Input on power gains by swapping head.

[Chickenman]

3 hours ago, moelk said:

Engine only has 3000km since it was built so i won’t tear it apart and do it again ; )

Would be fun to test that combo.

Dony get me wrong, the engine is great and really goes well.

But i like to know why people call some heads bad and some the best heads when there’s no good documentary? At least I can’t find any.

When my engine was built the builder built another L28 engine at the same time. It was a F54/N42 combo with flattops, same cam, same carbs, a Mallory ignition (I have a zx ignition).

He has a canon intake, I have a Harada shokai.

My cars feels faster, both me and him feels this way. Guess it comes down to the intake?

 Could be something as simple as the Ignition curve that makes the difference. Hard to quantify. 

[moelk]

1 hour ago, Chickenman said:

 Could be something as simple as the Ignition curve that makes the difference. Hard to quantify. 

Both engines are tuned quite good.

What I meant was that I thought my engine would be much slower because the 260 E88 head I have, based on what I’ve been reading about that head.

[Zed Head]

As I  understand things there are several versions of the E88 head.  Some have large combustion chambers and small valves.  That would be a "boat anchor" head.  Your head though, seems to be well thought out, with larger valves and a known combustion chamber volume.  You know what you have and it seems designed for the overall engine package.

I've found, in my long and varied history of any type of "bench racing' that people who don't really know what they're talking about are the ones who use terms like "boat anchor".  Once the head has been modified it's no longer an E88 head.  A better description might be that it's an "open chamber" head (to distinguish from the squish type P79 and P90 heads), with 35 and 44 mm valves, and 44 cc combustion chambers.  E88 is what it used to be.

[madkaw]

5 hours ago, moelk said:

Both engines are tuned quite good.

What I meant was that I thought my engine would be much slower because the 260 E88 head I have, based on what I’ve been reading about that head.

I think if you look at the 42 and and the late e-88 you’ll see there’s not much difference in combustion chamber . The N42 has bigger valves . So there shouldn’t be any real advantage with the 42 if valve sizes are the same . 

Did your engine make power on the dyno all the way to 7k rpms?

 

[moelk]

Not all the way to 7000. Cam is to small i guess.

Dyno sheet 180whp/235nm

Edited August 16, 2018 by moelk

[madkaw]

I’d go with a better chamber designed head - p79,90, MN 47 and bump compression to 11.5:1 and go with a bigger cam . 

[moelk]

Well, new (more aggressive) cam has been ordered and i will stick with the head i have and get it ported/worked on during the winter. 

 

 

 

[Jason240z]

what cam are you going with?

 

[moelk]

4 hours ago, Jason240z said:

what cam are you going with?

 

A Don Potter grind cam from Steve Bonk.

535 lift.

[Jason240z]

26 minutes ago, moelk said:

A Don Potter grind cam from Steve Bonk.

535 lift.

what duration?

[moelk]

5 minutes ago, Jason240z said:

what duration?

Don’t know, cam is being made at the moment and more specs will be given when it’s done.

Have heard very good reviews about this cam so i took a chance even if the specs aren’t given before you buy it (just the lift).

And the seller Steve Bonk is a very good helpful guy to so im sure the cam will be great for my needs. 

 

[gundee]

On 8/14/2018 at 7:11 PM, moelk said:

I have a L28 engine bored 1mm with flattops, triple 45s, Schneider stage 3 cam, header etc...

 

Schneider shows 9 different cam grinds for a L6 Z car. What is a stage 3 cam? People throw that term around all the time like it is some magical grind.