Dual valve springs into an eta head? Cam options?

[Jand3rson]

I was curious if this could be done or not. I know you can't just slap a 325i head onto an eta block, but I've always been curious if swapping dual valve springs in was possible,
and if it would net any real gains.

Also, can a 325i cam go into an eta head? If not, what performace cam options are there for an eta head?

[kco325]

As far as I know, dual valve springs are a swap with no mods necessary, and seeing as how I can hear the valves float in my eta at redline (5500) I can see how it would let you rev higher, but since your crappy cast crank might disintegrate, that might not be a great thing to do.
I think the cam can be swapped but you need to drill oil journals in the 'e' head... dont quote me on that though.
I know that you can put an I ecu in an E, but it would be for minor gains and the risk of overrevving.
I also know that you can bolt an I flywheel and clutch assembly onto an e, for very noticeable gains (I think it's about 10lbs, from dual mass - probably - to single). I'm doing that when I change my clutch, since I plan to swap engines anyway sometime this year.

[Jand3rson]

I already plan to keep the flywheel from this 325i I'm parting out and have it lightened, then put into an eta.

Yes, I'm planning to buy an eta. Save the flaming for another thread.

[modifiede30]

I've heard several mechanics indicate that the cast crank breaks less frequently than the forged. Maybe this is due to the fact that most people turbo charge the car with the forged. However, in a naturally aspirated e30 engine, you should be safe to 6000 rpm's with the cast crank if its not going to be driven at this level consistently.

As for dual valve springs, its not going to do much unless you change the cam as well, and if you're going to do this, change the intake or the cam will be a pointless effort.

[Jand3rson]

I'm going to have a eta head and block with a 325i intake manifold and throttle body, and I plan to have the head port matched to the larger inlets of the i manifold. I did this same thing on my old eta (minus the head work and port-match) and it provided pretty noticeable gains. I also plan to chip the motor, and will be running a full 325i exhaust, all the way up to the exhaust manifolds, with no cat. Since I know I can change the valve springs now, I will be uprgrading the cam as well. It's going to be one seriously quick eta.

Just to squash any stupid flaming, I'm doing this to an eta for several reasons. My old eta was plenty fast for me when I had it. I'm not trying to build a racecar, and I'm not trying to beat anyone in street races. I want to have the higher torque and better gas mileage of an eta (though I know I will lose a little of both with all these mods, but not very much), but I also want it to have good punch. And if I ever do decide that I want more power, I'l already have the necessary bottom end to build a stroker in the car.

[rs4pro3]

That sounds like a good plan, when I drove my friends eta I loved the low down torque unlike what the I has. Of course though there is just something about peggion the limiter at 6500 that is fun :P

[reelizmpro]

Sure you can. In fact all you need is the inner spring but it's best to get them as a complete set anyway. A 325e with dual springs and i cam puts out around 158HP or so @ flywheel according to Dinan's literature on E to i conversion kits.

[Jand3rson]

Sure you can. In fact all you need is the inner spring but it's best to get them as a complete set anyway. A 325e with dual springs and i cam puts out around 158HP or so @ flywheel according to Dinan's literature on E to i conversion kits.

WOW! I plan to just buy a Schrick cam, what's a good profile? I was thinking 284/272.

Got a link to that info at all?

[reelizmpro]

Sure you can. In fact all you need is the inner spring but it's best to get them as a complete set anyway. A 325e with dual springs and i cam puts out around 158HP or so @ flywheel according to Dinan's literature on E to i conversion kits.

WOW! I plan to just buy a Schrick cam, what's a good profile? I was thinking 284/272.

Got a link to that info at all?

No links that I know of has that info. E to i kits aren't as popular as they once were back in the late 80's/early 90's. The kit included a cam/valve springs/tach/differential ring gear and custom chip.

[Jand3rson]

Cool. Anyone have a good idea for a cam profile?

[modifiede30]

274 is a good compromise for a street car. I've heard that once beyond this, idle goes to hell.

[Jay Stock E30]

I've heard several mechanics indicate that the cast crank breaks less frequently than the forged. Maybe this is due to the fact that most people turbo charge the car with the forged. However, in a naturally aspirated e30 engine, you should be safe to 6000 rpm's with the cast crank if its not going to be driven at this level consistent

I was talking with a mecanic and he said he saw almost no differnece in the reilibility of the forged vs. cast cranks

I personally ran 15psi of boost on an eta crank all the way to the 7k redline for about 8 months and never saw any ill effects.

[matt325is]

I have NEW stock dual valve springs for i heads in my garage taht I would be willing to sell. Forgot how much they cost at IE, but that is where i bought them from, I'd be willing to really beat that price.

matt

[Jand3rson]

I have NEW stock dual valve springs for i heads in my garage taht I would be willing to sell. Forgot how much they cost at IE, but that is where i bought them from, I'd be willing to really beat that price.

matt

You've got PM.

274 is a good compromise for a street car. I've heard that once beyond this, idle goes to hell.

What's the complete ratio, 274/?

[BS87]

I have NEW stock dual valve springs for i heads in my garage taht I would be willing to sell. Forgot how much they cost at IE, but that is where i bought them from, I'd be willing to really beat that price.

matt

I think its around $10 for an individual set.