I'am looking into buying a block with the rotating assembly, it was rebuilt 10,000 miles ago, it has the stock bore. I was told by the owner it has 149-150 compression all accross, except number 6, since the valve wasnt sitting corectly (60psi). Does 149-150 seem like a good compression? He was also using a metal head gasket.
Question on compression on 10K mile build
- Thread starter Angry7M
- Start date
Consistancy is more important that number.
Mine where in the 150 range as well, and the block is used...
Mine where in the 150 range as well, and the block is used...
Well, they kinda should be higher given mine is a very warn shortblock...
Are you sure it was the valve? (if you do a leakdown test you'll hear the air leaking out of the port if the manifolds are off)
Are you sure it was the valve? (if you do a leakdown test you'll hear the air leaking out of the port if the manifolds are off)
please elaborate on the number 6 and the valve not sitting properly? Needs to be shimmed properly?burnt valve?
Yeah I thought the numbers seems a little on the low side, but i dont know. The block is suppose to have new toyota bearings and it was decked. Also maybe it was his metal head gasket that lowered his compression? And the block is not on the car, and its headless lol, so no leak down tests can be made.
According to him, the machine shop told him about the valve not sittling correctly. And that was the cause of the low compression, i believe it had 60 psi on the 6th cylinder.
According to him, the machine shop told him about the valve not sittling correctly. And that was the cause of the low compression, i believe it had 60 psi on the 6th cylinder.
is this for a turbo or NA. you didnt say, and its diffrent on the NA. the compression should be higher than the turbo.
Sounds like the guy doesn't seem to know for sure what he is talking about unless he told you there is an issue with the 6th cylinder(not that the valve isn't sitting "right") figure out what he means by that, because you may be needing to do valve work, so put that into the equation as well. They should all be consistent with each other any moderation in compression is an issue, to me anything more than about 14psi variation is a problem.
If he did the compression test correct with the car warm and throttle plate open something is going to need replaced in that 6th cylinder valve guide, valve, valve seat issue, rings. Try to get some clarification on that for your sake. Sounds though if the machine shop is correct which I wouldn't doubt the valve isn't seating correctly thus loosing compression, you'll probably be looking at a valve job/possible valve if it's bent.
If he did the compression test correct with the car warm and throttle plate open something is going to need replaced in that 6th cylinder valve guide, valve, valve seat issue, rings. Try to get some clarification on that for your sake. Sounds though if the machine shop is correct which I wouldn't doubt the valve isn't seating correctly thus loosing compression, you'll probably be looking at a valve job/possible valve if it's bent.
and if it is the valve, pour water into that combustion chamber and see if it leaks out through the port.
but if its just one or two valves thats cheap and easy to do...
but if its just one or two valves thats cheap and easy to do...
Guys he is only selliing me the block, i dont want the head, I was planning on using the one on my engine.
BTW how much does it cost to replaced bearings and rings? I was taking a look at driftmotion and the have piston rings for 60 dlls, that seems to cheap. Is that what they usually cost? Thanks
BTW how much does it cost to replaced bearings and rings? I was taking a look at driftmotion and the have piston rings for 60 dlls, that seems to cheap. Is that what they usually cost? Thanks
rings are cheap, its normally the labor that is espensive... and if you re-ring the engine, and put in new bearings, obvisouly have them both checked. Bearings are cheap, there like 125? on driftmotion for the clevite77's... and rings arent much either, so if you dont care about the head, then i would say go for it. especially if your getting it for less than say... $300...
You HAVE to have the cylinders honed if you're redoing the rings, or they won't break in properly.
Bearings and rings are cheap, it's the work required for them that gets expensive...
Bearings and rings are cheap, it's the work required for them that gets expensive...
i wouldnt buy a motor from someone unless i was at least going to have it checked out by a reputable machine shop with the proper tools and experience.
this deal sounds kinda shady so i would get it checked out regardless. i wouldnt take a chance if your planning on slapping on your head and dropping the motor in as is.
not only that you should have the deck and head resurfaced to the proper RA if you plan on using a MHG
-pete
this deal sounds kinda shady so i would get it checked out regardless. i wouldnt take a chance if your planning on slapping on your head and dropping the motor in as is.
not only that you should have the deck and head resurfaced to the proper RA if you plan on using a MHG
-pete