Engine rebuild. Possible to test compression and oil pressure before reinstall?
#1
Senior Member
Thread Starter
Engine rebuild. Possible to test compression and oil pressure before reinstall?
Hey there. Executive summary: Is it possible to check an engine rebuild before wrestling it back in to the car?
Have the engine out of my son's 1981 RX7 FB. Took it apart, and rebuilt using an Atkins Rotary rebuild kit kit. At the point where the engine is now stacked back together and the through-bolts in and torqued. Starting in on front cover, oil pump etc and wondering if there is a way to test oil pressure and engine compression at this point to check our work. I have the Atkins Rotary rebuild download and they do show oil pressure testing with a dial gauge, but my uneducated guess is such equipment is inaccessible to us mere mortals? Screenshot is of the Atkins video, our engine aint that pretty!
Atkins Rotary video screenshot of oil pressure test.
Details details... FB with oil cooler under radiator (not beehive). Rebuilding with new seals and springs. Engine interior was in remarkably good condition. Rebuild triggered by multiple oil leaks, but compression and hot start really good prior to rebuild. Working in the driveway and a shed, good with tools and an accomplished MacGyver, but by no means an auto mechanic.
Have the engine out of my son's 1981 RX7 FB. Took it apart, and rebuilt using an Atkins Rotary rebuild kit kit. At the point where the engine is now stacked back together and the through-bolts in and torqued. Starting in on front cover, oil pump etc and wondering if there is a way to test oil pressure and engine compression at this point to check our work. I have the Atkins Rotary rebuild download and they do show oil pressure testing with a dial gauge, but my uneducated guess is such equipment is inaccessible to us mere mortals? Screenshot is of the Atkins video, our engine aint that pretty!
Atkins Rotary video screenshot of oil pressure test.
Details details... FB with oil cooler under radiator (not beehive). Rebuilding with new seals and springs. Engine interior was in remarkably good condition. Rebuild triggered by multiple oil leaks, but compression and hot start really good prior to rebuild. Working in the driveway and a shed, good with tools and an accomplished MacGyver, but by no means an auto mechanic.
#2
GSSL-SE
iTrader: (1)
The test in that picture is a coolant pressure / leakdown test. It just makes sure your water seals were installed properly.
https://www.pineappleracing.com/cool...estercspt.aspx
Unfortunately, it is not possible to properly test oil pressure or compression on a fresh rebuild outside the car. Oil pressure needs to be measured with engine running. While you could do a compression test as it sits, it wont read correctly until all the assembly lube has been burnt off and should be tested with the engine warm.
Cheers and best of luck with your fresh engine!
https://www.pineappleracing.com/cool...estercspt.aspx
Unfortunately, it is not possible to properly test oil pressure or compression on a fresh rebuild outside the car. Oil pressure needs to be measured with engine running. While you could do a compression test as it sits, it wont read correctly until all the assembly lube has been burnt off and should be tested with the engine warm.
Cheers and best of luck with your fresh engine!
#3
Moderator
iTrader: (3)
i know of devices to help you build oil pressure and check for leaks with the engine out, but to actually check oil pressure in any meaningful way, i would tend to think you need the engine actually running.
you can check the compression with the engine out, but keep in mind that the numbers change when the engine is hot. also, as 1badFB stated, you have to factor in all the goop that's in the chambers right now.
you can check the compression with the engine out, but keep in mind that the numbers change when the engine is hot. also, as 1badFB stated, you have to factor in all the goop that's in the chambers right now.
#4
Senior Member
Thread Starter
Aha... correct, coolant not oil. Just ordered the tool from Pineapple. Will add it to my box of 'used it once' tools when done. Maybe there should be a tool trade / loan page on RX7Club? Then again, tool loaning always leads to trouble.
Makes total sense on compression and oil pressure only being possible when engine is running, just had some wishful thinking that maybe there was a way around putting the engine back in and seeing what happens. Really concerned about that first turn of the key, particularly as the car is out in the street and the neighbors will all be watching!
Makes total sense on compression and oil pressure only being possible when engine is running, just had some wishful thinking that maybe there was a way around putting the engine back in and seeing what happens. Really concerned about that first turn of the key, particularly as the car is out in the street and the neighbors will all be watching!
#5
Senior Member
iTrader: (4)
I would prime the oil system before you first try to start it. Might not make a huge difference but who knows.
What I did with my rebuilt 12A:
-Make sure oil cooler is full. Not sure if you would have drained this or not. Can keep putting oil down the oil filter 'feed' side to do this.
-Pour some into the center of the oil filter housing. Install filter
-Remove spark plugs, crank car in short intervals. Check oil level in between. Stop when you see a bit of pressure build.
-Install plugs
-Start it and keep it running!
What I did with my rebuilt 12A:
-Make sure oil cooler is full. Not sure if you would have drained this or not. Can keep putting oil down the oil filter 'feed' side to do this.
-Pour some into the center of the oil filter housing. Install filter
-Remove spark plugs, crank car in short intervals. Check oil level in between. Stop when you see a bit of pressure build.
-Install plugs
-Start it and keep it running!
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