Engine Trouble

[Steves46]

My 30 Coupe has been running outstanding over the past 2 years until last weekend while driving on the way home. After flawless operation for 10 miles, no sooner than shifting 1st to 2nd gear after a stop sign, out of nowhere the Engine became louder like a tractor and had trouble going 25 to 30 mph. I also noticed whitish gray smoke coming from the tail pipes from acceleration.

I am running a Snyders 5:5 high compression head, Ansen single down draft intake manifold with an English Stromberg 97, and tube headers with straight pipes to the back. The distributor is stock and is a 12V system. Fortunately this happened less than a mile from my house so I limped home. Upon removing the spark plugs, 1 & 2 cylinders looked good however 3 & 4 had oil on the electrodes. I have not taken a compression test but wondering what could have let go to cause the poor performance and smoke.?

Although I am running straight pipes, whatever this problem is, the engine & exhaust sounds much louder. The oil looked good and not milky. I am wondering if the piston rings gave out or possibly the one or 2 of the valves? Appreciate any other suggested areas to troubleshoot. The whole ordeal is odd for there was no warning or any indications of a problem prior to this episode.

[Synchro909]

I also noticed whitish gray smoke coming from the tail pipes from acceleration.
Are you sure what you saw was smoke and not steam? I suspect you have a head gasket problem that is allowing coolant into the cylinder/s. What did the "smoke" smell like?

[Steves46]

It was smoke coming from the tailpipe. When I parked it, I accelerated and even more smoke came out. I am concerned regarding the oil that I found on spark plugs 3 and 4.

[nkaminar]

A head gasket that blows between 3 and 4 cylinder will not put water in the oil but will reduce the compression and cause the car to run poorly. The oil on the plugs may be because they are not firing correctly because of the poor compression. As Synchro said the smoke may be coming from the coolant. It can produce a whitish grey smoke.

Low compression can also be caused by a broken valve and this can cause oil to be sucked into the cylinders and expelled out the exhaust pipe where it burns causing the smoke.

Test the compression by turning the engine over with the hand crank. If you get low compression in the back two cylinders or one of the two back cylinders, you may be able to see what is going on with the valves with a bore scope or dental mirror down the spark plug holes.

I will predict that the head will have to come off.

Although not unheard of, it is not likely that you have a broken piston ring.

[katy]

Do a compression test, post the results.

[1crosscut]

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Sounding like a head gasket failure. Hopefully that is what it is as it is a straight forward fix.

Before you remove the head check the torque value of each of the studs starting at 35 lbs. and working up from there to 55. Doing this will let you know what the torque value was on each of the studs. If you find that you had a low torque value on some or all of them it could have been the cause of the failure. If that is the case you can be a bit more comfortable with just replacing the head gasket. If you take it off without checking them you loose a valuable bit of information.

[Big hammer]

Originally Posted by katy

Do a compression test, post the results.

And due a leak down test it will tell more what’s going on!

[Steves46]

Update. I should have used a better flashlight for when I looked again down all the cylinders, I saw very small amount of water so I am in the process of removing the head and ordering a new head gasket from Synders. Now if I can get my distributor unstuck. I am letting it soak with PB blaster.

[Richard Knight]

Have your head checked for flatness. May need to be surfaced. Not belt sanded. Use plain water, retorque at least three times.

[Steves46]

I certainly will. Honestly I’m disappointed that the gasket failed for I have only had the 5.5:1 high compression head for only two years.

[Synchro909]

Originally Posted by Steves46

I certainly will. Honestly I’m disappointed that the gasket failed for I have only had the 5.5:1 high compression head for only two years.

How many times and at what intervals have you checked the tension on the head studs over those 2 years?

[Y-Blockhead]

Originally Posted by Synchro909

How many times and at what intervals have you checked the tension on the head studs over those 2 years?

Great question. I make re-torquing my head part of the oil change routine. While waiting for the oil to drain, I check the head.

[Steves46]

Well it looks like I learned a lesson. I have not checked the torque since installation. Upon checking a couple of additional times, do these work themselves loose to where you would need to check every 500 to 1000 miles?

[katy]

Originally Posted by Steves46

Well it looks like I learned a lesson. I have not checked the torque since installation. Upon checking a couple of additional times, do these work themselves loose to where you would need to check every 500 to 1000 miles?

The gasket compresses.

[Synchro909]

Has this engine been over heated? If a Model A engine gets too hot, it is in grave danger of cracking, usually from #3 or 4 exhaust valve to the cylinder. Over time (not much time), the crack extends down the cylinder and further into the exhaust port. Eventually, it reaches the water jacket and coolant is able to enter the cylinder. I hope that is not the problem here because the only 100% sure fix is another block, crack tested of course.

[Steves46]

No overheating at all so I am hoping it’s just the gasket. The distributor is still stiff but got a slight move this evening. Sprayed more PB blaster and will try to get it removed hopefully tomorrow.

[nkaminar]

I have had the best luck with the graphite gasket from the Best company. The parts dealers have these. I also use the copper spray gasket cement.

Torque the head when the block is at room temperature. Torque it after the first warm up of the engine then at 100 and 500 miles and then every 6 months or so. Let it sit over night after a run to get the block to a uniform room temperature.

The flatness of the head can be gauged by a sheet of flat glass with some blueing on it. The blueing will come off at the high spots and the low spots will not have any color. Or, take it to a machine shop. If they deck it, have them re cut the pockets for the pistons.

Small imperfections in the head or block can be filled with JB Weld after careful cleaning with acetone or lacquer thinner. Dress the JB Weld to the surrounding surface with some fine wet and dry paper wrapped around a flat object.

[katy]

Originally Posted by Steves46

No overheating at all so I am hoping it’s just the gasket. The distributor is still stiff but got a slight move this evening. Sprayed more PB blaster and will try to get it removed hopefully tomorrow.

W/the distributor still in the head, remove the head, turn it upside down and pour some of your favorite penetrating oil down around the distributor. While that's soaking you can clean the gasket surfaces of the head and block.

FWIW, I prefer the plain copper clad head gasket w/1 or 2 coats of spray aluminum paint left to dry before installing. Never had a leaker using this method.

[Steves46]

The Les Andrews book recommends removing the 2 water neck studs; is this necessary or can I get by without risking breaking a stud(s)?

[Herb Concord Ca]

Yes.