Thread: Holden 161

The "good book" in my 'library' lists the compression (hot) as 130-170psi so the numbers you have are OK. I'd suggest you put a squirt of oil into each cylinder and repeat the exercise, noting how the compression gauge registers. If the pressure builds very quickly then plateaus, it indicates excellent sealing from both piston rings and valves. If it takes a while to reach max then there's a bit of a leak somewhere. If having squirted the oil in you get a higher reading, then it indicates rings.

Depending on how far you want to take it, it's not a big job to remove the head. You could probably get away with a DIY valve grind and add new stem seals, carby overhaul kit, new points/plugs/HT leads and you're good to go!

good luck!

Originally Posted by gunguy

Thats probably the way i'll go if the 161 proves to be a rebuild

ihave a 161 in workshop 5.000 miles only spare to requirements pm if interested

My workshop manual gives a 161 as producing 114hp @ 4600 rpm and 157 lb.ft @ 2000 rpm. Compression pressure (hot) 130 -170 psi. So on the face of it, with only one cylinder within specification, your engine appears well worn.

The Holden Red 161 ci or 2600 cc are a good donk.
Reasonable power and good economy so enjoy it!
Cheap enough if you have to reco it too!


Cheers, Mick.

Try this to help free up gummed rings, squirt a small amount of transmission fluid in each cylinder, leave to soak into and around rings for a day or so, then start up motor it will blow a little bit of white smoke until the transmission fluid burn off, warm up engine and repeat the compression test on a hot motor. If you don't want to use trans fluid you can buy a product that does the same thing.

Cheers Chris

Originally Posted by gunguy

Just did the compression test, what insightful reverlations do these numbers give the learned forum members
Cylinder 1: 127 2: 127 3: 125 4: 110 5: 127 6: 140.
Cylinder 4 and 6 were tested twice.

any thoughts

Just occured to me: Were these numbers obtained from a cold engine or was it at operating temp. If they were done "cold" then you ought probably fire it up and run for a while to get it hot, then do the readings again and use those results. Don't forget to remove all the plugs first and get someone to turn the engine over using a wideopen throttle while you manage the compression gauge. As mentioned previously, the behaviour of the gauge needle can provide a good indication of condition of rings/valves...

OK. Some new numbers from a warm engine,
1: = 135
2: = 139
3: = 141
4: = 120
5: = 135
6: = 148
I will be getting new valve seats etc so the motor will run unleaded, so i should probably get the block honed and new rings, bearings and seals while I'm at it. This is going to be the daily drive. any thoughts on these new numbers though.
cheers
George

I Would definitely rebuild the bottom end if your going to do the head, with those's numbers and a reco head the rings would have much life left in them, you won't really know what needs to be done until you get it all pulled down, eg bearing, rings, de-ridge the bores and hone, also cam and cam bearings, at a guess for a complete rebuild will cost about a $1000 if you do most of the work yourself. I may be cheaper to find another motor thats a known good runner.

Cheers Chris