big trouble!!!!

[zeiss150]

Hey Z people Looks like I need to rebuild my engine:dead: I had an L24 but im going to jump up to an L28 (F54), so here is my question, can I use an E88 head with out putting the bigger valves in the e88 head and still use the f54 flat top pistons? Has anyone ever done this? Are the smaller valves a problem? Will I starve the engine? If I do need the bigger valves is it just the intake or is also the exaust? Also is it just a matter of putting in the bigger valves or do you need bigger seats?

A couple more questions...

Is flycutting the pistons used just to lower compression?

If I run 9.5:1 CR can I use 87 octaine?

Do all F54 blocks have flat top pistons?

I really don't know what to do... Help.

[frank13]

zeiss150, hey what's up. The Forum for your query whould be better searched in the 240z,260z, 280z Forum under engine. Use the search function with words like F54, head swaps, engine combos. Also try going back all the way to the beginning of the posted threads in the blue bar at the bottom.

Flycutting the pistons. Can't help you on that one. some of the other members that build Motors might.

9.5 C/R on 87 pump gas. As gas stations don't always keep the tanks only full of gas but also alcohol to combat water intrussion in the storage tanks, you taking you chances on melting your toy. It will also depend on the condition and ability of your cooling system. As well as were you set your timing at.

Turbo engines have dished pistons to lower compression.

Help this will help. :devious:

[frank13]

By the way Does zeiss150 refering to a Hassy lens? :devious:

[zeiss150]

Frank wins a prize! Very few people ever get my screen name. Im a photographer and I use my zeiss 150mm lens all the time.

I did a search in the forums and every E88 and L28 combo talked about putting in bigger valves, so I was wondering if that was a "must" or can I get by with the 42 mm valves for an every day driver?

Also if I get an F54 from the junk yard does it have to be non turbo in order for it to have flat top pistons?

Matt-

[Dan Baldwin]

You can use your e88 head. High rpm breathing may suffer, but you'd never notice below 5000. It's still a winning proposition, max power will be greater, but at a lower rpm.

Only F54 non-turbos have flat-top pistons.

You won't have to cut pistons, that is frequently done on stroker builds due to piston pop-up.

If your E88 is a '72, CR will be ~9.8:1. You'll want to use 91 octane or better for sure. The '73 (and '74) E88 gives lower compression. The '71 E88 might give higher compression. I know it's chambers look like the earlier E31 head, but I don't know if the chamber size is smaller like on the E31, or the same size as the '72 E88.

If you can find one, I'd recommend a 280Z N42 head. Same size chambers as the 72 E88, but with the bigger valves.

[zeiss150]

Hey can you use an HKS 2mm big bore gasket with out the big bore? the reason that im asking is that I want to use the 2mm gasket to lower the compression to 9:1 insted of almost 10:1. Am I asking for problems?

[frank13]

Hey zeiss150, man you need to talk to phred and nixcars. Both these cats build engines.

So what did I win Matt? A piece of fine glass optics with the initials C. Z., and made in Austria on it??? Huh, huh, huh????

I'll settle for an A16 or A12 back:D

Or maybe a speedlight for my A2E? :classic:

There is a site I don't remeber the address and I could not find me book mark for it anymore, but it's at geocities. I'm sure if bambikiller sees this thread he'll chime in. I'm pertty sure Carl or one of the others knows the guy I refer to. He has this one page comparing the differnt blocks and heads with pros and cons for different combos, also with the common Z problems. All one one page. Good stuff. Sorry I don't have it handy. If the others don't come up with a link by tommorow i'll look for my hard copy and pass on the link for you. :devious: .

[zeiss150]

here you go frank http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=3802596521&category=15221 The A2e is a great camera. If you want a cheep A12 Kiev makes a back that works on the Hassy V series. I sent phred a IM hopefully he'll get back with me.

Matt-

[Ed]

Originally posted by zeiss150

Hey can you use an HKS 2mm big bore gasket with out the big bore? the reason that im asking is that I want to use the 2mm gasket to lower the compression to 9:1 insted of almost 10:1. Am I asking for problems?

You can use this gasket to lower your compression. Even with that and still pushing 9:1 you won't know for sure if your gonna need high octane fuel. Timing, air temp, and load will all make a difference. If you plan on running this engine for a while I would suggest either getting a N42 head or if your E88 is in good shape have that one worked on (buying a N42 will probably be cheaper if the valves are still in good shape). If you do install bigger valves on your E88 you will also need new seats to match. Do it now while you have the engine out. Flycutting the piston is used when the piston goes above the deck surface. Recesses are cut into the piston for valve clearance. If your worried about the CR get a N42 block from a 76-77 280. They already have a N42 head and also have dished pistons.

[zeiss150]

Ed, I was figuring that I could get away with 9:1 CR because my L24 setup was running 8.75:1 and I was using 87 octaine with no problems at all.

How big of a deal is the smaller valves?

Is it just a high performance issue(6000 rpms and higher?) or will the engine run like crap with the smaller valves(at any rpm)?

The reason im not using the N42 block is I think the CR is to low (8.29:1) and I sort of wanted a little more performance from the engine. am I crazy:ermm: .

Thanks for your help, Matt

P.S. I would be running SU's with SM needles ... sound good?