Build options? Couple choices - very flexible.

[AWDSOME]

Hi,

 

I've been creeping the forums here for a couple of months, but this is my first post. Was wondering if I could get a little help deciding on the best build. I'm sure there are hundreds of these posts, however, I'm having a little trouble finding what I need and I know you are all a helpful bunch so here it goes. I'd like to keep this build N/A and carbed. Overall cost is important, but can be stretched if you feel it's essential. The car everything is going into will be a '71 Z. The numbers match, so I'd rather not completely scavenge parts from the original motor, but I will if I need to because I feel that as beautiful these cars are, they won't ever be high dollar collector cars. I'd rather enjoy it than have to worry about that sort of thing.

 

Here is what I have to work with, yes, I know some of the things don't add up, two of the three engines I have were modified/rebuilt.

 

In my car now

-4 speed

-E88 heads

-'71 block (I assume P30?)

-Round SU's

 

I also have (as of tomorrow, not too late to back out if it's not worth it, although I need other parts from this car):

-E31 head (99.9% sure; I know they're pretty rare)

-P30 Block (2.6L)

-Round SU's

 

This one is a bit of a mystery:

-N42 heads (early years)

-L28 N42 block (early years, higher nickel content?) This block saw boost from previous owner from an electric turbo)

-5 Speed (wide ratio I believe)

 

Also have a couple diffs, believe one is a 3.9 and the other two are standard '71's.

 

 

Any of those combos sound promising? I'd be more than happy to go a 3.0 or 3.1 if I have an applicable combo, I know the early N42 wasn't a bad block for an overbore. The car will be a street car only and needs to run on pump gas. I'd like as much reliability and longevity as possible, but I understand that's just as much in the build itself than the parts used. I like to drive spiritedly, so the car will be ran somewhat hard. What block/head combo sounds like the best, if any? Camshaft that would make it streetable without losing that racecar feel? Torque is more important than HP to me. I can deal with most everything else later, but I need to have a tentative plan so I can start making headway. I spoke to Dave at Rebello Racing and after much deliberation, I've decided to build my own for the experience, but he offered some insight into the 2.7 buildup and the 3.0. Is 200 ft-lbs at the wheels doable from a L28 with headers, triples, exhaust, cam, etc or would it needed to be bored/stroked to get those sort of numbers? Are the stock SUs up to the task or would I need to move to triples or have then bored? As I said, no EFI. I have one modern nightmare and I don't need another.

 

Any help would be GREATLY appreciated! Thanks in advance.

 

Cole

[BluDestiny]

Electric turbo?

 

And I'm assuming you want to stick with the L6? it would be around the same price to swap in a 350sbc if you could get one for the right price.

 

You can get 200ft/lbs with 2.8 with those mods and head work. You can get pretty damn close on SU's. in the 190's close. Still waiting to see what he could do with the triples once he gets them tuned and heads to a dyno.

[duragg]

I just built (myself) an L28 with a slight overbore and N42 head with triples. Still dialing in an breaking in.

But its a cool motor. Growls and pulls cool.

 

However Denver is going to really hurt you with the density altitude. Get the most displacement you can.

 

For me the extra stretch for a stroker wasn't viable. I didn't find any great deals on stroker cranks, and the head gasket required was looking to be pretty expensive too. The delta to get past 2.8L in cost didn't make sense for me so I did the best I could on 2.8.

 

So far my Isky L490 regrind is treating me well. It was big enough to be fun, but not so big that it required tower shims valve cutouts and such.

 

Do your homework real well like you are so you don't get any big surprises.

With flattops and an N42 head they say it puts you in the detonation danger zone.

I haven't hammered the motor hard enough to hear it yet.

 

I also installed a Wideband O2 sensor which is KEY for dialing in Triples.

And installing a KnockSense detonation sensor this weekend.

Slightly overkill for an NA car but these things are relatively cheap.

[rossman]

Get the most displacement you can.

+1

 

I'd go with the N42 block bored out .040 or larger.

 

If the N42 head has injector cut-outs (some don't as TonyD has pointed out in another thread), then you have to deal with that as the stock SU manifold will not seal these up.

 

This block saw boost from previous owner from an electric turbo

Makes me chuckle...

