new engine start-up problems

[Brian King]

So I think we figured it out.... Ran the compression test and had between 115-125 lbs on every cylinder, EXCEPT for #8. While running the test on that cylinder, the gauge abruptly stopped at 80. Hmmmm. Turns out my gauge hit the #8 exhaust (hit all of them actually, but only bent #8). Dang.
Pulled the intake off and opened #8 intake and blew compressed air through the spark plug hole - I saw a little piece of chingaso fly out, but not sure if that was stuck in the seat or not. I also had not known about shimming flathead valves, so not entirely sure that the #8 intake didn't just need shimming instead of something stuck on the seat.
Pulled the head and both #8 valves and tomorrow I'll replace with 2 new ones.
And I'll check installed height of all valves to see if more shims are in order.
After I put 2 new valves in then back together and we'll try it out. This is the end of a 20 month ground up build with my 16 year old, and he looks to drive it on the Northern CA Reliability Run this Sunday.
Thanks for all your help!

[glennpm]

Good Brian, glad you have found the chingaso problem at last ;-)



Glenn

[Brian King]

I'm back. Even longer story as to what has gone on the last few days, but I'm stuck again and here is the latest:
- Checked installed spring pressure and all is well.
- Put a dial indicator on a piston and turned it over. Found that the ignition is not firing until the piston is on its way DOWN (by about .060).
- Pulled the front end off, the front cover, assuming I had a brain fart and didn't align the dot on the crank gear with the hash mark on the timing gear.
- Dot and hash mark align.
WHAT IN THE HECK AM I MISSING??? It's an Isky Max 1 cam with a stock timing gear. As I recall, the timing gear only goes on one way. And other than the marks aligning, it definitely makes sense - it acts severely retarded. The last time I tried to fire it, I advanced the distributor as far as it would go and it ran for about 30 secs (poorly) instead of the normal 5-10. But with the way it backfires....retarded for sure.
There's no way the distributor could be set up wrong to cause it to be so retarded, is there? I could pull the cam gear and advance it a tooth - with the marks no longer lining up - but that doesn't seem right.

[JSeery]

Probably need to degree the cam and see what is going on.

[40 Deluxe]

1. Have you tried a different condenser or coil? Wouldn't be the first time a new part was defective out of the box.
2. Have you checked EVERY electrical connection including all grounds?
3. Is the point gap still correct?
4. Hook up a timing light and watch the flash when you start the engine. If the spark is cutting out you will see erratic flashes or no flashes.
5. Borrow a carb from a good running engine or try your carb on a good running engine.
6. Could the valve guides be a little tight, causing the valves to be slow to close? I have seen cases where a valve would close at cranking speeds and give a good compression reading, but hang up when running. Is the compression now even on all cylinders?
7. DO NOT assume anything! Check and verify everything! One step at a time, and you'll find the problem.

[flatjack9]

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Cams have been known to be ground wrong. Need to degree the cam. This should always be done with any cam change. I have found cams to be off by as much as 6*.

[Brian King]

I am ordering a new (smaller) degree wheel that I can fit on the front of the crank pulley with the engine in the truck. So degreeing the cam is next.
Extensively went through Bubba's distributor last night and all looks right. The problem is not carburation, it's not the ignition. I KNOW the spark is firing when the piston has begin it's descent, so I'll degree it and go from there.
All other connections appear to be sound and ignition is producing a good spark - just late (retarded). Stay tuned....

[JSeery]

Has anyone ever ran across the slot in the front of the camshaft being mislocated?

[Mart]

Originally Posted by JSeery

Has anyone ever ran across the slot in the front of the camshaft being mislocated?

I have. But not out angularly, it just wasn't offset the correct amount. I trashed two distributors before I found out what was going on. I had to modify the drive tangs on the distributor to suit. Problem is, that dist is now a one off and will not fit on the timing fixture.

Mart.

[Brian King]

Gents, coming back to this thread. Three weeks and I'm still out of answers. I've chased down every rabbit hole I know. Here is what I've done:
- Degree'd the cam to Isky's specs (dead nuts on)
- Had the distributor checked out on a machine (dead nuts on)
It's ignition, not carburation. I've triple checked the wires and the firing order.
If I didn't know better, I'd think the slot on the front of the cam was offset.
Any more suggestions?

[glennpm]

Hi Brain,


When you tested the distributor did it included your cap and rotor? I had trouble a few months back where my 32 started missing intermittently one day and finally quit. I had to get a tow truck ride home. I eventually found that my rotor was the cause. It looks fine with no cracks etc. I had another new rotor put it in and it started and ran beautifully after that.


Glenn

[KiWinUS]

Originally Posted by Brian King

Gents, coming back to this thread. Three weeks and I'm still out of answers. I've chased down every rabbit hole I know. Here is what I've done:
- Degree'd the cam to Isky's specs (dead nuts on)
- Had the distributor checked out on a machine (dead nuts on)
It's ignition, not carburation. I've triple checked the wires and the firing order.
If I didn't know better, I'd think the slot on the front of the cam was offset.
Any more suggestions?

The slot in the front of cam IS OFFSET!!!

[glennpm]

Yeah I think that is very likely too.

[JSeery]

Originally Posted by KiWinUS

The slot in the front of cam IS OFFSET!!!

I thought he was referring to degrees wish. It is offset to the side to index the distributor, of course. I ask the question earlier if anyone has ever run into a cam with the front indexing slot being off in relationship to the cam timing.

[glennpm]

Yes, and I believe Mart said he had run into it ... yes, post #49 above.

[JSeery]

Originally Posted by glennpm

Yes, and I believe Mart said he had run into it ... yes, post #49 above.

Yes, but that was the side to side issue I thought, this question is about indexing to the cam timing.