Compression Numbers from the 62 (3 Viewers)

[Von Hayek]

Steve helped me get some compression numbers on the engine this afternoon before we started to tear it apart to replace the head gasket. The results are not encouraging:

1 - 180
2 - 140
3 - 142
4 - 140
5 - 135
6 - 155

It seems to me I should have higher overall numbers with two being noticeably lower than the others where the gasket problem is. But other than #1, these numbers all seem real low. I am using a cheapo gauge, but still...

Thoughts? Worn rings?

 

[SAS]

Just a thought--is it possible that you have an erroneous reading on #1 ? All the other readings are pretty consistent, meaning within a standard deviation. I'm no expert, of course, having only changed one cylinder head myself. And that was a 4-banger. My numbers were consistent except the single errant cylinder where the gasket had failed.

If it were my truck...I'd just replace the head gasket and run it as is. Then I'd swap in a diesel if/when it dies. Or at least talk about swapping in a diesel for a long time before actually doing it. (flip-off)

 

[Von Hayek]

Don't think I got a bad reading, but who knows -- it's the first time I have ever taken compression readings. But I think that you are right as far as the engine goes no matter what the results are. I'll slap it back together and see how long she lasts.

 

[kulangot]

Did you do the compression test at WOT? (Wide Open Throttle)

You might be surprised how much the numbers can go up.

 

[Von Hayek]

Did you do the compression test at WOT? (Wide Open Throttle)

You might be surprised how much the numbers can go up.

I'm afraid so.

 

[kulangot]

Did you squirt oil in to see if the numbers came up? That tells you if you have bad rings.

While you have the head off, send it to Simon at Tyson's Machine in Sterling for a refresh. Not that expensive and it makes all the difference to have tight valves. He will mangaflux and look for cracks. Well worth doing. Simon is a great guy. My friend Jim took a Rolls Royce motor to him and Simon is so honest that he said it did not need to be rebuilt just a few minor things - even though Jim gave him carte blance to do what ever he needed to. He used to do all of the work for Land Cruiser connection when they still existed - so he is familiar with Cruiser motors.

Always check rebuilt heads with alcohol. Flip it upside down and fill the combustion chambers.

 

[Von Hayek]

Always check rebuilt heads with alcohol. Flip it upside down and fill the combustion chambers.

IPA?

Did not add oil to the cylinders before we got the head off. Underside of the valve cover was all milkshake, which is really weird because that condition was not present when I adjusted the valves in the spring. No overheat since then either.

Head is going off to get checked for warpage and cracks, new seals, and regrind of the valves if necessary. Also has proven an opportune time to change the side-cover gasket.

Looking to get the injectors serviced if I can get them back by next Saturday.

 

[SAS]

Glad to hear that you got it all put back together this weekend, and TRFCSUX says it is running sweetly. Good job! (beer)

 

[Von Hayek]

Yeah, I must say it is a pretty big difference. Between getting the valves & seats ground, the injectors cleaned, and the gasket sealed, it is running so much more smoothly and dare I say with a tad more power. Idles like a champ. A lot of work, but well worth it and it had to be done.