Stroking the E30

[moatilliatta]

I have 275whp and I consider 25lbs weight penalty for a 6th gear and go 3.64..

But the 3.25 is the best compromise with cruising on the highway. Agreeing by one who also put the miles on them. I guess also I'm 1:1 filth..

Not much off the shelf 3.25 - 3.73, Minus Z3 diff 3.45, torsion or clutch pack$


I guess better than having it all together and wondering why it makes no tq with low compression... Glad to hear your machine shop caught that. AND! glad those CP pistons fit the slugs that were already punched!

[Digitalwave]

Why is that not enough power? Not enough power down low for the 3.25?

Just my opinion from a performance perspective. I guess if it's a car doing thousand mile road trips you'd want a really long gear like that.

[WAKman]

Pics on the cam mark didnt show..

Curious - would you deal with bimmerheads again?

Im debating on how to approach this.. my ol girl has 320,000 miles and I have a few blocks and a few heads..

I'm pretty happy with how this combo worked out. Bimmerheads was fine--they sent the wrong pistons the first time, but made up for it by sending the replacement CPs, which were more expensive, and picked up all shipping.

[WAKman]

IMO that isn't enough power to go with a 3.25 diff when paired with a G260 trans.

Power seems pretty good. Some of the pics are missing.

The car came with a 3.25, which the old tired engine had real problems satisfying, so I added the 4.10 LSD.

I take multi-thousand-mile road trips in my cars every year, and I'd put the 3.25 back in just for that. Last year I drove my 02 Boxster S 4,000 miles, down the coast from Seattle, across to Phoenix, and back up through Arizona, Utah, and Idaho. It was epic. Here we are on the rim of the Grand Canyon.



In a couple weeks I'll be team-driving from DC to Washington State, alas in a Jeep Wrangler and a Ford F150, helping family move. But the E30 will get the nod later in the summer if I can find the time. One of the big reasons I stuck with the M20 instead of a swap was my desire to retain the factory A/C and the factory look. Plus I love the M20.

[WAKman]

thinking about this:

https://metricmechanic.com/baby-six-m20-engines/

maybe just paying for the completed engine is the easiest... plus MO is driving distance for me.

That's about what I have in this engine. But . . . do you really want to miss out on the type of entertainment I had?

[WAKman]

Not sure why the photos didn't upload on my last post, but I think they've been added now.

[jbontke]

IMO that isn't enough power to go with a 3.25 diff when paired with a G260 trans.

Power seems pretty good. Some of the pics are missing.

Why is that not enough power? Not enough power down low for the 3.25?

[Digitalwave]

IMO that isn't enough power to go with a 3.25 diff when paired with a G260 trans.

Power seems pretty good. Some of the pics are missing.

[Panici]

I moved the cam forward one tooth, put everything together, and fired up the car. Guess what? It was a lot happier.

Lucky it wasn't further off, would have been a very expensive mistake!

(Also, your pictures aren't showing for some reason.)

[95BMWIC]

thinking about this:

https://metricmechanic.com/baby-six-m20-engines/

maybe just paying for the completed engine is the easiest... plus MO is driving distance for me.

[95BMWIC]

Pics on the cam mark didnt show..

Curious - would you deal with bimmerheads again?

Im debating on how to approach this.. my ol girl has 320,000 miles and I have a few blocks and a few heads..

[WAKman]

So . . .

I delivered the car to the dyno shop, and it ran a not-unhealthy 195 wheel hp and 200 torque, but something was clearly amiss. The power curves had ugly dips at 3500-4000, and the tuner suspected a mechanical problem, as did I. We scrubbed the mission, and I took the car home, planning, in order, to check the cam timing, compression, and leak down.

For some reason, BMW made it necessary to remove a bunch of stuff at the front of the engine to access the cam timing marks. To make sure I had everything just right, I pulled the radiator so I could see--plus, I had a new Mishimoto waiting to install. Finally got everything apart, turned the engine over to TDC, and discovered that when the crank marks looked like this:



The cam marks looked like this:



Uh oh!

After a zesty period of cursing and self-flagellation, I moved the cam forward one tooth, put everything together, and fired up the car. Guess what? It was a lot happier. It turns out that you need to get all the shiny spinny parts in the engine to do their stuff at exactly the right time. Who knew?

Back to the dyno we went, and, after a fair amount of tuning, here's what the engine produced:


Peak hp was 201 at the wheels, while torque was a stout 210 lb-ft. Applying a 15% drivetrain loss factor, that's 236 hp and 247 lb-ft at the crank, versus 168/163 from the factory. On the street, the car feels great--with the torque peak at 4300 rpm, combined with the 4.10 gears, it really pulls nicely in just about any gear. I had my doubts about the 4.10s, and for my planned long-distance drives, I'll probably install a 3.25, but the steep gears really make the car fun, though first goes by pretty quickly.

My next issue is a recurring hot-start issue, which reared its ugly head at the dyno. More on that next time.

[McGyver]

how do you write all that and then walk away for a couple of days?!?

[Digitalwave]

[Panici]

Talk about a cliffhanger!