Going turbo eta. Should I head swap or cam/valve swap?

[88driftIS]

Well I am building the my 86 eta for drifting and the stock 2.7 isn't going to work. I need the revs. I am not looking to get huge power. Just around 300. The question is would it be worth it to swap the hole head for the is, or just swap out the cams and valves for is ones? The head is going to be coming off to be rebuilt anyway, and if I get an is one it will get rebuilt as well. So internal swap or whole head swap?

I am leaning towards just swapping the internals. Maybe even going with a custom reground cam that would still work with stock is springs. All I really want are the revs. What are you guys with the budget stroker revving your motor to? Thanks ahead of time for any help.

[88driftIS]

No input....:(

[Farbin Kaiber]

Wow. That's gonna be costly. Check out the turbo forums on that other e30 forum, as they have more FI stuff going on over there. There are some guys here that might be able to point you in the right direction.

Also, try the FI subforum here, as they will have more info than the reqular m20 subforum.

[yberther]

the springs on the e head are what make it weak. Just swap the whole head.

specs on turbo set up?

[88driftIS]

I am going to be using a t70 turbo on a reworked ebay turbo manifold, custom IC piping, 3 in exhaust with a dump for when I am on the track, fmu/chip, tial wg, hks ss bov, and not sure on the intercooler yet. I am only looking to run 10-15 psi. Just enough to be able to get the wheels to spin easier. Then when this motor pops, time for an m50 non-vanos.

[kronus]

Swapping the valves will not change anything at all, and just sticking in an I cam is more work than it's worth (you will need to drill the head for 2 more oil journals, and the ports on e heads are tiiiiiny). You will want to stick on an i head (i head on e pistons makes for low compression, which is arguably good for turbo) and custom management.

[VacMan]

As a bonus, swapping an I head onto a stock ETA bottom end will net you right around 8.0 compression which will be much nicer to boost. Check this thread for more information.

[88driftIS]

When I said valves I meant the springs... I don't know why I kept saying valves...

[88driftIS]

So if I am only looking to rev higher and not worried about the extra hp from the i cam and bigger ports. Could I safely rev higher, lets say 6.5k or 7k rpms, with just the springs? I am trying to figure out my options. Being a broke ass student ftl...

[kronus]

BMW designed the eta cam with a very specific RPM range and power range in mind. IMO those extra 2K RPM would be pretty useless on stock eta internals.

[88driftIS]

guess I need to find and is head...

[yberther]

yea. basically that will allow you to get those higher rev's... also why not MegaSquirt?

and n/v m50 is such a cheaper project than a t70. You'll also need new injectors, and depending on that possibly a pump (I'm not totally sure on the pump, its not usually talked about).

[StereoInstaller1]

The single valve springs are part of a system: soft springs, low revs, needs only half as many cam bearings, higher compression...all designed for EFFICIENCY!

Instead of thinking like "stick an i head on an ETA block" think the other way around...stick an ETA block under the i motor.

You really would be better off doing megasquirt and an i/eta motor than any other combo.

But seriously, quit thinking 300HP right now. You are gonna break shit in a hurry, and "broke ass college student" and "300 HP" sounds like a recipe for disaster.

[Nicademus]

The single valve springs are part of a system: soft springs, low revs, needs only half as many cam bearings, higher compression...all designed for EFFICIENCY!

Instead of thinking like "stick an i head on an ETA block" think the other way around...stick an ETA block under the i motor.

You really would be better off doing megasquirt and an i/eta motor than any other combo.

But seriously, quit thinking 300HP right now. You are gonna break shit in a hurry, and "broke ass college student" and "300 HP" sounds like a recipe for disaster.

I agree with StereoInstaller, broke and turbo don't mix.

I'd just sell the eta and get an "i" with LSD. Thats all you need to get started and have fun.

[88driftIS]

I have two cars, so if it blows it's not a big deal. I rather not get rid of the car because the body is really straight. I already have the t70, traded some honda crap for it. As for the pump, probably end up with a walboro 255. I know all about turbo and costs, I have turbo'd a couple of cars myself. My question was, in order to get a little more rev would it be cheaper/easier to swap the entire head, or springs and cam.

This will be an all winter long project. So yeah I may not have a lot of money that can go into to this, but it will be done little by little. I am not in a rush. I don't have to have this car running by a certain date. Have either of you ran a turbo set up with an fmu. It's not as bad as people put it out to be. If you do it right they will last just as long if not longer the a piggy back or full out stand alone. You may not get as much power, but it is a lot easier and a lot less stressful.

plan:
-suspension
-wheels
-find is head
-get mls head gasket and good head studs
-replace bearings and piston rings in eta bottom end
-replace oil pump(water pump and timing belt are new)
-have block and head decked
-reassemble motor
-break in motor
-find a 3.x lsd
-find a decent set of high output injectors
-find some sort of tunning set up, probably will end up with m/s when i do want more power
-then turbo it