SBC phase II advice

[Rat Fink]

Hello, I'm a "new" member who has been viewing for about 5-7 years, in fact I had a different member name on the "old" Hybridz site back then. It looks like I'll need to change it again, since I didn't know there was another Rat Fink, spelled Ratfink, oh well, sorry Ratfink I'll change it when I figure out how to.

 

Anyway I wanted to introduce the current car and run my thoughts past you guys, especially Grumpyvette if he's reading this.

 

My current Z car: (third I've had, but only one now) 1973 240Z with 350 ZZ4 crate motor, fastburn aluminum heads, Holly 750, 9.6:1, T5, R200.

 

 

 

 

It dynos at almost 300RWHP, 325ftlbs, but I want about 400RWHP and 400ftlbs, maybe more with the occasional shot of Nitrous. I think this seems to be fine for my R200 and 280ZX turbo axles. Need bigger tires, I know.

 

If I go with a built 383 I could get those numbers NA but probably would need really good gas and a fairly high compression ratio and maybe be a little less streetable. I'm thinking of a Weiand 144 blower for those extra 100HP and ftlbs, and a 100 shot of nitrous on top. (If you see Mad Max when you're 16, it can have lasting effects)

 

So my existing low end is not forged and I don't think it'll put up with that abuse. Also the 9.6:1 won't take much boost either. Or will it? I have some guys who have built decent HP telling me that I should just bolt the 144 and 100 shot to what I've got and run it with lot of timing. Redo the low end if/when I blow it up. Thoughts?

 

BTW, I just don't trust my own bottom end work at those high power levels. I won't install a rotating assembly in my block this time.

 

I could spec a 383 crate short block and use my heads. What do you guys think is a good way to build the 383 if I want to add my existing heads, the 144, and nitrous myself? Weiand says 8.5:1, and my friends say that's CYA conservative and 9.6:1 should still allow me enough boost to get the numbers I want.

 

Any opinions on OC/LA speed shops? I've been going to Superior in Anaheim. They could do the whole thing, but $$$.

 

Oh well, any advice would be greatly appreciated, thanks

[jt1]

You have an absolutely beautiful car. Very clean and well done.

 

You can reach your 400/400 goal with any of the ways you mentioned. If your going to run it hard, you'l need to upgrade the bottom end. It will last a while at those levels, but it's days will be numbered.

 

For a NA 383, you're going to need 10:5 comp, pump 93 gas, heads that flow 260/200 or better, 240-245 duration cam, 1 3/4 headers with a good exhaust, air gap intake and a 750-830 carb. It may be a little less streetable than your current setup, but not much.

 

It really comes down to which route you like the most, and want to pursue.

 

John

[grumpyvette]

you can easily get 400 rear wheel hp from a N/A stroker combo with the fastburn heads, and you may be able to do it without premium octane fuel if your willing to put up with a lopey idle , and low vacuum for the accessories.

a 383 or 396 stroker (3.75" or 3.875" stroke) rotating assembly added to your current block is one route, but if your willing to buy a complete short block you can upgrade to a 404-434sbc with a MUCH STRONGER aftermarket block, if you wanted too and gain a good deal more tq/hp

ID strongly suggest buying a short block from

 

http://www.ohiocrank.com/chev_sb_shortb.html

 

add a decent roller cam, to your combo and that engine could get you to the 400 rear wheel hp goal easily

[Rat Fink]

Thanks guys, I didn't do the conversion, BTW.

 

As far as "what I want", well, I want a baby blower. (note the Rat Fink handle and previous Mad Max reference) It's not about "need" and I guess this is one place where everyone understands that for sure. Side pipes are another part of the Rat Fink equation.

 

And what I'm reading from you says my friends aren't all that crazy, I can do what they say (put 144+100shot on my wimpy bottom end) and I'm not all that crazy either (I know it won't last)

 

I'll keep you posted

[grumpyvette]

theres a good bit of HP to be had relatively cheaply with nitrous,(100 hp on a STOCK SBC IS ALMOST ALWAYS NO PROBLEM WITH A WET KIT) a superchargers going to be a much more expensive deal.

you can get even more with a WET nitrous kit and a matched cam thats designed for nitrous use.

 

this might help

 

http://www.chevytalk.org/fusionbb/showtopic.php?tid/49752/

[Rat Fink]

Thanks Grumpy, yeah no matter what else happens, I'm also putting nitrous on, just because I always wanted it (again with the Mad Max)

 

100 shot, the only thing to decide is if I can afford the height of the half inch carb plate or if I should plumb the blower manifold. I'm in the Peoples Republic of California and they don't seem to tolerate blocking much visibility with a hood scoop, the windshield weatherstripping line seems to be the max I've seen. To keep the added height to an absolute minimum, the 144 and an no-choke 750 carb will let basically just the air cleaner extend past the hood, I think I can fab that and keep it to two inches. another half inch for the plate might make a difference.

 

I know the blower costs more, but it sticks out of the hood and looks badass and that's half the reason; it's an expensive hood ornament that gives the performance and the look I want, and I won't have to mess with the low end for a while.