[AWDSOME]

Thanks for the replies, yes, electric. The man I bought the N42 from said it was turboed. I assumed it was the F54 block. I show up, after driving an hour and half to take a took at it, to find this little electric snail on it. Why anyone would go with something that probably saps more power from the engine than it could ever possibly produce is beyond me.

 

Duragg, thanks for the information. It's nice to know someone is building something similar and has confidence in their setup. Displacement at altitude isn't always the best; it takes even more air. My 2.5L NA Subaru routinely kicks higher displacement cars up some of Colorado's 10k+ ft passes. If you can't make enough power to balance out the extra air you need, you're not gaining anything, but it seems like the general consensus is that the L28 is the way to go because you can make a lot more power.

 

Is their anyone on the forum with a built L24, or someone that's using Rebello's 2.7L?

 

So Rossman, if this were your build, given what I have, you'd go with the N42/N42? The head does NOT have the injector cutouts, which I'm still happy about. The two things that are throwing me off about the N42 block are the dished pistons and the exhaust liners. I've heard conflicting answers. Yes, the dished pistons can still have higher CRs and no they can't. I've also heard the exhaust liners can OUTFLOW stock heads without them, but I've also been told they reduce airflow. Have any insight on this? Would flattops for the N42 be a worthwhile investment? I know I said I wanted it streetable so I don't want to even be close to 11:1. You build is great. I know I said that I'd rather not go the forced induction route, but are you on the stock FI or are you running an aftermarket standalone for fuel management?

 

Anyone else like to throw a combo in the mix?

[rossman]

So Rossman, if this were your build, given what I have, you'd go with the N42/N42? The head does NOT have the injector cutouts, which I'm still happy about. The two things that are throwing me off about the N42 block are the dished pistons and the exhaust liners. I've heard conflicting answers. Yes, the dished pistons can still have higher CRs and no they can't. I've also heard the exhaust liners can OUTFLOW stock heads without them, but I've also been told they reduce airflow. Have any insight on this? Would flattops for the N42 be a worthwhile investment? I know I said I wanted it streetable so I don't want to even be close to 11:1. You build is great. I know I said that I'd rather not go the forced induction route, but are you on the stock FI or are you running an aftermarket standalone for fuel management?

 

Cole,

 

All of this has been discussed many times over on this forum. Do a little searching and you will be better informed than you would be based on what any of us can or are willing put in this one thread.

 

I believe we have a consensus to go with N42 L28 block. For the head, I'd also have to research it. I'm no expert, that's why I didn't address which head to use. Are you sure that N42 head has exhaust liners?

 

I'm using a Wolf EMS. Its a fully programmable, stand alone EMS.

[Leon]

Is their anyone on the forum with a built L24, or someone that's using Rebello's 2.7L?

Oiluj on CZCC has a Rebello 2.7L.

 

The two things that are throwing me off about the N42 block are the dished pistons and the exhaust liners. I've heard conflicting answers. Yes, the dished pistons can still have higher CRs and no they can't. I've also heard the exhaust liners can OUTFLOW stock heads without them, but I've also been told they reduce airflow. Have any insight on this?

 

A block doesn't have exhaust liners, a head might. The N42 does not have these, the N47 and P79 do.

[Leon]

And yes, please search. Every question you have has already been answered.

[AWDSOME]

I understand. Thanks for your help thus far. I've read just about every post on the 250+ pages in the L6 section over the last couple of months, but it's always a little more reassuring when someone addresses your situation directly as there hundreds of variables in a build like this, although I don't need to tell you that. I'm just a little indecisive and sometimes hearing it from someone else makes a world of difference. I was hoping I could get Tony D, Mortensen or BRAAP to tune in and drop the knowledge bomb!

 

Wishful thinking I suppose.

 

And yes, sorry. I have an N47 with the exhaust liners on the N42. Also have a spare N42 HEAD. Yes, Leon, the head. Sorry, I have a lot going on. Figured everyone would understand. Assumed wrong. Sorry.

Edited August 26, 2011 by AWDSOME

[Leon]

In your first post you seem to want 200lb-ft out of your engine. Here's the question you have to answer, have you ridden in/driven a Z with 200lb-ft of torque? Have you ridden in/driven a well-tuned stock Z? I have a build thread (with a long first post) here, but I'll summarize some of my experiences, in a nutshell.

