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building a hot street car


AZGhost623

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I dont have any reason Im not going that high up to 7500-8000 rpm its just that I dont see a need to or afraid of something failing at that high of rpm. But I know if I do, my DCOE 45's can more than handle it along with my ARP bolts and MLS gasket.  I would be more than estatic if I got 250hp or more out of my setup after all this headwork, however that wasnt primarily my goal, just to have more oompf...

 

I recently managed to get a set of used high compression 89mm Kameari pistons for a 3.0L setup for a 100$ in near new condition. Ill get some FJ20 rods, and just pack it all away for a rainy day when I am ready to tear the block apart in a few years perhaps.

E production z's make 250 flywheel all the time.  That's on 2.8 12:1 .500 and "stock" SU's.  No reason you can't do that with no race restrictions and triples.  Don't ignore the Header.

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For the street just get 10:1 Cr i say and use a L24 crank to get quicker RPM response , The motor i been day dreaming about L24 with L20A crank with long rods and thin forged pistons with E31 or early E88 head CNC/ed to perfection all in the hopes of building a L6 to hit F1 sounds, Being a recluse and a neet that plays video games and watches anime all day i know this may never happen or it will take tons more time the day dreams are great.

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The crank has absolutely nothing to do with what most people think is crankshaft related response.

 

Giving up torque advantage is always a bad idea.

 

"Slow revving l26 & L28's" are FAR more a function of rotational mass and camshaft selection than any perceived crank-arm length change!

 

The dream engine you have in mind will fall flat compared to a properly cammed L24, unless you're willing to run 5.36 gears and 4,500 at highway speeds, with a cam that gets mushy below 5,000.

 

Rest assured that same engine running L24 internals and cam will be far more the beast and make more power EVERYWHERE! You don't need to tell us you play too many video games.

 

(L20A Engine Builder that made 205hp at the rear wheels at just under 9,000 and needed 9500 shift points to keep accelerating.... Check out DemonoidCFH's YouTube Channel and "9500 shift points"---I don't play video games, I make 10,000+ rpm L-Gatas)

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Gah... I talked with Dave in length today, and got the scoop after he checked everything out on my head.

 

So many problems he found, and I told him to fix it all carte blanche. Should be a few weeks before I get it back. I have had this head in the hands of a few backyard mechanics here in town. I realized at the last backyard fix that things weren't being measured or being paid attention to. It was just being put together to run...I get the feeling thats what many backyard guys do around here for just a daily street driver. So that comes in line with him finding out lash pads are all over the place, as well as cam not being centered correctly, valve guides being eaten up, and other problems. I am definately paying twice for the mistakes of many now! Lesson to be had here, is when your doing something make sure its all the right size, and you measuring things out to make sure the cam lobes are correct, wipe pattern, and cam towers are all lined up. Make sure you have the right sized cam for what you want to do, and if in doubt have your cam profiled! Do the job right the first time and you will save money in the long run. It helps to read read read, as Im paying the price now and I should have said something before to these backyard guys but I trusted what they were doing. Sure it ran, but I kept having problems over and over again.

 

So with his new special valves, guides, lash, and his cam, along with big intake port and rest of his head modifications for valve unshrouding and doing the valve pockets its over what I expected to pay...In the end it will be worth it to know its properly setup by a professional and I shouldnt have the problems I previously kept running into. Its also worth it because of the HP numbers he knows Ill be able to make easily which is surpassing my expectations! 

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"It was just being put together to run...I get the feeling thats what many backyard guys do around here for just a daily street driver. "

 

You don't say?

 

"Do the job right the first time and you will save money in the long run."

As Gene Berg told me long ago, and his familiar refrain: "If you don't have the money to do it right now, when will you find the money to do it over?"

I was in the same boat on my VW....countless 'professional' shops attending to my daily driver because I was too busy building performance motors for other people. I simply ASSUMED they were doing all the same checks as I was and simply had bad luck. Gene changed my mind on all that, and one shop here in SoCal did my mild build when the thing got a rod knock on the way home from work after the throttle stuck.

 

In 75,000 miles of driving since, not a sneeze, cough, or fart from that engine! And for a VW in a Bus that is saying something...especially the way I drive. No, it's not capable of turning 15.50 like the turbo engine I had in there...but it gave me exactly what I needed: reliable daily transportation to do my job and pick up Z-Parts at the PNP!

 

Having recorded the price of the countless 'get by' jobs I'd done....the single overhaul was cheaper by a factor of four. That's right...over four years of ownership I'd spent close to 4X what a single overhaul would have cost me where I ended up having it done.

 

After that.... I did all my own work. Or paid the price to have it done right.....the FIRST time!

 

Keep us posted on the results. Welcome to the 'I got bit, too' club!  :icon45: 

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  • 2 months later...

Havent forgotten about this thread, its been 3 long months... much longer than I anticipated..

 

Dave finally has my new head back in route to me. I should get it Monday 2/3, but wont be able to install it just yet... I have to get a custom MLS gasket made due to some measurements I took, and his tight requirements for making sure it operates right within his strict tolerances. I sent him overnight my MLS gasket today so he can shim it up. I am expecting to get the MLS gasket back late next week so I can hopefully install/tune the weekend of 2/8... My cannon intake manifold was also port match to the head, and he blocked the balance tube off. 

