i Valve Springs in my Eta head?

[325extatic]

Hi guys, just curious if I could put stock i motor double wound valve springs in my stock eta head? If so, is it worth it? I do have a chip, and my rev limit is much higher than stock... (5500rpm I believe).

It is just a curiousity. I don't dog my car out to hard too often, but if I can get a little bit more reliable fuel delivery/exhaust performance at the valves, I am not opposed!

Thanks!

Josh W.

[rs4pro3]

yes, no increase in performance just less risk of valve float.

[stylngle2003]

yes, no increase in performance just less risk of valve float.

which will save your motor in the long run

iirc, it requires machining of the head tho, so you might wanna research it a bit before you go all out

[Red325es]

anyone done this before?

[EtaSport]

I have.

It does not require machining of the head unless you put the i cam in as well. Which if you are pulling the head to do the springs, might as well swap out. I do recommend that you get the I spring seats. I modified the eta ones slightly to allow the inner spring to sit inside, but I would not do it again. The e retainers will work, they are a little smaller, but work fine.

I have no problem reving my 'eta' past 6000 rpms with the new springs.

[E30 Wagen]

I have.

It does not require machining of the head unless you put the i cam in as well. Which if you are pulling the head to do the springs, might as well swap out. I do recommend that you get the I spring seats. I modified the eta ones slightly to allow the inner spring to sit inside, but I would not do it again. The e retainers will work, they are a little smaller, but work fine.

I have no problem reving my 'eta' past 6000 rpms with the new springs.

So, if by machining the head you can swap in an i camshaft, is there a possibility to upgrade to a schrick camshaft or something as long as the eta is properly machined? Just hypothetically.

[EtaSport]

Yes you can run any cam you want as long as you drill the proper oil holes. The eta cam (4 bearing) has two oil pumps cut into the cam bearings to allow oil to run from the inlet (on the exhaust side) to the exhaust rocker shaft, then to the intake rocker shaft and finally to the oiler bar. The i cam (7 bearing) has only one cut in the middle bearing, and you must drill a hole in the head, as well as the two other bearings. confused yet? I have a picture if your curious.

I ran a 274 cam in my eta before going to the i cam. I like how it runs with the i cam much better.

[E30 Wagen]

confused yet? I have a picture if your curious.

I ran a 274 cam in my eta before going to the i cam. I like how it runs with the i cam much better.

yes, now i am even more curious.

What sort of cam will probably yield the most horsepower (if any)? Or, relating to an eta, will upgrading a cam mainly just make the engine run smoother/rev higher?

I want to take an engine rebuilding class so bad. I'll stop pestering with questions now.

[EtaSport]

well, im no expert by any means. learned everything by reading these forums so far. Unfortunately not too many people have done what I did, so I didnt have much to go by.



look at the holes in the head right by the holes for the head bolts. Those are what need to be drilled to allow oil to flow to the bearings and across the rocker shafts. They are set up at a certain angle, so unless you have a drill press, i recommend having a machine shop do it. Should cost too much, and they can do it while checking everything else and have it tanked.

Not sure which cam would work the best. Remember that the eta head has smaller valves and the ports will never flow as much as an i. I dont think I gained much by going with a higher duration cam, but didnt loose anything either. There is always a compromise.

[Jand3rson]

EtaSport, can you show me on that pic (by circling them or some other method) which are the holes already existing, and which are the holes you added? I'm doing this exact same thing to my new head (installing dual i valve springs and an i cam), so the more help you can give me, the better. Thanks!

[EtaSport]

okay, this sucks, but gets the job done. The circles are where you need to drill. All the others are already there.



the one in the middle on the exhaust side is where the oil comes into the head, and is also where the groove is cut on the cam. My grandfather (former machinest) did mine by hand using a protractor jig to set the angle.

[e30bimmerdude]

Ok, so in order for this to all work well, you would have to swap the ECU to make descent gains correct, i realize that you could do this without it but you wouldnt be able to REV to 6500...right? Also i dont know if you said this, but are the gains really noticable or just a slight increase? Thanks

[Jand3rson]

Ok, so in order for this to all work well, you would have to swap the ECU to make descent gains correct, i realize that you could do this without it but you wouldnt be able to REV to 6500...right? Also i dont know if you said this, but are the gains really noticable or just a slight increase? Thanks

No, you don't need to swap the ECU. While your car will still be limited to the stock eta redline, you can install a chip, which will raise the redline. I have a JimC chip in my car, which raises the redline to 5500.

EtaSport, thanks for the updated pic. So along with drilling the extra holes in the head, did you say that something needed to be done with the cam, also? I plan to use a stock 325i cam along with the i valve springs.

[e30bimmerdude]

Ok i understand this, cause i have the Jimc chip as well, so im already reving to 5500...But wouldnt you be able to rev to 6500 or 7000 if you were to swap the ECU? Also if you were to swap the ECU, atleast for me wouldnt it seem better to go ahead and swap the entire "I" motor....Ok for my other thought, does this swap yeild good gains, as in holy crap is this the same car type of gains or oh wow its a litle bit faster....mind you i already have the "I" intake mani, and T/B...which does help alot...so with that already being done i would imagine that this swap would yeild some pretty good gains correct, especially if you get the head ported/polish etc.... Thanks fellas, im looking to do the same... or simply swap the "I" motor, but the only thing holding me back is the ECU and wiring Harness.. i dont like wires..... Thanks again ~Troy

[Addissimo]

given the smaller valves on the eta head- I donno if you could really rev to 7000 rpm and get decent power at all.

Stick somewhere around 6k and your engine will be happy for a long while.

-Addis

edit:
wiring is really easy... just take your time.

You'd probably be better off sticking with the i motor, or at least the I head, and machining the pistons down (or whatever you have to do.) From there you could get a custom chip burned for your ecu, or do a piggy back, or megasquirt.

i think in the long run the hp/$ ratio will be in your favor.