2 heads 1 option. give your opinion

[260Zz]

alright im kind of stuck and cant decide. i got a good running l28 with e88 head and header and 4 barrel intake manifold no 4 barrel yet still hunting for a 390cfm holley, or in my shed i got a 280z fuel injected head all valves rockers and every thing and cam still intact just needs a cleaning and port/polish mabey a valve grind. i dont know which 1 to do. because im looking at 400$+ with carb and tuning and jets and gaskets on the e88. what would you guys do. "question would the head from the 72 skyline L20 i6 fit the l28?"

[bart628]

I'd suggest putting on the E88+Holley 390 CFM based on simplicity or light modifications. But if you plan to eventually turbo or extensively modify the engine down the road, I'd suggest the 280z fuel injected head which allows you to use MS-II or whatever electronic fuel management in the future.

[MikeBZ]

I'd go with what you have assembled. Maybe check ebay for a cheaper 390 carb. Holley's are easy to rebuild. I think the L20 head has really small valves and wouldnt work on a 2.8 liter motor very well

[dan5138]

If you are handy with a drill press and a carbide burr you can modify the E88 to accept the FI stuff. This is what I did to an l26 I had, and it runs great.

[blue72]

Which 280Z head, N42 or N47?

[ozconnection]

"question would the head from the 72 skyline L20 i6 fit the l28?"

 

Personally, I like the idea of using a small port head on an L28. I'm about to do just that on my car to improve bottom end torque. I have a street car that weighs in at almost 1500 kgs and bottom end grunt is especially important to me.

 

Many will knock the idea. Enlarging the ports is always seen as the 'right' thing to do. So now that idea is so ingrained in peoples minds, any engine with stock ports isn't really serious about making horsepower. Forget about making the ports smaller then...that's insane!

 

As far as tuning is concerned, the small port head will promote air speed through the cylinder head into the chambers and cylinders. The valves are smaller and less shrouded. The compression ratio will rise due to the smaller chambers but this needs verification as some combinations won't work. Sure, a smaller port may be somewhat restrictive, however some minor bowl work and cleaning up of the valve seat area can improve things considerably. My solution is to put in a bigger camshaft if more top end performance is required. But you have to remember the reason for using this head in the first place.

 

I feel that there is a definite lack of experience out there with this concept and L Series engines. Maybe you could beat me to it and tell us how it works.

[Tony D]

It all depends on where your power band will lie with the cam you select.

If you are running an L28 Cam in the L20A head, you will get great bottom end, but be out of breath by 5500. No matter what you do. Those valves are small. But as stated the port velocity of the larger cylinders combined with the well-unshrouded dinky valves will flow that head to it's maximum potential. It just won't be that much.

 

The complete EFI head will make decent horsepower and pull harder on the upper ranges of the rpm range (from 3500 on up) that the L20A head, but the L20A will have a 'grunt advantage'... especially since the combustion chambers are so small, you will have quite a bit of compression. I think that may be more of a limiting factor: compression ratio with the L20A. It will fit, but likely it has Comb Chambers sized for the drastically smaller L20A bore as well, and consequently may have way too much compression for practical driver usage. E31 on flat top block anybody, off the top of your head remember the CR? The Y20 head from a LATE skyline L20E with the BIG combustion chamber is SMALLER than an E31 chamber...meaning HIGHER compression...

 

As mentioned, it's also about your gearing, and what you intend to do with the car...neither of which you have revealed...

[citjet]

I have a Holley 390 that I am selling for 100 obo. It needs to be rebuilt but, as mentioned, is an easy job.

 

http://forums.hybridz.org/showthread.php?t=148701

 

Gratuitous self-promotion I know:D

 

I'm running the same Holley 390 on my L24 w/E88 mildly ported head and I love the simplicity of the setup.