186 compression psi??

[custommade]

Hi, Just got a SWB 2A with a 186 in it. It seems to have a lot of crank case pressure, oil out the dipstick, puffing out of the pcv hole if i pull the pcv hose out.
But.... It has about 140psi after a compression test and I thought that was ok but maybe not?

The PCV valve and hose are fine so I think it might be blowby.
And it does seem very low on power.

So do you think I'm up for a rebuild?
Anyone done one lately and know the cost of machining.
I would do the spanner work.

[bobslandies]

Hi,

Did you wash the PCV in petrol to clean it? It's a spring loaded valve so may be gummed up. Had to replace one once in a 186. Check the hose too for blockage.
Hope this is of some use.

Would think you would see 135-160psi at least compression in a 186 with only a variation of 5 or so psi.

Bob

[Bearman]

pretty sure (from memory) forgive me if I am wrong, the figure is 165psi with 10 percent variance between cylinders.

[custommade]

PCV seems fine, it rattles and he hose is clear.
Maybe it's just a shaged engine

[bobslandies]

pretty sure (from memory) forgive me if I am wrong, the figure is 165psi with 10 percent variance between cylinders.

Hi Brian,

My uncle used to marinise engines for GMH and rebuild Holden sixes and he tried to get a lesser variance between the cylinders so I remembered that. I rang him and he said that you are right - a 10% variation is ok. 165psi in a 9.2:1 186 would be a good engine, getting close to that on all cylinders would be ideal.

Bob