[Shockwave78]

Originally Posted by Gach

Question, how was the motor running before you put new rings in and made cam change ? Just wondering if you where just making cam change what made you decide to hone and put new rings in.

It ran fine, but it pushed oil into the air cleaner from the valve cover breather. The cam and rings were planned before the engine came apart.

[grandam1979]

Originally Posted by Shockwave78

It ran fine, but it pushed oil into the air cleaner from the valve cover breather. The cam and rings were planned before the engine came apart.

Sounds like it just had bad blow by time for rings at minimum.

[Gach]

I’d say just honing and putting new rings in plus adding more cam, which would have created more power. Didn’t work and won’t in doing it all over again. I would bit the bullet, and go .030 with new pistons and rings, also would put some good valve seals in there and get rid of the O’rings. Or else you’ll be chasing your tail.

[Gach]

The new cam created more dynamic pressure. ( compression) just adding to your issues and new rings didn’t really do much. I’m thinking what ever your piston to wall clearances were or are now isn’t good, new rings may of help temporarily. Also thinking if all was ok initially it would’ve been short lived. Its just not sealing up, weather is the rings or valve seals, or A combination of both….just honing and putting in new rings is like a coin toss.

[Shockwave78]

Originally Posted by Gach

I’d say just honing and putting new rings in plus adding more cam, which would have created more power. Didn’t work and won’t in doing it all over again. I would bit the bullet, and go .030 with new pistons and rings, also would put some good valve seals in there and get rid of the O’rings. Or else you’ll be chasing your tail.

That would be ideal of course, but it's not like I'm the only person to do a cam swap, there is something else going on, it's just a matter of finding it. The other big factor is I start school on the 21st and it's a thousand mile drive back. I don't really have time for the machine shop on this schedule. I'm kicking around the idea of hand polishing the journals and putting new bearings in. I can't see any reason why a lightly grooved crank would pose a problem as long as there are not any bits sticking out and the clearances are good.

[Shockwave78]

Originally Posted by Gach

The new cam created more dynamic pressure. ( compression) just adding to your issues and new rings didn’t really do much. I’m thinking what ever your piston to wall clearances were or are now isn’t good, new rings may of help temporarily. Also thinking if all was ok initially it would’ve been short lived. Its just not sealing up, weather is the rings or valve seals, or A combination of both….just honing and putting in new rings is like a coin toss.

Before I tore the engine apart it was a daily for about a year, and didnt have any issues so I don't know how "short lived" it would have been. The car has done multiple cross country trips.

[Gach]

Originally Posted by Shockwave78

That would be ideal of course, but it's not like I'm the only person to do a cam swap, there is something else going on, it's just a matter of finding it. The other big factor is I start school on the 21st and it's a thousand mile drive back. I don't really have time for the machine shop on this schedule. I'm kicking around the idea of hand polishing the journals and putting new bearings in. I can't see any reason why a lightly grooved crank would pose a problem as long as there are not any bits sticking out and the clearances are good.

Understand..hey you can give it a shot. I don’t know how to pinpoint what the issue is now….. as it stands.

[Gach]

Originally Posted by Shockwave78

It ran fine, but it pushed oil into the air cleaner from the valve cover breather. The cam and rings were planned before the engine came apart.

Blowing oil in to air cleaner, from valve cover breather… that’s usually blow by. did you replace the PVC valve at anytime. I don’t know I’m lost on what else to tell you. Good luck.

[Stan Weiss]

Originally Posted by Shockwave78

Outer 2 on both sides are wet with oil/gas inner two on Both are dry

I am still trying to understand what is happening. Do the intake ports match the exhaust ports as far as what is wet and what is dry?

Stan

[Shockwave78]

Originally Posted by Stan Weiss

I am still trying to understand what is happening. Do the intake ports match the exhaust ports as far as what is wet and what is dry?

Stan

no, all intake runners are wet with oil, I think it was getting oil through the pcv system. the pcv port on the carb did have some oil in it. The inboard exhaust ports do have the crossover on the intake, maybe that has something to do with it

[johnta1]

Still think the (intakes at least?) valves were not closing fully, and when coming up on compression it was blowing back into the intake.

Probably not a lot of leakage but any amount will cause this?

