IM 240 test

[sjelby]

Yep. Gas is very hard on a new engine. But an engine with a few k's on it has been hardened up . Particular the valve seats,
When reco'ing a head for gas , hardened seats need to be put in .
Saying that though
If you build a cobra " designated gas" would you need to go through the emissions test?

[400TT]

Originally Posted by sjelby

If you build a cobra " designated gas" would you need to go through the emissions test?

If you need to comply with ADR 37/01 emissions, then no emissions test required if you are running gas.

[Outwest34au]

Originally Posted by sjelby

Yep. Gas is very hard on a new engine. But an engine with a few k's on it has been hardened up .

I believe the main issue here is that a new gas (LPG) engine will not bed the rings in correctly as gas is a dry fuel compared to petrol.
When I did my LPG course we had a recipe with good old Bon Ami powder mixed with engine oil, it was distributed evenly between the pots and the engine wound over exactly 50 times by hand with no heads on the motor, after 50 turns the heads got fitted up and the engine started alledgedly blowing the dry powder out the exhaust, The teacher at the time said 150 turns would wear the rings past the useable limit.

Thhats what she said anyways.

[Rob. Smith]

Originally Posted by Outwest34au

I believe the main issue here is that a new gas (LPG) engine will not bed the rings in correctly as gas is a dry fuel compared to petrol.
When I did my LPG course we had a recipe with good old Bon Ami powder mixed with engine oil, it was distributed evenly between the pots and the engine wound over exactly 50 times by hand with no heads on the motor, after 50 turns the heads got fitted up and the engine started alledgedly blowing the dry powder out the exhaust, The teacher at the time said 150 turns would wear the rings past the useable limit.

That's what she said anyways.

My new engine was run in on petrol...95 octane...it runs on lpg now. Why would you run an abrasive through a new engine...some of the 'grinding paste' would find it's way to the bearings and other bits. When running in an engine there's oil in the engine and it's being applied to the bores as it's supposed to be... fuel (petrol) would wash the bores any way (above the rings ) I reckon a proper hone during the build would create the required bore 'condition' and a wet run in would do the job. "Flex-Hones" would do the job of 'Bon-Ami' but you still have to wash the block out before the bearings and bits are fitted. That's my thoughts. I'm not criticising...just talking.