e88 and n42

[zman525]

i have 2 engines right now. ones a 1976 l28 with an n42 head and 150k miles on it. I have a 1972 l24 with an e88 head and only 50k miles on it. i was tryin to research the difference between the e88 and n42 but i couldnt find alot of info. i was wondering if i were to swap heads what would be best? could i use the l28 engine with the e88 head or would i lose hp from using the n42 head i have now? the n42 head has a bunch of noise coming from it and needs a total rebuild if i were to keep using it, the e88 head was as quiet as a mouse. whats my best bet here? ive got a weaker engine with less miles (l24) and a stronger engine with high mileage(l28) what shall i do to get the best from both worlds?

[240ZMan]

A few thoughts:

- 150k miles on a Z engine IF it was well maintained (regular oil changes, etc.) isn't a lot and it could still be strong.

- The N42 head on an L28 with flat top pistons (which is what was in the 76) is a very good combination. I can't see any reason to swap the E88 head.

- The noise you describe on the N42 head could just be that the valves need adjusting. Have you done that yet?

- You haven't told us anything else about the rest of the engines such as condition of carbs for the L24 vs. condition of the fuel injection system for the L28. I'll assume that they are both in good condition.

My recommendation is to adjust the valves on the L28/N42 head and check its compression. If it's good, that's the engine I'd use. If you find it's poor, let us know the details. The next step would be to assess if the top end or bottom end is the problem. I wouldn't just start swapping heads until I knew more about the conditon of the rest of the engine.

[Arne]

E88 has smaller valves, and (unless it's been previously rebuilt) will not have steel intake seats.

[texasz]

Check out ZGarage at http://www.geocities.com/zgarage2001/engine.html

[zguitar71]

Stay with the N42.

[240ZMan]

E88 has smaller valves, and (unless it's been previously rebuilt) will not have steel intake seats.

Arne, my memory may not be too good here, but don't the N42 heads also have brass valve seats?

[zman525]

alright it sounds like the n42 is better from what u guys say and searching around.. I have dug into the valves and adjusted them after one of the rockers (i believe it was the rocker, happened ahwile ago) came off. it made it a little better but i still heard a rattly noise coming from the timing chain area, but everything seemed tight sound when i opened it up. another thing i wasnt sure of is the compatibility of the SU's on an n42 head but i guess after researching u can just use a e88 intake manifold gasket to cover up the injector holes. i was reading through one of my MSA catalogs and i saw one of the cam kits. Im thinking about purchasing the stage 3 if im goin to rebuild the n42. Any feedback on this kit, or has anyone run it in an n42 head with SU's?? i would still need to get the valve guide seals and timing chain kit too right?? sorry for the bombardment of questions but i really want to know alot on the area before i start throwing money around...

[Arne]

Arne, my memory may not be too good here, but don't the N42 heads also have brass valve seats?

You know, I think you're right.

[zman525]

i was just reading that web page u had sent me texasz and it showed that the n42 and the e88 made no compression differences on that chart. Also my Z is a california Z and it came with a catylitic converter, and on that site it said that the valves were different on the 280z's with cat's than on the 280z w/o. i have recently got rid of the cat. and also that page said that the l28 from 75-77 came with dished pistons instead of flat top like u said 240z man. so what in the world am i dealing with here? ohh yea it also says that the 76 ran leaded fuel, however mine doesnt....

[240ZMan]

I'm running an N42 head on an L28 with flat top pistons. I recently had my cam and rockers reground by delta cam and have been thrilled with it. The specs are .480" lift with 284/284 degree duration (forget what it is at .050 lift) which is similar I think to the MSA stage III. But this way I still have the benefit of the nissan cam and its hardness and it was way cheaper. I just had to replace the lash pads. The new cam is so quiet now that I have the wipe correct. Coupled with the triple webers and it's a blast to 6500, will pull to 7k easily. Of course, it's a little flat below 2500 rpm, but with 4.11 in the rear, that problem was cured It idles nearly perfectly at 750 rpm, no lope at all.

I'd say that if keeping the engine "streetable" is a priority, this is a great comprimise. If you want more track oriented, this cam is too small.

[zman525]

what was the cost on that? and do u think i would get the same performance out of my l28, even though it suposively has dished pistons?

[240ZMan]

The regrind including rockers was about $120 and the lash pads $35 IIRC.

I forgot that the early L28s had dished pistons. I've heard that big cams like higher compression, so you might see more of a reduction in low end torque. But I doubt it would be huge. I'd suggest you call delta cams. They were really easy to work with, and said they had done a lot of Z regrinds. They can probably help you with the trade off due to lower compression.

Regardless of what cam you go with, I think you're better off getting your cam reground than buying a new non-nissan cam.