i just tested my na 86 rx7 without letting it warm up and it had 80 on all sides both rotors. Is this good compression? i imagine if i let it warm up id get a few lbs more.

 

Minimum factory spec is 85 psi with the engine warm, throttle open & cranking at 250 RPM. 90s to 100+ is much more favorable.

 

How do i crank at 250 rpm? and How do i do a compression test on a rotary. Maybe i did it wrong.

 

Well maybe it was a little higher after looking at my tester, but also take note that my battery was almost dead.

 

250 RPM is normal cranking speed with a charged battery. If you compression test with a near-dead battery, your numbers will suck.

 

I'd say they sucked then Ha. My dsm project haulted when i ended up with zeros on all cylinders. I pulled 2 engines and put one in all with trampoline poles and brute force all to have no damn compression. Well i decided to test the old seven and came up with this thread. Least she still runs.. Gotta love rotary!!

 

To test the compression first remove the lower air valve from the Tester the remove either the Top plus or the bottom plugs NOT BOTH. then have some one turn Engine over at full starter speed with a full battery while keeping the throttle open fully, either remove Fuel Inj fuse ,under hood or remove fuel pump fuse before you turn it over ,you will get a series of pulses which will show any low readings from the rotor you check, if one reading is high and 2 are low you have a worn,or broken apex seal if all are the same reading that is ok any low readings like 60lbs to 70lbs from the Engine makes it hard to start......

 

Yea i tryed with all plugs removed at first and just got air shots out. I didnt remove the thing and thats prob why it wasnt pulsing like i thought it should on a rotary. thanks

 

http://www.banzai-racing.com/compression_test.htm