 

So I'll bolt the 144 and 100 shot to my 9.6:1 and see how long it lasts.

When it blows up I'll be asking about the 383 compression ratio I should use with the 144 again.

[grumpyvette]

ID POINT OUT THAT IF YOUR DETERMINED TO INSTALL A SUPERCHARGER, the 144 is both far less effective and causes more hood clearance issues than the centrifical superchargers

 

http://www.paxtonauto.com/

 

http://www.procharger.com/

 

http://www.vortechsuperchargers.com/

 

http://airflowresearch.com/articles/article122/A-P1.htm

 

http://airflowresearch.com/articles/article119/A-P1.htm

 

http://airflowresearch.com/articles/article077/A-P1.htm

 

http://airflowresearch.com/articles/article016/A16-P1.htm

[Jerminator96]

I say go for the blower. It's a simple solution and it looks awesome!As for your compression ratio, static CR doesn't really mean anything. What matters is cylinder pressure and dynamic CR gives you a better idea of that. For what it's worth, the Kawasaki ZX14 guys are running turbochargers on their stock 12.5:1 setup and doing it with pump gas! If you want your motor to survive then worry more about your choice of cam and your timing/tune.

[Rat Fink]

Grumpy it's not about hood clearance, I want it to stick out, but just a little to keep it legal. If it stayed under the hood I would just go N/A. Aesthetics want to be Ed Roth goes to the Country Club.

Cross between what I got and:

 

I don't know if that attachment will work I'm new at this

[COZY Z COLE]

 

 

 

I lived in Fairfield,CA. and from 2002 to 2007 when I moved to TX., I never had a police problem with my large cowl hood, sidepipes, or having my front lic. plate in the windshield... I have a 355 SBC / a 144 Weiand blower.

 

BTW I would not go over 8.5:1 CPR..

 

LARRY

[Rat Fink]

HA HA! Now that's what I'm talking about!

 

I'd be a bit more subdued than that, Cra...uh, Cozy Cole, but it's great to hear you got away with all that height here! I do drive through Irvine, but still.

 

So you say 8.5:1 too, that's what I hear mostly, but what do you think would happen if I keep boost low minimal and bolt on to my 9.6:1? I'm not asking for much HP. Some say go for it. If I have to do 8.5:1 then I gotta do the whole low end, which of course increases the scope of the project.

 

Then I might as well sell the whole motor turn key and swap in the 383+144.

Anybody interested? I guess if I get more serious I'll post in "for sale".

Starting to sound like an easier project, but more $$.

 

Hey thanks JT1 and Jerminator.

[jbk240z]

What a cool idea, Rat Fink style! As for engine advice, I would listen to what Grumpyvette and the like are saying. I never even met or even emailed Grumpy, but I think he knows his stuff. You might try to contact dr-hunt and turbomeister, they are worthy V8 guys also.

 

This next idea is indeed a crazy one. How about ditching the front suspension assembly and running a straight axle setup. Then jack up the car a bit, blower sticking through the hood, and your set. Just think a '60s gasser style Z, rat fink indeed!

[dustin280zx]

HA HA! Now that's what I'm talking about!

 

I'd be a bit more subdued than that, Cra...uh, Cozy Cole, but it's great to hear you got away with all that height here! I do drive through Irvine, but still.

 

So you say 8.5:1 too, that's what I hear mostly, but what do you think would happen if I keep boost low minimal and bolt on to my 9.6:1? I'm not asking for much HP. Some say go for it. If I have to do 8.5:1 then I gotta do the whole low end, which of course increases the scope of the project.

 

Then I might as well sell the whole motor turn key and swap in the 383+144.

Anybody interested? I guess if I get more serious I'll post in "for sale".

Starting to sound like an easier project, but more $$.

 

Hey thanks JT1 and Jerminator.

 

I have 8.8:1 and i'm going to run 10-12 pounds of boost on pump gas. My brother-in-law has 9.6:1 and he is running 18 pounds. I talked to a guy from alchohol injection systems and he is running 10.0:1 with 10 pounds of boost on pump gas. My setup is turbocharged and the other two have centrifugal superchargers that are blowthrough. I'm not sure if a roots would differ that much on how it raises your AIT. I would get a better crank though because i've read about a couple poeple breaking the snout off the crank (forged scats) with a cog system on the centrifugal.

[grumpyvette]

adding a sizeable increase in ethanol to the fuel blend both cools the intake temps and increases the resistance to detonation,, making those boost levels useable, use enought methanol or ethanol mixed the toulene and you can run even higher boost levels

[Rat Fink]

I have no doubt that Grumpy knows what he's talking about, hope I didn't give another impression. That's why I'm asking, but I think it took me a few posts to convey what I'm thinking about. He knows 100 ways to get the power, but JT1 hit it on the head: "it really comes down to which route you like"

 

You can see there are conflicting opinions on the 144 + my current setup, I heard conflicting opinions before this post (that was the reason for the post) so I'm not surprised. Actually it seems like responses so far are mostly either:

 

"don't do that, it will break" or "sure you could, until it breaks."

