Engine has about 1500 - 2000 miles. There is a thich, heavy black oily residue in the #4 intake and exhaust port. The top of the #4 piston has a white/grey residue on it.

Any thoughts as to what could have caused this? Would it likely be from the heads or the block? Transmission modulator or PVC? I was running a 1965 GM #461 intake.

Is the carbon build-up on top of the pistons normal? What would have caused it?

Pass Side (#4 is the cylinder that had the black oily reside in intake and exhaust port)
http://pic50.picturetrail.com/VOL432/649897/1911581/282214192.jpg

Driver side
http://pic50.picturetrail.com/VOL432/649897/1911581/282214194.jpg

BTW, this 383 engine ran about 20* warmer than the 396 SB that replaced it. If the short block is still healthy, I would like to put it back in my truck.

TIA, Wes

Not sure about residue on the piston, but pistons that are clean around the outside edge usually mean that oil is getting by the rings, doesnt look very good for low miles.

Bob, thanks for the feedback... I was hoping to put it back in my truck and not touch it for another 10 - 15 years. Maybe I'll get lucky and be able to get by with honing it and new rings.

Do you have any idea what could have caused the black oily residue in the #4 intake and exhaust ports?

Thanks again,

Wes

Did you check all the valve seals to make sure you didn't tear one on installation? That and an intake leak are most likely the culprits.

Gren69Chvl, thanks for the input. I haven't checked the seals yet. The gunk in the intake tract was pretty thick. If it was a gasket issue, would it be sucking that much oil in a relative short time?

If the ring seal is bad as Bob suggested, is there any chance of them re-seating, or, will it need honed and new rings at at a minimum?

Where exactly does the PCV hose attach to the manifold?

Is the black residue also present in the port in the manifold? Or does it start at the port in the head?

Was the engine using oil that know of?

Those pistons look pretty nasty to me for a low-mileage engine. I'd use a 400 grit ball hone on it and install a new set of of Sealed Power single moly rings.

Tom, when I first broke in the engine, the PVC and the trans modulator line were hooked to the vacuum fitting on the side of an 1850 600 Holley. I later switched to a 3310 Holley and the PVC went to the back of the carb and the modulator went to a fitting in the intake.

On the intake manifold, there was a slight residue in the number 4 port, but it was very thin and a caramel color. Where as the intake and exhaust ports of the heads were thick, black and oily.

The engine didn't seem to be using a lot of oil. When the engine was first fired, we drove the car to Vegas with the Anti Tour, about 600 miles round trip. We also made a couple 1/4 mile passes. During the trip, the engine used about 3/4 quart of oil, but I also lost some oil when I hot lashed the valves.

Looks like I need to tear it down. Hopefully the crank and rod bearings are OK.

Thanks again for the help and the confirmation of what Bob said. Wes

On the intake manifold, there was a slight residue in the number 4 port, but it was very thin and a caramel color. Where as the intake and exhaust ports of the heads were thick, black and oily.

Looks like I need to tear it down. Hopefully the crank and rod bearings are OK.

Thanks again for the help and the confirmation of what Bob said. Wes

Why tear it down? It sounds to me as if you were sucking oil from the lifter valley. How does the intake fit?

wildman, Thank you for the input. I haven't laid a straight edge to the intake yet, but it is a stock, 1965 Chevy aluminum intake. I'll do this before re-using the intake.

I only had an oily residue in the #4 intake and exhaust ports. However, there is a lot of carbon residue on the tops of several pistons.


I can't really think of anything I did to keep the rings from sealing, except for the first night at the track, when a float sank and dumped gas all over the intake at the track. At this point there was probably 400 - 450 miles on the engine. Afterward, I drove home to L.A. from Vegas, and the oil may have been more gas diluted than I thought...

Hopefully upon teardown, it is just a matter of honing it, and adding rings and bearings.

Just for info sake -you didn't use the FelPro metal intake gasket with the blue coating? These will not seal an alum intake to iron heads. Ford small blocks are notoroius for intake leaks - especially when using the 351W heads - the port area at the bottum of the head is real narrow for sealing. For hard to seal intake/head combos, I found the only gasket that works are the good old standard Mr. Gasket paper gaskets sprayed liberally with multiple coats of High Tack and RTV at the water jackets.

GRN69CHV, I used a Felpro 1205. My heads are opened up to the 1205 Gasket, but the intake hasn't been ported. I used RTV at the end seals and around the water jackets, but I didn't use any high tack on the gaskets.

That said, I will be sure to check the coverage between the intake and a 1205 gasket.

Wes

Are those the gaskets with the built-in little silicone beads around the intake ports? If not, try a set of those. Where the heads ever surfaced and/or the block ever decked? If so, you might have created some intake sealing issues.

When you pull the intake, you should be able to see how well, or not, the manifold sealed at the bottom of the gaskets around the intake ports. The 400 in my truck was sucking oil there once and when I pulled the manifold it was clear that the bottom of the gaskets were oil soaked and had clearly not been compressed by the install of the manifold.

With an old 461 manifold you also need to be careful not to over tighten the manifold bolts or you can break the edges off the manifold. This can be compounded by having had the heads or block surfaced but not to have had the manifold cut down too. (Depends on how much you may have taken off the heads or block though.) Don't let the desire to clamp that manifold down for a good seal make you over torque the bolts!

Also, did you use the end gaskets under the manifold? You might have better luck leaving them out and replacing them with a bead of silicone so the manifold can seat down a little further to the block and heads thus providing a better intake gasket seal.

could it have been sucking some ATF from the modulator hose?

Yes, they are the gaskets with the silicone bead on the intake ports.

Rich, the block hasn't been decked. The gaskets are the same ones shown by wildman. I'm not sure about the heads. The intake gaskets broke as they were being removed. I'll check the pieces for oil soaking, but it didn't satnd out when I pulled the intake. I used black RTV to seal the front and rear of the intakes.

Smittyocat, I thought of that. I will need to check the modulator hose and see if there is any fluid present.

I'm going to look into it somemore this weekend and see what I can find.

Thanks again,

Wes

Usually an ATF issue will smoke like heck, but is more likely to clean out the carbon, rather than deposit it. If there are no tale tell signs of gasket or intake valve seal failure, then start your tear down by pulling that slug first. Any number of things could be the culprit, something as stupid as all of the ring gaps being aligned.

I knew a guy that would go on and on about how his SBF was "blueprinted". My rings are all file fit..... Yeah, by a retard. Each had a ridge (snag) on the end that dug deep vertical grooves in the cylinder walls. The 007 Maverick, complete with smoke screen.

I knew a guy that would go on and on about how his SBF was "blueprinted". My rings are all file fit..... Yeah, by a retard.

That cracked me up!!

Rowdy,

I hope to get into the engine this weekend. It makes sense what you said about the atf, because you can pour it down a carb to break the carbon up. BTW, this was the engine that had all the valvetrain noise when we followed you home from the track.

Wes