 

My early 260Z has an L24/E88 out of a '72 240Z. I feel like this engine is plenty for the car as I use it mainly for street driving, and soon some autocross as well. The L24 with triple Webers and bigger exhaust (stock manifold) put out 121hp and 136lb-ft. There were no carb or timing adjustments made at all. Since we're talking numbers here I'll point out that this was done on a brake dyno, not a purely inertial one like a Dynojet, which inflates power numbers.

 

The car also has a stock '72 cam. With my 280Z 5-speed, I can take off in second gear from a standstill with no problem whatsoever. Torque is strong from 1000rpm all the way to 5500-6000rpm. This can be further improved upon with some tuning.

 

Camshaft that would make it streetable without losing that racecar feel? Torque is more important than HP to me.

 

That would be the stock cam. I haven't felt the need to change out the cam, for now at least.

 

Basically, what I am suggesting is to put together the most reliable and well-tuned setup together that you can. Modifications can always be made down the road. There's no need to go wild, especially if you haven't driven a Z with a healthy engine. If I were starting from scratch with your parts, I'd go N42/E31 or N42/E88 with triples (SUs would be ok too), big exhaust, 5-speed, and 3.9 diff. Make sure your suspension and brakes are fresh as well and you'll have one hell of a fun car for the street and occasional autoX.

[AWDSOME]

Leon,

 

Thanks for all the information. Will read your build thread in it's entirety later today. No, I haven't driven a Z with 200Lb-ft. I've ridden/driven in my fair share of stock Zs. The '71 that everything is in now runs alright once it warms up. It's far from underpowered, I guess I'm just looking for a little more from it. I'm glad to know that you're still running the L24 and feel content with what you have. I'm a purist to a certain extent which is why I'm deciding to stick with the L-series, if not the L24. I've driven some hard core stripped-down performance cars as well as reliable daily drivers (like my Outback Wagon, which can still have some fun). I'm just trying to find the healthy middle ground. Sounds like you're well on the path to locating it.

 

Just from skimming your post, it's a very nice Z. Aside from the dynos numbers listed above and on your build page, do you have any other numbers for it? 0-60, 1/4?

 

Thanks again for all your help. I appreciate it and sorry for being a bit of an ass in my last post; it's often hard to break into forums like this and it's easy to become defensive. Thanks for being welcoming and for the priceless information.

 

Cole

[Leon]

Just from skimming your post, it's a very nice Z. Aside from the dynos numbers listed above and on your build page, do you have any other numbers for it? 0-60, 1/4?

 

I don't have any of those numbers. I don't drag race my Z, I take it for weekend drives and will be starting autocross soon and the car feels very well suited for that. If I had to guess, 0-60 is somewhere in the 7's but that's the "butt dyno" talking. I'm hoping I can extract some more high-end power with tuning, but low-end and midrange are great with my current engine. It's nice to start from a low baseline and work your way up as you go, performing only those modifications you deem necessary after driving the car for a while. It gives a very good feel for what needs to be done and what doesn't need to be done, although usually the former largely overshadows the latter!

 

Re-reading my first posts, I may have been a bit blunt, but the truth is that's how I learned about Z's (or anything else for that matter). I can't even recall how much time I spent researching this stuff, and what was great was that I didn't have to post a single question. I always found my answer when I searched, with the additional benefit of finding other interesting information branching off of my original topic. Each search turned into a spider-web of multiple windows and tabs with great information (make sure to bookmark). The info is out there, and the further you dig, the more gold you find.

[BluDestiny]

That electric turbo is really an injector cooler. So that block [probably] never saw boost. More numbers, my 260z had an L24 that was bored out to an L26 with a e88 head and a stock cam. I made 140hp on a dynopack dyno(bolted directly to the hubs) with rebuilt SU's. Like leon said it exaggerates the numbers a little and does not take into account traction from the tires, so I'm guessing around the same as leon. And that car felt snappy with the 3.9 gearing in the back. It was a completely tame street car and felt awesome. I do not have any trap times or 0-60 times.

 

I need to get another dyno session now since I installed my L28, triple webbers, headers and cam.

