Square Four won't start
Posted: Thu Jul 09, 2020 7:40 pm
Hi all,
Hope you can help me. I just did a complete tear-down on my 1958 Ariel Square Four since it had not been running for a long time (save around my neighborhood after I bought it). Good thing I did dismantle it as I found a broken stud banging around in a push-rod tunnel and that the crankshaft oil ways were filled with concretions. Anyway, after the rebuild, I cannot get it to start. The cylinders were in spec, so I just honed them and installed new piston rings. but there was not even a splutter with each kick. I have a healthy spark (standard points and distributor) in all 4 plugs.
There is very poor compression - only about 50 psi - in each cylinder! I rechecked tappet clearance and all have appropriate gaps. I have not done a leak down test, yet, as I do not think it’ll answer the question at this point.
The first thing that comes to mind is that I have the valve timing all wrong. The odd thing is that the crankshaft pinion has three keyway slots at 120 degree intervals. The book says this is “in case alternative timing is required” Seems peculiar to me. Anyway, there are supposed to be two lines on the pinion that should point towards the camshaft when the appropriate slot is chosen. Mine only has a punch mark and I chose that to set the timing with. Is it likely that this is incorrect and that I should try timing with an alternative slot? If not, what other things should I try, short of removing the head, again?
I look forward to all responses and thank you in advance,
Paul.
Hope you can help me. I just did a complete tear-down on my 1958 Ariel Square Four since it had not been running for a long time (save around my neighborhood after I bought it). Good thing I did dismantle it as I found a broken stud banging around in a push-rod tunnel and that the crankshaft oil ways were filled with concretions. Anyway, after the rebuild, I cannot get it to start. The cylinders were in spec, so I just honed them and installed new piston rings. but there was not even a splutter with each kick. I have a healthy spark (standard points and distributor) in all 4 plugs.
There is very poor compression - only about 50 psi - in each cylinder! I rechecked tappet clearance and all have appropriate gaps. I have not done a leak down test, yet, as I do not think it’ll answer the question at this point.
The first thing that comes to mind is that I have the valve timing all wrong. The odd thing is that the crankshaft pinion has three keyway slots at 120 degree intervals. The book says this is “in case alternative timing is required” Seems peculiar to me. Anyway, there are supposed to be two lines on the pinion that should point towards the camshaft when the appropriate slot is chosen. Mine only has a punch mark and I chose that to set the timing with. Is it likely that this is incorrect and that I should try timing with an alternative slot? If not, what other things should I try, short of removing the head, again?
I look forward to all responses and thank you in advance,
Paul.