hey

over the last couple of days i have come across an onld 1100s 1275 engine which only cost me $50.. still there complete but it has been siting on a farm for god knows how meny years... she all looks to be ok.. 40tho over size but thats about all i know. seems to turn over just fine and has enough oil pressure to turn the oil pressure swich off with the starter motor.

ive gone through and checked the compression of each cylinder and there all between 70 and 80 on the gauge which is in the red.. now ive got a few questions

1. is it possilbe to tell wether the engine will start with compression as low as it is? or is it just low because its cold and hasnt runnn in quite a few years? just want to get all ur opinions before i bother even tryn to start it.

2. and what capicity is a 1275 bored out by 40tho?


cheerz matt.

Did you have WOT when testing? If not then compression could be fine. As long are all reading were pretty close.

umm i didnt even have a manifold on there so yes i supose the throttle was wide open.

Pressure is low but at least they are pretty equal which is a good sign.
Will come up once run.
+.040" is 1310cc.

ps. squirt a teaspoon of oil into each cylinder before starting it.

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DrMini- 1970 wasaMatic 1360, Mk1S crank, 86.6HP (ATW) =~125 @ crank, 45 Dellorto (38 chokes), RE282 sprint cam, 1.5 rockers, 11.0:1 C/R.

cheerz im liking whats goin on. $50 sitting on a farm for god knows how meny years. was expecting worse....

$50 is great... but don't expect it to last long if you stick it in a mini and start thrashing it... been there, done that

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did I tell you that I won a trophy?

I've had plenty of engines with less than 80 psi and they all ran. The compression will probably come up once the oil gets flowing. If it's a fairly even compression across the board then that's a good sign, and it will put less pressure on your starter motor being so low.

Also bear in mind it may have low compression pistons, which only blow around 120psi when everything is new anyway.

If it were me, I'd put a little bit of oil down the bores and connect up some ancillaries and fire it up, if you're otherwise going to rebuild it you may as well try.