06-02-2022, 11:18 PM
Hi,
The engine is very tuned with a newman race cam, largest possible inlet valves, reshaped followers, ported and gas flowed block and reprofiled head to allow the high lift cam without valves hitting the head. It has an HS2 carb with blue spring and #5 needle (I used a #6 last year until mid season but had huge issues with fouling plugs and misfiring though I did win both VSCC autosolos and the car will do > 65mph on the road). It is running an original Bosch 009 distributor (with the limit on centrifugal advance setup) and NGK plugs. Timing wise the its currently statically set at 7degrees before TDC but then adjusted slightly when running to find fastest idle and then retarded some.
The reason for my original question was that I put the engine together originally and following discussions about putting together another engine for my trials car (the piston rings for which have clearly marked top and the order in which they should be installed) I realised that I didn't realise that piston rings had a top/bottom so thought this could be the reason behind my low compression. Since I have also had issues with oil in the bores. As the flywheel has made a habit of coming loose and now running with too much run out then it appeared to be a good shout to take a look to confirm one way or the other at this point.
Since my A7 is the only car I have ever hand cranked then I don't really have anything to compare to when thinking about whether it has a good bounce. The only thing that I have thought about is that because I have an SU carb when I spin the engine over (all plugs removed) with the compression tester the dashpot is of course still very much down so should try with it removed.
Cheers
David
The engine is very tuned with a newman race cam, largest possible inlet valves, reshaped followers, ported and gas flowed block and reprofiled head to allow the high lift cam without valves hitting the head. It has an HS2 carb with blue spring and #5 needle (I used a #6 last year until mid season but had huge issues with fouling plugs and misfiring though I did win both VSCC autosolos and the car will do > 65mph on the road). It is running an original Bosch 009 distributor (with the limit on centrifugal advance setup) and NGK plugs. Timing wise the its currently statically set at 7degrees before TDC but then adjusted slightly when running to find fastest idle and then retarded some.
The reason for my original question was that I put the engine together originally and following discussions about putting together another engine for my trials car (the piston rings for which have clearly marked top and the order in which they should be installed) I realised that I didn't realise that piston rings had a top/bottom so thought this could be the reason behind my low compression. Since I have also had issues with oil in the bores. As the flywheel has made a habit of coming loose and now running with too much run out then it appeared to be a good shout to take a look to confirm one way or the other at this point.
Since my A7 is the only car I have ever hand cranked then I don't really have anything to compare to when thinking about whether it has a good bounce. The only thing that I have thought about is that because I have an SU carb when I spin the engine over (all plugs removed) with the compression tester the dashpot is of course still very much down so should try with it removed.
Cheers
David