those are great, just as expected. describe the smoking cause valve stem seals most likely culprit
Compression Results
Well I finally did a compression test on the 1991 RC 318. The truck smokes and has over 200k miles on it so I wanted to get a baseline on it since I've had it. I let the engine warm up first then unplugged distributer and power to fuel pump. I removed 1 plug at a time and had someone crank it until needle quit climbing on the guage. Here are my results in numerical order:
1-155psi
2-150psi
3-155psi
4-160psi
5-155psi
6-160psi
7-160psi
8-152psi
My FSM says the compression ratio is 9.1:1.
Would you say my readings are in line with that? Based on these results do you think this verifies that the smoking is most likely valve seals?
Thanks!
1-155psi
2-150psi
3-155psi
4-160psi
5-155psi
6-160psi
7-160psi
8-152psi
My FSM says the compression ratio is 9.1:1.
Would you say my readings are in line with that? Based on these results do you think this verifies that the smoking is most likely valve seals?
Thanks!
1 - 20 of 24 Posts
I think the test is done with all plugs out. Anyways those numbers are fine!
Bucky
Bucky
I've heard of it being done both ways but I didn't want to route plug wires so I did one at a time. Hopefully the results aren't skewed!I think the test is done with all plugs out. Anyways those numbers are fine!
Bucky
It'll smoke at startup and take off. Fine going down the road or at least very thin smoke. It may start again sitting at a long red light, a puff at take off and then clear again.those are great, just as expected. describe the smoking cause valve stem seals most likely culprit
Sounds like valve seals. Those compression numbers are decent and realitivly even across the board which is what you want to see. A couple were down a bit in comparison but that could be because of a bit of carbon build-up.
My initial test on cylinder 1 resulted in 129psi on a cold engine. The engine heated up as I cranked it throughout the test and I saw the numbers climbed, so I thought a more accurate test would be to do the entire test on a warm engine; hence the higher readings. If I did the test with a cold engine I would expect that each cylinder would be around 130psi?I'd call the numbers way high. 9-1 at 30 inches is about 130 psi, adjust for altitude. Can't imagine it running well with enough carbon on the pistons to give to 10-1.
View attachment 639458
I've always done it on a cold motor because hot exhaust and spark plugs is no fun. 130 is ball park what I get on smog motors.
Holy Crap! I didn't even know you could check compression on a motor! Is that in the Tesla Manual on how to do that? 😁😆😅😂🤣I've always done it on a cold motor because hot exhaust and spark plugs is no fun. 130 is ball park what I get on smog motors.
What I don't get is why they call it "motorsports". Lol 🤔Holy Crap! I didn't even know you could check compression on a motor! Is that in the Tesla Manual on how to do that? 😁😆😅😂🤣
Doesn’t an engine need electricity or what we call spark to run? Difference doesn’t matter lol you know what he meant
They were ahead of their time. lolWhat I don't get is why they call it "motorsports". Lol 🤔
In the world today, that terminology matters. Just wait til Hydrogen comes out. What the hell is that going to be called? lolDoesn’t an engine need electricity or what we call spark to run? Difference doesn’t matter lol you know what he meant
It does in fact take a motor to start our engines as SuperB pointed out one time. lolDoesn’t an engine need electricity or what we call spark to run? Difference doesn’t matter lol you know what he meant
If anything doing it one plug at a time would show lower readings.I've heard of it being done both ways but I didn't want to route plug wires so I did one at a time. Hopefully the results aren't skewed!
Bucky
Details, details, details.Holy Crap! I didn't even know you could check compression on a motor! Is that in the Tesla Manual on how to do that? 😁😆😅😂🤣
Hindenburg.In the world today, that terminology matters. Just wait til Hydrogen comes out. What the hell is that going to be called? lol
You guys never heard of an electric motor? I think they put them in saws and stuff.
Read it again, and you will see they are referring to performing a compression check on a motor.You guys never heard of an electric motor? I think they put them in saws and stuff.
1 - 20 of 24 Posts
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