 

Ill make sure to post some pictures and eventually some video when its running. The cam he put in it is his 63di which is a tight lash cam .007 with 487 lift, and 280 duration. Super performance for a cam with under a 500 lift he said and real good for a street car. Ill be able to provide a parts list of everything that was done once I get the invoice.

 

Very excited! Cant wait!

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Its also worth it because of the HP numbers he knows Ill be able to make easily which is surpassing my expectations!

 

What kind of numbers are you expecting?

 

Subbing to this thread... Really interested to see what kind of power your motor makes, and if you'd be willing to share, about what it cost you to get there. I have an N47 head that's been ported and polished (but I don't know to what extent) that I think I'd like to modify a bit more - I'd like to see 250hp at the crank.

Edited by rturbo 930
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Everything is just speculation at this point because he doesn't really know numbers with a semi stock block with his cylinder head work like I mentioned in post #34. He gave me numbers on a 240Z stroker that was over 300hp with this head at flywheel. Getting 250hp out of this with my existing mods he speculates will be no problem which was my expectations. Going with group consensus all the power is locked up in the head is what I plan to show. My game plan behind this is to just have the head work done without any balancing of the internals. Get it properly tuned via a dyno and show what is realistic. Then later this year or next, get the internals balanced and re-dyno to show the value on it. Doing it in stages should show realistically what you can expect. My assumption is with the few things I have done, it should be easily then comparable to know going from stock block (semi stock) internals to a 3.0L+ we can then easily tell the difference between the difference stages between each mod.

 

As far as cost goes... my situation was a bit unique. I knew sending it to him he was going to find loads of problems and he did which required extra work. He still charges the same amount that Rob240z showed on the previous page on post #28 which is what was originally quoted to me before he got it.

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  • 2 weeks later...

So here is the rebello head. What suprised me, is that little work looks to have been done on the porting of the intake/exhaust ports, but the throats are all opened up. A Standard gasket fits, doesnt need to be modified. The cannon intake manifold has also been modified, and has had its throat opened up quite a bit to match my DCOE 45's. The intake manifold also had its balance tube modified to block it off between the intake ports.

 

https://imgur.com/a/eTHcr#0

 

New Supertech intake valves

New Supertech valve guides

New Supertech springs

New Supertech spring seats

New Datsun Exhaust valves

New Viton Valve Seals

New Lash pads

New weight matched rockers

New rocker posts (didnt like the old ones)

New Rebello Cam 63di 487/287 - tight lash setup at .007

Cometic MLS Gasket .055

Port work, valve unshrouding

P90 Cylinder head previously shaved .080

ARP Kit

Valve cover gasket

Intake/exhaust gasket

 

Should have it running tommorrow. Dont know how drivable it will be, ill have to retune my carbs for sure. My head was a mess from being poorly put together by the original builder, and then myself and others trying to fix it here and there. Rockers kept falling off when driving it at high rpm. I had enough and sent it off to get properly fixed. Dave mentioned it was typical, but required a lot more work than originally quoted once he saw it. Original quote was around 1400$. Once he saw it, and the condition it was in it ran me way north of that.

 

Im not worred about the block part of it. its got about 500 miles on it since its rebuild last year. Time will tell tho... you fix one thing, and then something else happens... Never had any issues on the block side, its just been all with the head. So I think Im on the right track here so far.

Edited by AZGhost623
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  • 3 months later...

Update on anyone still following this. Unfortunately I ran into some issues and had to send the head back to Rebello, and Dave wanted my block as well. So off everything went. I wasnt able to get it dyno'd with just the head porting like I had originally wanted. Basically the previous builder who I bought this from did not in fact deck the block like it says on the build. So when dave was done with the head, he of course straightened it as part of his process, and then no longer fit onto my block. I had to use an MLS gasket to get the proper height from Dave's recommendation, and with the slopes/valleys around the water jackets on the block it just wasnt going to work. leaks everywhere... So after talking to him while he had everything, I had him build up a 3.0L. It was dyno'd this morning, and is being crated up to ship back to me.

 

Pretty flat torque curve with a peak of 264.5 at 5200 and total hp all in at 6500 with 297.3 hp. Im assuming 240-250hp-ish after parasitic loss at the wheels... Should be a deathtrap on wheels at this point LOL

 

http://i.imgur.com/EUHwdpv.jpg

 

Invoice/Build sheet shows: 

Grind Crank and Stroke .040

.040 Rod Bearings

.010 main 

240Z Rods /w arp

89mm bore

Cast Pistons

Boil Bore & Hone

Deck block and cover

size rods and pistons

build short block

dress engine

set cam timing

pressure test

Edited by AZGhost623
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  • 1 month later...
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  • 9 months later...

N20.....streetable and will kill a vett.build it right,dont forget the z32tt transmission swap,r200 diff,good grade bolts,steet drags,if done right,it will NOT hurt your engine.do your research on timing control and spark.go with a multi port injection WET kit with WOT switch.msd makes a great n2o switch so when you floor it with the bottle on,it wont spray till around 3500-4000 rpms.

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