of oil consumption, wrong fitment, gaps too big, wrong bore finish for ring type etc.

[eschaider]

Where abouts in NorCal are you, Tortuga?


Ed

[tortuga]

Alameda

[bobcowan]

Originally Posted by tortuga

How was the compression?

I don't remember what the exact numbers were. But they were all really close to each other. Led me to believe it was the oil rings that didn't seal. On inspection, they all looked fine to me - a shade tree mechanic.

[redmt]

I would run a leak down test first. High compression could be a sign of excess oil on the cylinder walls. It's not uncommon to see oil scraper rings installed incorrectly. If everything on the lower end checks then I would look at the valve seals and the type. You can check for excessive guide wear without pulling the heads.
If your still looking for a top of the line machine shop with real world prices go see Bobby Gaines at Bell and Gaines in Modesto. I've been using him longer than I can remember.
I do have a leak down tester you could borrow.

[tortuga]

1. Ive got one of those motor puller plates that i will bolt down and seal with some rubber to the intake with the carb off,

2. pop the valve covers and release all the intake valve rockers closing all the intake valves, compression was good so i assume these seal,

3. Put a vacuum pump on my brake vac line, with the PCV line plugged (both come off the manifold just below the carb (trick flow R single plane).

Apply vacuum and listen/observe...any really leaky guides should make noise? Should also check for sealed intake manifold gaskets?

Anybody ever tried this or something similar? I would think it will determine if there is a problem topside or with the rings?

I just hate the idea of pulling the engine for logistical/working space/help reasons...Heads no problem.

Steve H

[redmt]

Leak down is simpler, faster and accurate,,,, I think the vacuum test will sound like a calliope plus you won't be able to figure out where the issue is if there is one.

[hauss]

I could be wrong but, back in high school auto class, many years back, I was told add oil to the cylinder and if your compression goes up, it is your rings.Not sure if this will help in your situation ,but I would give it a try.

[redmt]

Originally Posted by hauss

I could be wrong but, back in high school auto class, many years back, I was told add oil to the cylinder and if your compression goes up, it is your rings.Not sure if this will help in your situation ,but I would give it a try.

You are right but adding oil to a cylinder will always make the compression on a good cylinder rise. It's when it doesn't rise there's a problem. Plus if you don't clear the oil out afterwards it has the strong potential for make a REALLY loud noise when you fire it up. It's called hydro locking.

[tortuga]

Originally Posted by hauss

I could be wrong but, back in high school auto class, many years back, I was told add oil to the cylinder and if your compression goes up, it is your rings.Not sure if this will help in your situation ,but I would give it a try.

When i tested the thing (dry) ALL 8 were between 215 and 220 crazy consistent...I have a leak down tester but thats checking a closed combustion chamber for leakage-More specifically the LOCATION of the leakage, usually after a bad compression test no?

The other think is that is doesnt smoke except for a puff when going suddenly WFO from cruise, but i attribute that to the sudden shot of gas?

[olddog]

Often times when oil is running down the valve stems (guides or seals), it will continue to run down for some time after the engine is shut off. Then when restarted, a nice puff of blue belches out the pipes. Also when you pull the intake, you should see oil on top of the valves.

Compression rings (top two) and oil rings (the bottom groove) work totally differently. It is possible to have good compression and the oil rings not work worth a hoot.

[cycleguy55]

Originally Posted by tortuga

Ford racing 427/535
Been eating oil since day 1.
Not a pcv problem, have Walker pcv with catch tank
Replaced intake gaskets half a dozen times
Compression is 215+/- single digit all 8
Replaced all valve guide seals
Plugs look good albeit a little dark

Has to be valve guides?

Question: what’s the best nor cal machine shop to have the heads gone through?

Steve H
SPF 1764

Had similar oil consumption problems with mild 460. I replaced my valve stem seals as well, but that had little effect.

Turns out the root cause was the intake manifold gaskets weren't properly sealed, allowing oil to be sucked from the valley into intake ports. Drain coolant, pull the intake manifold and carefully inspect the gaskets for signs of leakage.

[ERA 626]

valley machine in livermore