zero compression on built motor.
#1
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zero compression on built motor.
OK so after a day and a half of assembling my car together, i try and fire it up and it wont. First thing I check is compression. Got 3 dead cylinders and one with 60 psi. So my guess is that the ls timing belt i forced on there threw the timing off just a hair (which it did) and that would be the most likely cause. It was pretty amazing to get an ls belt on a ls vtec with a gsr water pump. They say it cant be done and they are wrong and right. It can be done, but it cant be done properly. My other guess was that the people who build my motor didnt put piston rings in it (which i hope would be very unlikely. If this doesnt fix the problem I dunno what will. Throw out some ideas so I can get this thing running.
#2
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Re: zero compression on built motor. (turbo_b16_ex)
Did you do a valve adjustment?
Your timing being off a "hair" will not cause 0 compression. Check the valves.
Your timing being off a "hair" will not cause 0 compression. Check the valves.
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The head and valves have been rebuilt. New valve guides, 3 angle valve job. heads been resurfaced, block been decked. Everything has smooth matting surface
#4
Re: (turbo_b16_ex)
If you're not even sure the engine has rings in it, sounds like someone needs to figure out who's building the engine..
It's not like legos where you just put it together and it works.. there's ALOT to building an engine to get it to run right.. Alot of people just throw stuff together and hope it runs, and some luck out, others get it to run, but never right..
For instance,
What's your piston ring end gap?
What's your main and rod bearing clearance?
What's your crank endplay?
What's your piston depth in the bore?
What's your piston skirt to bore clearance?
There are ALOT of specs you have to check, ESPECIALLY when building a hybrid that wasn't meant to be built in the first place..
If you're not even sure the rings are in the engine, it might not be a bad idea to start from ground zero. Afterall, what's the worst that could happen? it wouldn't be built right and you end up smoking the whole engine and doing it all over again anyways, right?
It's not like legos where you just put it together and it works.. there's ALOT to building an engine to get it to run right.. Alot of people just throw stuff together and hope it runs, and some luck out, others get it to run, but never right..
For instance,
What's your piston ring end gap?
What's your main and rod bearing clearance?
What's your crank endplay?
What's your piston depth in the bore?
What's your piston skirt to bore clearance?
There are ALOT of specs you have to check, ESPECIALLY when building a hybrid that wasn't meant to be built in the first place..
If you're not even sure the rings are in the engine, it might not be a bad idea to start from ground zero. Afterall, what's the worst that could happen? it wouldn't be built right and you end up smoking the whole engine and doing it all over again anyways, right?
#5
Honda-Tech Member
Re: (Gadget)
If you didnt have rings when you were doing your compression test you would have heard the pistons bouncing.
First off if the motor has never been started before you need to turn it without injectors hooked and spark plugs in until you read oil pressure so the rings sit right.
Next since you have had head work done you need to do a valve adjustment. Depending on your cams do stock (.007in/.008ex).
Redo the timing and make sure your 100%. If your using a GSR pump use the GSR timing belt.
If you still dont have compression you need to take it to the shop and have them figure out whats going on.
First off if the motor has never been started before you need to turn it without injectors hooked and spark plugs in until you read oil pressure so the rings sit right.
Next since you have had head work done you need to do a valve adjustment. Depending on your cams do stock (.007in/.008ex).
Redo the timing and make sure your 100%. If your using a GSR pump use the GSR timing belt.
If you still dont have compression you need to take it to the shop and have them figure out whats going on.
#6
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I had the same problem with my motor when I dropped it in!
It ended up being that the machine shop tightened the valve lash screws all the way down so that when i dropped my cams in and did the timing I got impatient and tryied starting the car, I had no comprassion.
I say try doing the valve lash before ripping the motor apart.
It ended up being that the machine shop tightened the valve lash screws all the way down so that when i dropped my cams in and did the timing I got impatient and tryied starting the car, I had no comprassion.
I say try doing the valve lash before ripping the motor apart.
#7
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Re: (1crazysir)
<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by 1crazysir »</TD></TR><TR><TD CLASS="quote">I had the same problem with my motor when I dropped it in!
It ended up being that the machine shop tightened the valve lash screws all the way down so that when i dropped my cams in and did the timing I got impatient and tryied starting the car, I had no comprassion.
I say try doing the valve lash before ripping the motor apart. </TD></TR></TABLE>
yea that turned out to be it. No this block was built very professionally, all im saying was it crossed my mind that they might have forgot. It runs good. Got an oil leak i gotta trace and advance timing a little. Since my compression is dropped to 9:1, would that cause it to be a little rougher to start. It takes a few times in the morning.
It ended up being that the machine shop tightened the valve lash screws all the way down so that when i dropped my cams in and did the timing I got impatient and tryied starting the car, I had no comprassion.
I say try doing the valve lash before ripping the motor apart. </TD></TR></TABLE>
yea that turned out to be it. No this block was built very professionally, all im saying was it crossed my mind that they might have forgot. It runs good. Got an oil leak i gotta trace and advance timing a little. Since my compression is dropped to 9:1, would that cause it to be a little rougher to start. It takes a few times in the morning.
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#10
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Re: zero compression on built motor. (turbo_b16_ex)
Sounds like it is possibly timing involved, or the piston rings were not gapped correctly, or even the piston rings were not "staggered" like they should have.
#11
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no no, it runs great now. it was the valve adjustment. I was gonna wait till I had it running to do that but that was the cause of it as well as o reilly auto parts selling me the wrong timing belt.
#12
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yea uh no, it was their fault. I clearly stated that I needed a gsr timing belt, and what their computer pulled up was what they gave me, a LS timing belt. SO I returned it, went to autozone, and brought an ls belt to make sure it was larger, and they had the correct belt.
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