[Gach]

Originally Posted by johnta1

Still think the (intakes at least?) valves were not closing fully, and when coming up on compression it was blowing back into the intake.

Probably not a lot of leakage but any amount will cause this?

Possible ?

[slowbird]

Originally Posted by johnta1

Still think the (intakes at least?) valves were not closing fully, and when coming up on compression it was blowing back into the intake.

Probably not a lot of leakage but any amount will cause this?

Seems unlikely to hang a valve open enough to do what you're saying and still pump 150psi.

[steve25]

Any intake valves that where not closing properly, yet the cylinders firing would have made for back fires being heard out the Carb, especially when you put your foot in it,BTDT!

Did the op have plugs that where not firing? I forget.

The one major thing here that will have many different repercussions is that for whatever reason the amount of run time on the motor in its poor state was enough to get the engine oil to smell of fuel, so this was either due to 1) cylinders not firing. 2) a Carb problem. 3) or both combined!

Also low vacuum in and of itself would have made for a rich condition.

Diluted engine oil combined with blowby will make a mess of things, I have seen this in many a high mileage SBC motors that should have been rebuilt the right way, that there owners just re-ringed and stuff in a 250 duration Cam and a 850 Carb while the delusion of then having a 11 second car.

[Gary H]

I'll say it again. The most plausible explanation is that the timing chain was installed wrong, using the wrong mark on the multiple keyway crank gear. Easy mistake to use the mark over the crank keyway rather than the correct one. It will retard the camshaft and cause a big loss in power. Seen it multiple times on customer's cars.

[Stan Weiss]

Originally Posted by Gary H

I'll say it again. The most plausible explanation is that the timing chain was installed wrong, using the wrong mark on the multiple keyway crank gear. Easy mistake to use the mark over the crank keyway rather than the correct one. It will retard the camshaft and cause a big loss in power. Seen it multiple times on customer's cars.

Gary,
The only way that cam could show the cranking compression it did, in that engine, and the cam was well retarded, is if his CR was 9.0:1 or higher.

Stan

[Stan Weiss]

Originally Posted by steve25

Any intake valves that where not closing properly, yet the cylinders firing would have made for back fires being heard out the Carb, especially when you put your foot in it,BTDT!

Did the op have plugs that where not firing? I forget.

The one major thing here that will have many different repercussions is that for whatever reason the amount of run time on the motor in its poor state was enough to get the engine oil to smell of fuel, so this was either due to 1) cylinders not firing. 2) a Carb problem. 3) or both combined!

Also low vacuum in and of itself would have made for a rich condition.

Diluted engine oil combined with blowby will make a mess of things, I have seen this in many a high mileage SBC motors that should have been rebuilt the right way, that there owners just re-ringed and stuff in a 250 duration Cam and a 850 Carb while the delusion of then having a 11 second car.

Steve,
I guess I look at what is going on here totally different than you do.

When first put together it had 15" of vacuum. Which should have not caused any problems.

It is a 400 ci with a 270/277 Adv 210/221 @ 0.050" cam. I am sure no delusion of even having a 12 second car

I am still not sure that it did have a ring seal problem.

Stan

[Shockwave78]

Originally Posted by steve25

Any intake valves that where not closing properly, yet the cylinders firing would have made for back fires being heard out the Carb, especially when you put your foot in it,BTDT!

Did the op have plugs that where not firing? I forget.

The one major thing here that will have many different repercussions is that for whatever reason the amount of run time on the motor in its poor state was enough to get the engine oil to smell of fuel, so this was either due to 1) cylinders not firing. 2) a Carb problem. 3) or both combined!

Also low vacuum in and of itself would have made for a rich condition.

Diluted engine oil combined with blowby will make a mess of things, I have seen this in many a high mileage SBC motors that should have been rebuilt the right way, that there owners just re-ringed and stuff in a 250 duration Cam and a 850 Carb while the delusion of then having a 11 second car.

it was firing on all 8, I checked the cam timing, it was installed correctly, and the new timing set is cut exactly the same as the old stock one, so I don't believe cam timing is the issue. I don't know that the piston rings sealing is/was the issue either, because of the compression it had, and the cylinders are no more scored now than they were when I first took the engine apart. The fuel in the oil was definitely a carb issue, and that has been fixed.