 

Which are really not too far apart actually. I'm leaning toward the built 383 with 144. As long as it's from scratch it'd be the recommended 8.5:1. Then I only have the car in pieces long enough for a swap. Lack of time is the reason I could never have done the conversion in the first place.

 

Anyway the idea I have isn't pure rat fink gasser, which would be insanely cool, but I want the car I have paying homage to that era in a subdued way. The only picture I have is in my mind, but let me try a description:

 

There's a hood scoop, but it's low profile, just a few inches tall.

It's forward facing, 60's Hilborn style, but not chromed, maybe ceramic coated to almost blend with the paint.

 

There are sidepipes, but a single 3", not 4 into 1, and again ceramic coated, not chromed almost blending with the paint.

 

There is stance, but not as much as Cole, just an inch, maybe two, bigger in the rear.

 

There are flares, but not bolt on, very subtle, I'm looking at the Subtle Z kit like Juday has.

 

There is horsepower, but only enough to use up the drivetrain.

 

There is polished chrome, but it's all under the hood.

 

Anyway this all could take a while, maybe I'll just keep it unmolested for another year, and I could change my mind in any number of ways until then, Phase I is pretty cool anyway.

[Rat Fink]

Oh yeah, and pump gas only, it's a daily driver

[grumpyvette]

you can easily get a well designed NON-superchharged 383-434 SBC to produce 400 rear wheel hp with or without nitrous and more with nitrous, if your like most of us LACK of MONEY and TIME in some cases are the roadblocks, youll be far better off building a reasonably mild NON-supercharged SBC of decent size with matched parts and gearing the car correctly and driving it that way 99% of the time and only when necessary engauging the nitrous for that extra 100-150 hp boost, why?

the less complicated and the less parts used in the build the lower your maintinance and costs tend to be and the lower your tunning and mechanical skills need to be,its also related to cost vs performance, you can build a killer N/A sbc for under $8K thats going to run for years with few problems, adding nitrous thats rarely used won,t cost much or hurt longevity but a superchargers going to require more up front cost and more maintinance and more up-keep

most PROJECTs get side tracked or never completed due to LACK of FUNDS, or purchaseing (DEALS) on mis-matched components or unrealistic goals that far exceed the available funds and skill levels, in most cases your better off sitting down and making BOTH an EXACT parts list with prices and part numbers and setting a REALISTIC BUDGET and SCHEDUAL to aquire all the components, and machine work.

[Rat Fink]

I hear you Grumpy but years from now, when I'm on my deathbed, putting my whole life in perspective, I could be thinking "yeah, I've had a full life, I had a good wife, kids, career, patents,...and a blown V8 Z". I probably won't be thinking "yeah my one regret is that unnecessary blower"

 

You do have a good point, I am talking about a lot of stuff and the blower complicates things.

 

I got halfway through the budget process, I talked to a speed shop some time ago and had a back of the envelope estimate of just about what you're saying, like $7k NA or $10k with the 144. I'd go into more detail before I really started, but 20 years ago when I started wanting this, I had more time than money, now I have more money than time.

 

The problem I have with the NA383 is that I'm committed to a high CR and could never add the 144. If I start with low CR, then I can add more psi later if I want more power. Maybe the motor will end up in another car that can take more power. Maybe I'll get bored and upgrade the R200 etc later.

 

But yeah the NA 383 would be a whole lot easier, and I could easily nos my existing setup in a weekend or two.

[Jerminator96]

I still think you are attaching too much importance to compression ratio. You must realize that the static compression ratio has very little practical influence on your motor.

 

If you want the 400rwhp now and the potential to add a blower later, then you should consider getting rid of your ZZ4 (or at least the top end) and getting a bigger motor (at the very least a 383) with some great cylinder heads. That way you can build it with a blower in mind and yet make the power you want even without the blower. I ran a 355 built for a turbo N/A for a while and made 385rwhp. It had a 9.5:1 static compression ratio and made a little over 800rwhp with a T-88. It didn't run to it's potential N/A but it was a trade off I made so I could add the turbo later without worrying about rebuilding the motor.

 

For the record I agree with grumpyvette, just build a nice reliable motor and put the bottle to it.

[Rat Fink]

but...but......but that won't stick out of the hood.

 

 

OK also on the table for evil hoods is 280Zone's masterpiece:

http://album.hybridz.org/showgallery.php?cat=500&ppuser=8324

 

Jerm you make a good point, but I didn't think I could do it in that order.

I thought I could bolt on the blower right away and do the nice low end when I blew mine up. I thought I couldn't get the numbers I wanted NA and then go to a blower later. But I don't know too much, just enough to be dangerous I guess.

 

"I still think you are attaching too much importance to compression ratio. You must realize that the static compression ratio has very little practical influence on your motor."

Maybe I don't get it,that's not what I thought. Can you point me to an explanatory link or something?

 

So we know I can do 400/400 RW with NA 383, but I couldn't do those numbers at 8.5:1, JT1 says 10.5:1, you're close at 9.5:1. And you think I'd be able to SC that later? I'm confused.