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1st s30, going to build a decent l28


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So I finally got my hands on an early 74 260z. I've had several z31's and an s130 so I'm not new to the z game... I just have some things I need advice on. I received a solid rolling chassis, boxes of parts and one l28 na (n42 block and n47 head) that has an l26 intake and what looks to be earlier SU carbs. I also received an l28t (f54 block and p90 head) that's missing the turbo but not down pipe... I was told both were good engines turbo coming out of a wrecked car with right at 100k, and na being an l26 (incorrect) that was a fresher bottom end. So let me drop in a few pics to keep some attention... Original color,

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Ok now for the questions, I'd like to build the na block with higher compression. I'm coming across conflicting info... Can I pick up some flat top pistons and that up the compression to around 10 to 1? Along with a lumpy cam (not so much to sacrifice power or push it to far up in the rpms). Also some port work on the heads with some valve seats/seals. And of course a full gasket kit, timing chain and bearings if needed. I've read the block is fine to build and the head is an ok flow'er plus I'm not looking for anything wild. I'll figure out what I will do with the l28t later. I'm aware of the potential just have an 88 na2t z31... The usual places for parts are turning up null.

 

Recap,

Pistons where? ITM can be had on eBay, good/bad?

Compression numbers with nothing but flat tops...

Cam suggestions, supporting mods?

N47 tricks?

Parts sources...

My z31

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The ITM pistons are a good stock piston. I've been running them in my turbo engine for a few years now. Yes, compression should be in the 10:1+ range. I like getting mine cc'd to make sure. Just about any bigger cam will require springs because of coil bind, even though they are plenty stiff.

Edited by skirkland1980
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Man you need to do a lot more reading, but you're off to a good start. Here's some more info that should have literally everything you would need to know except for the cam specs.

 

http://pape.ws/allan_and_rosanne/Z-Car_Stuff/Bryan-Little/P79-P90%20head%20modding%20tips.htm

 

I ran an L28 with flattops, late model e88 head (with larger valves), Stage 3 cam kit from MSA, 6-1 headers and triple webers that were rebuilt by top end performance. It was a blast

Edited by BluDestiny
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N47 is open and I know the p90 is a good performer but I hate to rip the head off a perfectly good motor and from what I have come across the p90 will not give me as much compression... Plus I'm thinking of building the turbo motor later when the quest for more power continues... And as far as the warning for no location that's some burro mireda...

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And as far as the warning for no location that's some burro mireda...

 

5. This site is based in the USA, and as such, text is to be written in English. There are web sites available on the web that can translate text from many recognized official languages to English, if you don't know it. (But then how could you read this? ) Gangster-slang, or any other cute, obtuse, street-talk dialects are not tolerated. Write in clear English that does not require a current knowledge of the latest street-slang. Text message or IM shorthand does not qualify as English. Always try to use proper punctuation, spelling AND capitalization.5. This site is based in the USA, and as such, text is to be written in English. There are web sites available on the web that can translate text from many recognized official languages to English, if you don't know it. (But then how could you read this? ) Gangster-slang, or any other cute, obtuse, street-talk dialects are not tolerated. Write in clear English that does not require a current knowledge of the latest street-slang. Text message or IM shorthand does not qualify as English. Always try to use proper punctuation, spelling AND capitalization.

 

 

Please read, respect, and follow forum rules.

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Like the car, what's the next color gonna be?  Keeping the wheels, or changing?  Personally I wouldn't let mine out the garage door with rotas on it, but an amazing number of people seem to like them.  Check the engine forum for answers to your piston questions, there's a lot there on where to source them.  Also, Google search can be used too, the link shows my search for 'flat pistons'.

 

Google Search on HybridZ.org

Edited by RB26powered74zcar
Removed un needed sentence
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Going back with the stock green. The wheels will do until I figure out exactly what I'm going to do with the suspension. I have seen snowflake wheels on late s130's that I might try to get ahold of?

And on another note thanks for the suspended account admin! I really appreciate the roadblock in the research on hybridz. So was I suspended for NOT displaying where I live in the Profile I've had for years? Or for saying it was donky crap (in misspelled spanish) that I had to do it? Because my error was not plainly stated...

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And on another note thanks for the suspended account admin! I really appreciate the roadblock in the research on hybridz. So was I suspended for NOT displaying where I live in the Profile I've had for years? Or for saying it was donky crap (in misspelled spanish) that I had to do it? Because my error was not plainly stated...

 

You were suspended for your resistance towards the rules, and being expected to follow them. Your latest post isn’t any better. Last warning. Make an effort to follow forum rules, without disparaging the staff, or the suspension will be much longer.

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Look I'm not trying to piss off the staff, actually I've seen forums where the admins are MIA, non existant or just couldn't give a $. And trying to research problems or rustle up help is enough to make one mad so I appreciate you guys. Actually one of the main reasons I got rid of my fc! I am here simply to find help / parts and contribute anyway I can, not to cause problems. The location thing after the few years of being here just really rubbed me the wrong way and actually caused me to break rules with my job... Also I didn't realize other languages would be a problem / cause the reaction? And where I'm located you just about need a second language, so I have learned what I need too. Sorry for being a smart Ã**, maybe I just needed cafine or nicotine or both?

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Well you're lucky to have an account, because when the switched to this forum software/format they warned people for MONTHS that if they didn't update their location in their profile then their account would be deleted.

 

 

I understand your frustration, but bad talking the rules never helps anyone.

 

Personally I'm glad they stress putting up your location. There's been several times I've gone to post information for someone, and then I realize where they're located and totally had to re-write my post because I didn't realize where they were. I have members all over the WORLD, not just in the USA and having everyone at least share what region they're in, and having everyone join together with one common language really helps EVERYONE benefit.

 

 

As to your questions, the link bludestiny posted is full of great info, though it doesn't talk much about the N47 head much. Check out this section of the forum http://forums.hybridz.org/forum/90-l-series/ and read up if you plan on doing your own engine work, or hope to not be had by some shade tree machinist that says "yea I can work on that" while having ZERO experience with L or other inline 6 heads.

 

As to using flat tops with a N47, there's no reason you can't do it. Give it enough cam and your timing shouldn't be impossible to set on pump gas. The reason for people suggesting using the P90 is that compression for compression it will yield a much better result. The challenge of course is getting the compression there. This isn't a huge problem if you shave the head, or plan on running a 3+ liter short block.

 

And all that said, ALL of the heads have room for MASSIVE improvement when it comes to flow. There's also MASSIVE amounts of information on this site regards to porting. So much so all I'll say is that you'll want to spend most of your energy on the chamber. Absolutely forget about doing runner porting and that's it. It's a waste of time.

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Well you're lucky to have an account, because when the switched to this forum software/format they warned people for MONTHS that if they didn't update their location in their profile then their account would be deleted.

 

 

We've been asking for years... http://forums.hybridz.org/topic/89218-locking-out-accounts-of-members-posting-without-a-location/

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Well I think I have the beginning formula, breaking it down degreasing & painting... Checking all bearing clearances and the cylinder bores. Picking up the appropriate size flat top pistons (planning itm) And Paired with a 275 duration / 480 lift cam (any ideas)? I will also smooth out the castings of the head and port match. Of course gaskets and bearings if needed. And rebuild the su's with a jet kit... About to check out what kind of jets work well. A decent 160-200 hp?

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