head resurfacing and timing, techs wanted

[BAlbertiX]

in the garage

should I feel resistance through TDC cranking by hand?

[BAlbertiX]

timing

Some updates >








Head and gasket in, timing TDC and clearances .010, got fuel and spark.

Before first start, I figured I'd hand crank the engine a few times to verify timing.

I know there's resistance on the compression strokes, but it feels more than usual. I can rotate through these points, but they feel much tougher than usual. The head was resurfaced twice in its lifetime and is down anywhere from .006" to .010" total. I took .003" off the head this last rebuild. I'm worried about interference. How much room do I have to play with?

Can I advance or retard timing on the cam to correct for potential interference?

[BAlbertiX]

....I bought a set Here for ~$10/ea, and I'm very happy with them.

Great stuff Northern. Thanks for the heads up, for $5ea I'll be shipping them out to Cali this weekend.

[Northern]

I'd start by replacing your fuel flex hoses between the tank/hard lines, and in the engine bay. While you're there, replace the fuel filter.

There are numerous people on r3v who will clean/flowmatch injectors for much less than $40ea.

I bought a set Here for ~$10/ea, and I'm very happy with them.

[BAlbertiX]

I have this thing about flow- testing injectors.

If one or 2 are restricted, those cylinders will run lean,
the others will run rich, and things like this can happen.

Not saying it's your problem, just that it's good to test for...

fwiw
t

The engine did overheat and stall out on the highway due to a fast coolant leak approximately a year and a half ago. Once it cooled, I replaced the hose, filled the reservoir and went on with my life. However, I think this was the start of it's slow death. Given the burn marks were on the front end of the gasket, and the front of the head was out of flat by .003, leads me to believe overheating caused this.

On the other hand, I DO want to be sure my fuel system is strong. My budget is tight, and would rather stay away from the sea-foam / injector cleaner, over the counter stuff. While I've got the manifold off, how would you suggest I test and clean? Eeuroparts sells rebuilt injectors for $40ea... Side note: Fuel rail, fpr, and filter are new.

[mpowerful]

^true

[TobyB]

I have this thing about flow- testing injectors.

If one or 2 are restricted, those cylinders will run lean,
the others will run rich, and things like this can happen.

Not saying it's your problem, just that it's good to test for...

fwiw
t

[Cabriolet]

Thanks dnguyen, 10W-40 it is.

10-40 winter, 20-50 summer

[BAlbertiX]

Glad you found the problem. BTW, 5W30 is way too thin for this engine.

Thanks dnguyen, 10W-40 it is.

[dnguyen1963]

Glad you found the problem. BTW, 5W30 is way too thin for this engine.

[BAlbertiX]

Winner winner chicken dinner Cabriolet. The break would explain the hesitation sound on start and lack of oil in coolant and vice versa. Looks like a overheat, time to deck the head.

[BAlbertiX]

you have a blown head or headgasket. just pull the head. if you have the money rebuild the engine. ($2500). rebuilding an m20 makes it a lot of fun again. otherwise, if you dont have the money, just get the head checked and rebuilt. Then slap it back on. (<$1000). if you dont have the tools ask a fellow r3v'er to help you.

I'm crossing my fingers it's head related. The block was 50k new when I bought it 3 years ago. I know the rockers wear over time and the eccentrics need tightening, but any chance it's common for the set screws to let go?

It might be worth inspecting every rocker arm and shaft retainers for cracks?

[Cabriolet]

you have a blown head or headgasket. just pull the head. if you have the money rebuild the engine. ($2500). rebuilding an m20 makes it a lot of fun again. otherwise, if you dont have the money, just get the head checked and rebuilt. Then slap it back on. (<$1000). if you dont have the tools ask a fellow r3v'er to help you.

[BAlbertiX]

well you have serious issue per your compression test, normal should be in the 160-170psi range (is that warm? cold ?,when was last valve adjust? ) you only want to see about 10% difference across all cylinders. try add some oil into each cyl (use a small oil can with some small tubing inserted into sparkplug hole and give each a couple squirts ) crank over a few times with plugs out and then redo your compression test if numbers improve on low cylinders you have ring/piston issues if not most likey valve sealing issues, and a leakdown test is needed next .

get rid of those autocrap sparkplugs to ,known to cause misfire issue themselves

It was a cold test. I ran the engine for a minute or two, but the engine was definitely not at temp.

Last valve adjustment was last summer, gapped to .010".

I will redo the compression test this week with your suggestions. If that does not prove anything, I will find an air compressor for the leakdown test.

For what it's worth, and I will add this above, the engine started doing this out of nowhere just over a month ago while I was driving home after work. The only difference between this day the ones previous, was that it was an unseasonably warm day at the tail end of winter.

[jlevie]

+, the compression test points to the cause. A leak down test will tell if it is the rings or the head.