[30 ounce]

I live about 30 minutes from Denver and can tell you that displacement will definetly help at altitude. I built a 3.0 liter with Rebello's kit an F54 block and E88 head off my late 260. The head was ported, chambers welded (to get to 11.5:1 compression)and Isky 490X290 cam installed by Bowers Racing in Fort Collins. They also did all the block work too. My cousin, Jim, and I did all the detail work on the block (removed casting flash etc)...Jim did some more detail work on the exhaust ports and we assembled eveything with ARP bolts & studs. I also sent my SU's to Rebello to bore them out. I went 11.5:1 on Isky's recomendation, went with that cam on Brett's recomendation (he did he porting and flow bench work). The thing to remember is that at altitude you lose some dynamic compression and with high overlap cams like my Isky you lose some more. If you don't raise the compression to account for it you'll lose a lot of bottom end tourque and make your engine no fun on the street. The cam, porting & compression should be considered together. I also run pump gas:93 octane or 91 with lucas octane booster.

 

The Z car club of Colorado will be at High Plains Raceway in Byers on September 10th if you want to come out for a ride. Bring a helmet if you got one.

[AWDSOME]

BluDestiny - I feel like a fool. I've never even heard of those before, I just assumed it a way of getting more air into the engine. Do you enjoy your current L28 build?

 

30 Ounce - I've actually had my eye on the 3.0 kit for quite some time. Are you happy with it? I'd love to come out and take a ride. I assume everyone will be there just about all day?

[30 ounce]

I absolutley love this engine. The Rebello kit has a lot going for it like JE forged pistons and Eagle rods that are longer than any of the stock rods for better rod-stroke ratio. It's tame enough for street driving and above 4000 rpms it pulls very hard.

 

The guys and gals start showing up at 7:00am and the track is hot from 8:30-5:00. Boulder Nissan has taken care of the corner workers so we don't have to do it ourselves. A BIG THANKS to them for that. It makes the day go so smooth.

[AWDSOME]

With the 3.0 Kit, did you need to send in anything? I noticed that the 3.0L asks for an exchange and 3.2 asks that you have a good core. Being in Colorado I know he said he'd wave a lot of the core charges because he didn't see me want to have to pay for shipping. He seems like a very reasonable guy. I'll have to just pick up the phone and give him another call about the 3.0 kit. I don't know of any place you can get forged internals and quality parts for that price. They certainly seem to be the "go-to" place for serious performance.

 

You were happy with the work that Bowers Racing did? Do they do machining there as well? I'm up in FoCo/Loveland almost every weekend and it would be worth the trip if I could get a quality shop. Is there anyone there I should talk to in particular?

 

Thanks for the information 30-Ounce. You've been nothing but helpful, as have everyone on Hybrid that I've encountered so far and I'm certainly looking forward to Sept. 10th.

[30 ounce]

I think it says to send in a crank for the 3.0 kit but Dave said not to 'cause he had plenty of them. Dave really knows the L series engines and I wish I had known that he was Antioch when I lived in California. I was less than 20 minutes from him!

 

Bret is the owner of Bowers Racing and does do nice work. I told him to fit my stuff in when he had a chance and it took about 9 month to do my head. It took about a week to do the block though. He is very busy during racing season so...I think that says something. I did have to redo my valvetrain setup. I don't think his miniuns understand the importance of the L series valvetrain setup. No big deal as I wanted to set it up anyway. I've learned to double check everyone's work. Just a good practice I think.

 

I did send Dave my SU's to bore them.

Edited August 28, 2011 by 30 ounce

[BluDestiny]

I like my engine, but I regret not doing a turbo swap. With the money for the cam kit, machine work on the head+install and rebuilding+cost of the webbers I could have had a pretty darn good turbo setup. But every time I hear my car start up and start to pull its orgasmic.

[madkaw]

It will be hard to build an engine with No Regrets. All of us are tinkerers, and are wanting to try something different. I sold off a low mileage turbo motor and now wish i kept it. I did build a strong platform to build on, so I can tweak to my hearts desire. No matter what block you use, it will take a lot of time and tune to see it's potential. Though my 2.4 is mild compared to a lot of these engines on this site- the visceral experience of sound and fun driving of this car keeps me engaged. Start mild then go wild with upgrades. I'm starting with SUs then moving on to Mikunis then maybe a bigger cam or turbo with mild boost and megasquirt.