No spark / running out of ideas

Jimscorpsewhale wrote: Well I checked the gauge against my air compressor and it was close. At worst it’s a slight underestimate. Dry I’m getting close to 80 in all of the cylinders except #8 this time. Not sure it read 85 last time and this time it was like 100. After the oil they all get over 100 except #4 is at 90. Most get close to 110. Not sure how to square it in my head. When i drove it seemed to have decent midrange power and it started right up.... Anything else I need to check?

So I’ll go ahead with the leak down. I have a question. When you read about the automotive version you put the car in gear so the engine doesn’t turn over as you add the air.   If i have the boat in neutral when I add the air then the engine may rotatate and the valve may open and create “leak”. Should I put it in forward or reverse? Is the a better way to prevent rotation?

The engine isn’t that hard to turn by hand so I’m pretty sure if I put 80psi on it then it’s going to turn.

Does anyone have any suggestion about how to keep it from rotating?

I guess if i can’t keep it from turning then I could pull the rods and the valves will be closed for sure. Then there wouldn’t be any question about wether the leak would be related to the valve being partially open.

I agree and as the thread has a run over quite a long time I can recap.

I bought the boat in November. At the time I picked it up it ran. Started relatively easily and while I didn’t really drive aggressively the power seemed fine through the midrange.

I bought and edelbrock performer intake and iron gt40p heads.

After the install I went to time the boat. I didn’t get flash from the timing light. The distributor cap was in pretty bad shape so I swapped it. I still didn’t have a flash and then replaced the distributor with one from DUI. It ended up being the digital timing light. An analog light and an inline checker confirmed the spark. I did replace the starter as well. There was a question at that point whether I was 180 degrees out of time. I pulled the valve cover to confirm the timing and found water in the oil.

I pulled the heads and intake. Cleaned everything up put new gaskets down.

The pushrods are the same the lifters are new. Nothing else has changed.

Currently the timing is correct, I have a spark, there is fuel delivery from the carb.

The compression is down. I plan to do the leak down.

The balancer and the distributor both spin CC

Thanks Gary. I’ll start with the number one cylinder. I assume that if I need to test the other cylinders i need to get them up as well...
Although what’s plaguing #1 is probably the same on the others.

New lifters and old camshaft...well ask 10 gear-heads and get 15 different answers.  I know I wouldn’t do it — at a minimum you should consider a cam break-in process once you get the gremlins worked out.  

As far as the head gaskets I used a new set after the oil fiasco. I cleaned the surface of the block, used the dowels to line up the gasket, made sure the front tab was in the front and torqued it in the specified pattern. It was three steps with a final torque of 90 is believe.

So I used engine assembly lube on the lifters. Also before I put the distributor in and the valve covers on I used a speed wrench to pump up the oil until it went up through all the rods into the rockers... I hope this is what a pre-lube is.

I set the tension on the rockers prior to doing the pump up.

When it finally starts for you a camshaft break in will be absolutely necessary.  You need 2,000 RPM to get the new lifters broken in to spinning in your lifter bores.  If they don't spin the camshaft will go flat.  This needs to be done as soon as the engine starts and you quickly verify that you have good oil pressure, your cooling system is not leaking and it is safe to spin up to 2,000 RPM.  Keep it there for 20-30 minutes then it is good for the life of the engine.

In my old job I bet I saw 25 different piston failures caused by someone mis using starting fluid.  If you use to much,  or use it badly things break quickly.  I even saw one engine with the intake manifold blown off.

Jim, I’ve heard some good things about Michigan Motorz

https://www.michiganmotorz.com/

I think at long last we can see that 80 psi we a real compression figure and of course that’s just not enough to get it running.

Seems hard to imagine it ran before and seemed to be running decently.

I certainly don't profess to know the details of leakdown versus compression testing but it strikes me as a little strange that an engine that ran before head work and does not run now needs a new bottom end. In the same situation, I'd be more suspicious of the items I recently changed....

Yeah if there are other pieces unfortunately I’m not aware of them either....   if any one wants to come get the block for a post mortem exam I’ll be happy to give it up.