E88 on L28

[san_maru_zed]

I bought an E88 head from an L24E today, and Im looking at putting it on my L28(FI). I couldnt find an N42 anywhere, so I have to deal with the E88. I've got a few questions though.

How is the 'modern' E88 different from the old ones from 240z(other than the FI notches)?

Is it hard/possible/worthwhile to put the valves from my N42 into the E88(do the E88 heads from the skylines have hardened seats?) ?

Im going to run it with an F54 block which currently has dished pistons, although I bought some flattops which I was planning on using with the N42 head. Can I still use the flattops with the E88 without the valves puching holes in the pistons?(I noticed the L24E pistons had the top of the piston machined for valve clearance). I would be using premium unleaded and a slightly bigger cam....

umm...anything else I should be considering ?

Cheers

Ray

[biker]

This is info that I have come accross on the difference between the two versions.

The E88 came on the 1971-73 240s and '74 260s, in 2 versions, small valve and large valve on the 260. It's chambers are the same cc size as later N42 and 47 heads.

Regards

biker

[dspillman]

Ray,

check your E88 head chamber size compared to PICS on Zcar.com PICS of E31....There are some Small chambered "E31 like" small valve, E88s as well.

Competent machine shop can install your larger valves to early heads........with 280 no block modes needed,but w/240/260 will need to notch block for valve clearence .

david

[JMT240KGTR]

Ray are you in Australia???

If so the E88 off the L24E you refer to has smaller combustion chambers than earlier E88 heads ie 260Z, early Skylines, etc.

I've been told and since verified the volume is around 41-42cc's and have performed the same modification to my L28 to raise C/R.

These heads also have a inlet valve head diameter of 42mm, only 2mm difference to the N42, which is fine unless you're wanting to go all out and use the motor for high-po racing!

I performed this mod last year and it brought my L28 to life; mind you I'm still running dished pistons so my C/R is around the 9.4:1 mark, but this was achieved by shaving the head .030" which reduced the chamber volume to around 37cc's.

As a cheap modification and first step to significantly improve performance I would strongly recommend it, much easier than fitting flat top pistons for starters and unless you want a heap of more power then go flat tops and triple carbs.

Current specs of my engine is

N42 L28 block w/dished pistons,

Skyline R30 elec dizzy,

Skyline L24E E88 head shaved .030" (37cc) with stock cam

240Z twin carbs

Extractors

C/R 9.4:1

3.9:1 open differential

Ideally I'd like the route of flat tops with the N42 head (10:1 C/R) but all I spent to perform this mod was $250AUD, including new chain, tensioner, gaskets, and time cleaning up.

Cheers, James

[san_maru_zed]

Yep, Im in Brissy.

Think I might with flattops in the motor...10.5:1 compression should be sweet

[JMT240KGTR]

I've asked a few guys on this forum and outside and they all suggest that for the street 10.5:1 is probably border line for maximum C/R on the street.

Should be a nice tyre burner!!! :classic:

James

[san_maru_zed]

Originally posted by dspillman

Ray,

check your E88 head chamber size compared to PICS on Zcar.com PICS of E31....There are some Small chambered "E31 like" small valve, E88s as well.

Competent machine shop can install your larger valves to early heads........with 280 no block modes needed,but w/240/260 will need to notch block for valve clearence .

david

I was actually looking at the N42 vs E88 at full lift, and the E88 valves dont seem to protude into the bore anymore than the N42, so Im assuming I wont have a valve clearance issue with slightly increased lift (i.e 0.440) as I havent heard of such problems with the N42...although I would be best checking before firing her up.

Although I am still confused as to why there is valve reliefs on the L24 piston tops (JMT240KGTR has a goof pic of the piston in his gallery).

[JMT240KGTR]

If you can figure out why the pistons have valve reliefs I'd be glad to know as well. In theory you'd assume it's because of a clearance issue but as you've said, there doesn't seem to be a difference.

An interesting one anyway...

[dspillman]

Not sure of engines sold in australia, I really need to study more on datsuns outside the US.....

but with the 73 240, that came with valve relief pistons...pistons had more positive deck clearance 73 model?.... maybe some influence on your piston design as well.

You already no I'm sure, but there is interferance with standard bore 240 w/larger valves.

david