SidewaysFCvert

So I just bought a turbo 2 swAp and I would like to know what's the best way to check compression on it to know if it needs rebuilt or if it's good to go. Any help would be awesome thanks

jjcobm

iTrader: (18)

Attach the transmission and starter. Power the starter. Don't forget to hook up your compression tester and watch for 3 pulses. If using a standard compression tester, hold down the relief valve while cranking and read the 3 pulses. 80+ psi on all three faces is good compression.

SidewaysFCvert

That's what I did but powered it with jumper cables it read 35 on both rotors pulsing 3times each I was like **** but then I checked compression on my streetported n/a when it was cold and it read the same and when the n/a is warmed up it gets 109 on the rear and 112 on the front so should I be worried since they read the sAme cold?

RotaryRocket88

iTrader: (7)

You're doing something wrong if you're measuring 35 psi on either engine, regardless of temp. Prop open the throttle and put a very small amount of oil in through the exhaust ports of spark plug holes. The cold and warm measurements should be almost identical.

SidewaysFCvert

Man imma have to say ur wrong it does matter if it's cold or not I did the exact same thing u said same results both cars I let my street. Port warm up and it's back to better than new compression anyone else know what it should be around when it's cold

jjcobm

iTrader: (18)

Sounds like you have a bad compresssion tester or both of those engine are old. Like the man said, the numbers should read the same hot and cold. A good condition engine just doesn't have 30 psi of compression when cold and all of a sudden jump up to 100.

The spark plugs have no exhaust ports. Are you only removing the leading or trailing plug and NOT both when performing the test? Only thing I can think of is the engine isn't spinning fast enough when doing the test.

SidewaysFCvert

Well it might be the tester then and yes only removin one at a time so I'll follow up when I get a new tester I know the street port is in awesome condition cause it read that what it ran the day I got it home exact same numbers And there are like 30k and that was with a different tester so the one I have now might be faulty

RotaryRocket88

iTrader: (7)

That's nice, but you're wrong. All the engines I've compression tested say otherwise. The turbo engine in my car tested at 110-120 psi on all faces sitting on a pallet.

It doesn't even make sense for an engine to have almost no compression cold. If it did, you would never get it to start up. An engine with low compression on two of six rotor faces is very hard to start. What you're proposing is that every rotary engine acts like a completely blown engine on start up. That's just not the case.

GST7

iTrader: (2)

So wut would be good compression for a turbo motor?

RotaryRocket88

iTrader: (7)

Minimum spec in the FSM is 85 psi, but 100+ psi is ideal.