4bd1 cylinder compression

[fid-def]

An anyone tell me the cylinder pressure of a 4 bd1 with engine running I've just checked mine at the heater plugs and am getting 615 psi - haven't checked by manual hand turning. I can't find details in forum search.

[Blknight.aus]

dunno, never tried it with the engine running...

270ish PSI from memory on the starter with all the glow plugs pulled and the IP held in the stop position.

(compression ratio*15)

[Dougal]

(compression ratio*15)

Plus heat from compression. Compress it slowly without leakage and you'll get compression ratio x 15.

[Blknight.aus]

correct and theres a rule for working that out too.....

(buggered if I can remember it tho) I use compression*15 as a ball park for minimum pressure for a cold dry compression test, less is bad and the variation should be less than 10% from highest to lowest.

same principle applies to combustion pressures when you're using that for fault finding its not so much the overall number (unless its stupidly off base) but the variation between that is most important.

huuummnnn, aaaaahhnd as it is written in the good book chapter 103 verse 31, 313-441PSi with 71psi max variation, so shall it be...... ommnnnnnnnn