2.7i Pros and Cons

[jeffnhiscars]

I'm going to throw another curve at this never ending discussion. I'm about to put a 731 head off of a b23 on to my chipped but otherwise bone stock ETA. The head will have new +2 valves, new intake guides, a mild port, 323 intake & cam & b25 TB.

All the externals will be stock ETA and I'm hoping to dyno it as is and then after the head is on. This will be with all ETA externals other than the TB.

Anyone think I'll get b25 hp ?

[Red_liner740]

If youte gonna go through the trouble of pulling the engine, might as well go 24v. They are dirt cheap now.

[jeffnhiscars]

If youte gonna go through the trouble of pulling the engine, might as well go 24v. They are dirt cheap now.

Who said I was pulling the engine ?

[digger]

i would find a good used engine and swap it, screw building a stock b25 when the cost to do a 2.8L is a relatively small difference

[digger]

I'm going to throw another curve at this never ending discussion. I'm about to put a 731 head off of a b23 on to my chipped but otherwise bone stock ETA. The head will have new +2 valves, new intake guides, a mild port, 323 intake & cam & b25 TB.

All the externals will be stock ETA and I'm hoping to dyno it as is and then after the head is on. This will be with all ETA externals other than the TB.

Anyone think I'll get b25 hp ?

you should get there with a proper tune

[jeffnhiscars]

you should get there with a proper tune

I do hope you are right :)

[Red_liner740]

Who said I was pulling the engine ?

You said the rod bearings are shot. How else will you rebuild it?

[digger]

different person with shot bearings

[jeffnhiscars]

I've put a lot of effort I. To deciding on intake and head layouts, but now that my 731 is in the shop it's time to discuss exhaust. I fully intend to go dual when the parts appear but I'm more interest in the exhaust manifold and down pipes.

Does anyone have side by sides with b27 and b25 exhaust manifolds ?

Given that I have a 731 what reasonably priced header options do I have ?

Should I just mate a stock b25 to the ETA manifolds ?

Etc etc

[SkiFree]

If youte gonna go through the trouble of pulling the engine, might as well go 24v. They are dirt cheap now.

howabout no. I always get a good chuckle at M52 kids (exception being Simon).

[agent]

I always get a good chuckle at M52 kids (exception being Simon).

Why?

[SkiFree]

Because typically it's doofuses who don't have money for anything better (swap wise) and haven't driven a decently built M20.

Perhaps someone should start another "which swap" thread for us to all have a jolly time in and let this one remain being about rebuilding Jeff's M20?

[jeffnhiscars]

Speaking of which :)

Is an IX harness suitable or will it turn the ETA into a 4wd ?

[modernist]

Is an IX harness suitable or will it turn the ETA into a 4wd ?

HAHAHAHAHAHA

Does anyone have side by sides with b27 and b25 exhaust manifolds ?

No, but the exhaust ports on all M20 heads are the same. b25 has larger downpipes. b27 b20 and b23 have identical exhaust manifolds (same part numbers), b25 is the only M20 with a different part number.

Should I just mate a stock b25 to the ETA manifolds ?

My 2.7i runs very strong with the stock eta exhaust. I had the pinched section under the rear subframe replaced with a round section of pipe, otherwise it's stock. Silent at idle, quiet under 3k, muted but delicious BMW wail above that.

[jeffnhiscars]

HAHAHAHAHAHA

No, but the exhaust ports on all M20 heads are the same. b25 has larger downpipes. b27 b20 and b23 have identical exhaust manifolds (same part numbers), b25 is the only M20 with a different part number.

My 2.7i runs very strong with the stock eta exhaust. I had the pinched section under the rear subframe replaced with a round section of pipe, otherwise it's stock. Silent at idle, quiet under 3k, muted but delicious BMW wail above that.

I half expected someone to take my 4wd comment seriously so thanks for that.

As long as all the ports, manifolds and pipes play well together I'll stick with stock for now and see how that goes since again, the goal is to do this incrementally so the results of each step are not disguised.

At some point ill be tempted to try a b25 dual pipe and will report back on any before and after differences.

Thanks for the input.