Engine compression numbers!

[Mr Tank]

Hi

Decided to put some new plugs in my Taimar Turbo, and thought i would checked the compression figures. They range from 74 to 96 ! Anybody (Adrian) know what they should be on a Turbo!

She tided up nicely so I will take here to the three day Rushden Vintage Vehicle Show tomorrow!

Andy

[jellison]

sounds low. Not sure they should be much less than on a NA lump with say 160+

Not an expert though!

[B16 RFF]

Did you have the throttle wide open when you took the readings, and did the engine turn over at a brisk rate? It also helps to do it with all plugs removed.

Paul

[jellison]

You could call Adrian!

Or pop it on a set of rollers and see if making anything like what it should.

[Adrian@]

With 4 different compression ratios over the years..and assuming all the plugs out and full open throttle 145 would be nice.
Adrian@

[jellison]

Adrian@ said:

With 4 different compression ratios over the years..and assuming all the plugs out and full open throttle 145 would be nice.
Adrian@

aha - that is what I was thinking (so about the same as any engine really then).

Hmm seem very low then!! Eek.

[Adrian@]

The TVR Turbo has a piston mod to change compression, but the other versions (rooster booster/jan, etc) use low compression heads, which allowed trick pistons to be used and gain the strength in the crown surface,it having not had to be machined.
Adrian@

[Mr Tank]

Hi

Thank's for the comments etc!
Readings were done with all the plugs out and a cold engine, which had not been started for three months! Also this car sat for quite a few years with out being run, so I suspect stickie/stuck rings and other such nasties!

This just confirms that I need to do a rebuild at worst amongst other things!

Andy

[jellison]

Sounds like it. Once the pistons are wizzing round on the starter any standing about will not really count for much and what you see on the gauge is right.

Good luck.