Deep pocket pistons in a stock M20 build

[jgilber0]

After changing my timing belt, I started thinking it would be nice to make my M20 into a non-interference engine. I just use my E30 around town, it’s a cabrio, so no racing and I’m not even allowed to autocross it without adding a rollbar. While I love the MM (Metric Mechanic) 2900, I have a small budget.

Is it possible to use MM deep pocket pistons in an otherwise stock M20 build?

What issues might arise from the reduced compression?

Would driveability suffer?

[E30-325iS]

There's no point, just keep your maintenance up and you won't have a problem.

[digger]

the pockets would get too close to the ring groove and may even not be enough crown thickness. MM use a bigger diameter piston and lower the top ring

[jgilber0]

Thanks!

So much for that idea...

Annoying amount of work to change that belt. I suppose I’ll get it done faster when I have to do it again in four years.

[e30davie]

My timing belt snapped in my car the day after I bought It. Based on the condition of the belt I reckon it had never been changed. It was seriously deteriorated. You rubbed the belt with your fingers and bits of rubber would rub off. What I'm getting at is the belt has to be sooooo neglected to fail. If you change it when you are supposed to you have nothing to worry about.

[digger]

its like 4 hours to do a TB in a home garage. it will take you more than 4hrs to pull the head and cut those pockets, clean it out and put it back together.

you would lose about 7cc and almost a full point of CR