piston-return-spring
New Member
100 psi seems very low...
Mine showed around 158 psi on all 4.... (has only done 25000 km)
New is 160 psi i think.
Mine showed around 158 psi on all 4.... (has only done 25000 km)
New is 160 psi i think.
mingdiesel
Member
Hi
I tested compression on my Series III 8:1 CR 2.25 Petrol before I removed it for overhaul and compression test was approx 145 psi evenly across all 4 bores when warmed up (smoking on cold start was an embarrassment at public gatherings & decontaminated the garage too) 7:1 would of course be less. Some of the smoking was probably due to worn valve guides & stem seals so head has been reconned now too, 9:1 Gasflowed ACR Stage 1 head.
After dismantling engine, upon inspection a lot of irregular wear was present at top of bores, leaving quite a wear ridge near top of bores hence reason for re bore.
Talking to some experts this uneven top end wear appears relatively common on 4 cyl 2286cc Petrol Engine & some more experienced guys would probably have left it alone).
Mine has now been re-bored +0.020 oversize with new pistons, rings, shells, crank, clutch, carb overhaul, and timing etc I'm hoping with good quality lubrication, modern lubricity additives & regular maintenance I won't have to re-build this engine again for a very long time.
I think some of this wear is probably down to poor lubrication, over rich mixture from worn out carb (Zenith 36IV requiring overhaul) & infrequent use & consequently maintenance where oil has completely drained back down resulting in dry start ups.
Now looking at priming oil lubrication system manually when engine hasn't been run for a few weeks (ie over winter) so oil pressure & lubrication are present at start up (cheaper than a rebuild!), any ideas if/how this has already been done please let me know (foot operation seems good simple way & theraputic too).
Mingdiesel
I tested compression on my Series III 8:1 CR 2.25 Petrol before I removed it for overhaul and compression test was approx 145 psi evenly across all 4 bores when warmed up (smoking on cold start was an embarrassment at public gatherings & decontaminated the garage too) 7:1 would of course be less. Some of the smoking was probably due to worn valve guides & stem seals so head has been reconned now too, 9:1 Gasflowed ACR Stage 1 head.
After dismantling engine, upon inspection a lot of irregular wear was present at top of bores, leaving quite a wear ridge near top of bores hence reason for re bore.
Talking to some experts this uneven top end wear appears relatively common on 4 cyl 2286cc Petrol Engine & some more experienced guys would probably have left it alone).
Mine has now been re-bored +0.020 oversize with new pistons, rings, shells, crank, clutch, carb overhaul, and timing etc I'm hoping with good quality lubrication, modern lubricity additives & regular maintenance I won't have to re-build this engine again for a very long time.
I think some of this wear is probably down to poor lubrication, over rich mixture from worn out carb (Zenith 36IV requiring overhaul) & infrequent use & consequently maintenance where oil has completely drained back down resulting in dry start ups.
Now looking at priming oil lubrication system manually when engine hasn't been run for a few weeks (ie over winter) so oil pressure & lubrication are present at start up (cheaper than a rebuild!), any ideas if/how this has already been done please let me know (foot operation seems good simple way & theraputic too).
Mingdiesel
