Small block motors

[Al Keller]

Thanks for all of the guidance - I'm going to use a small block Chevy in my hybrid.

Various books and articles have talk about stroker chevy motors like the 383, 392, 402, 406,415,427 etc.

What do you think? I'd like to make about 500hp and 500 ft.lb. without topping 6500 rpm

Thanks,

Al

[Guest JAMIE T]

That kind of horsepower takes a lot of cam and compression(either by combustion chamber size or forced induction.) and its not likely to be very streetable ( I take it you want to drive the Z). Darius's car is a good example of high horsepower and drivable, but his motor would probably make in the neiborhood of 450HP without the Procharger. plenty of people run high compression and big cams on the street( I used to) but it is not as much fun as it would seem. Building a stroker is fine, they build tons of torque, but you can build a 400 smallblock to do that, for less money(if thats a concern). I built one for a guys 3/4 ton 4X4 with 38" tires and it would burn the tires in third gear, and it was a very mild engine with a stick shift. Now if money is no object, just call Lingenfelter and order you a 383 LT1 and a big blower and there you have it. IMO forced Induction is the best way to have very streetable 500+ horsepower and torque.

[Guest pauli]

i throw in my vote with forced induction as well. a blown (or nos'ed) 350-400 would be monstrously powerful and not all that expensive.

[Guest Anonymous]

I think you may be able to do it naturally aspirated. Mike Kelly can probably answer how radical his setup is on the street, I believe he's making 500+ horsepower. I'm told the larger stroker small blocks will somewhat neget the duration a bit so it might be a bit milder than what you'd expect in a engine with that power. JMHO.

 

Lone

 

 

 

[This message has been edited by lonehdrider (edited February 13, 2001).]

[Guest MistaFosta]

Hey, Ill warn you, 500 horse in a Z is a bit unusable...Darius even says that hes got way more than you need...The faster Zs are the 300-400 horse motors, that can grab traction...When your looking at that kind of torque, youve gotta have a massive drivetrain to support it. Trust me, Im doing the same, gotta 450 horse 355 being built, but Im probly going to tune in down so I can get some traction.... With 500 horse, your gonna drive sideways alot...Just look at darius's car..

[Guest Anonymous]

Good point. You would need BEU COUP WIDE tires to support 500 hp. I was playing with Drag SE software (hey it was free from summit, probably inacurate, but this part makes sense) and a good running 350 hp will get the car firmly into the 12's and maybe high 11's if you can hook it up. 11's is a FAST car, hell breaking into the 12's used to be considered pretty damn fast. Consider you goal and needs. Just a opinion, build what you need, but building it way over what you need is expensive if you don't have to do it.

 

Lone

 

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http://www.bent8z.bizland.com/index.html

 

 

 

 

[This message has been edited by lonehdrider (edited February 14, 2001).]

[Guest pauli]

z06 corvettes get mid 12's with 385hp and reasonable gears and 3100lbs+. change any given factor...

[Mikelly]

Well Chris Cloude Rode in my 500+HP z and I'll let him give a more unbiased opinion on how streetable the car was or wasn't. From my own perspective, I can tell you that if you build the motor to have a broad and flat torque curve, and have it tuned properly, put the right sticky rubber under it, and drive it reasonably, you can have a very streetable Z. The only time I ever got nervous driving my Z was if it had rained. The HP and torque would make breaking the rear tires loose so much easier in the wet.

 

Now, I say this, having put fender flares and very wide and sticky tires on the car. That, and a bunch of suspension mods is the key in my opinion. If you run narrow and inferior tires (H or even V rated hard compound) on a poorly engineered chassis you will smoke tires at will without trying.

 

I had no trouble in bumper to bumper stop and go traffic, and the car was VERY drivable in those conditions. Only mistake I made was in when the cam comes to life. My 6th gear is unusable below 2000RPMs, which means I need shorter tires or something gear wise in the 4.+ range as opposed to the 3.7s I'm running. That has nothing to do with my motor design, but more to do with the hydraulic roller cam I chose and that Ed Isky designed based on what I wanted to do with the car, which is run flat out in the desert some day.

 

Again, it depends on your plan, and sticking to it. I'm trying to cruise my motor on the highway in 6th at 1700RPMs and it is bucking... because it wasn't built to do that... My fault, not the combo, because I now am using it in situations it wasn't designed for.

 

Make a plan, and stick to it. As for forced induction, Seems that everyone is way impressed with Darius' car after seeing the video. That car is impressive, but I was more impressed with his bike handling skills. I believe you can get the same kind of performance out of the same type of package I have. A blower or turbo aren't necessary and add complexity and expense to it. True, the wow factor is cool, and I would take nothing away from Darius or his creation, as the car is a work of art, just not the only path to getting to 500 streetable HP.

 

Mike

 

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http://hometown.aol.com/dat74z/myhomepage/auto.html

"I will not be a spectator in the sport of life!"

mjk

[BLKMGK]

I think to make a truly streetable 500HP without the noise and bother of th eblower would be to take a 375horse 350 and add a shot of NOS to it. There when you need it and you can wait until the tires hook to hit the button

 

I've got a NOS bottle here I use as a doorstop and a friend sells the stuff so don't think I'm not tempted to fool with it. I still like blowers better for their "always there" benefit but they're NOT cheap nor are they silent.

 

Honestly, if a 400 or so horse Z can run in the 11's as I know it can, why do you really want 500hp? Is it a mine's bigger thing or do you really feel the need for 10's? It sounds great on paper but it could be a real handful on the street - Darius and Mike can both break the tires loose at some pretty scary speeds with that kind of power...

[Guest Anonymous]

Al,

 

Mike Kelly's car is what I would say is very streetable. No, it's not the kind of car you would want to drive everyday back and forth to work but I don't think that is what Mike intended. For the use Mike intended his car I would have to say he is right on the money. His car is fast, I mean blazing fast!!! It is comfortable to ride in and did I mention it is fast?

 

The one thing that impressed me the most about Mike's car is that it always felt in control. When he took me for a ride he smoked the tires through the first three gears before letting off and it never felt out of control.

 

I agree 100% with Mike's advice, get together a plan and follow that plan. Be realistic about your use for the car. My car is going to be much like Mike's but will have less horsepower. I intend to use my car as a street car and maybe do some autocrossing. It will never be used for daily transportation and will probably only see weekend "cruising" when the weather is nice.

 

I know I am doing some things to my car that are probably "overdone" but it is clearly for the "cool factor". Do I need a 10 point roll cage? Do I need a fuel cell? Do I need 450hp? The answer to these questions is probably not but it is what I want to do with my car.

 

Getting 500 horsepower out of a SBC should be fairly easy. But the difficult question is how long will it last? H beam rods, forged 4340 cranks, lightweight forged pistons, etc...are expensive. At that horsepower level the stresses on the internals becomes pretty severe.

 

Chris

[Al Keller]

All this info is making me think a lot harder than I like to!! It seems like a really healthy 383 could do everything I'm looking for and,maybe, more than I need.

Have you seen dyno results for such a motor? What parts were used?

It also seems that a 383 would use easy to find parts that don't cost an arm & leg.

 

At any rate, thanks for all the info - it really helps.

 

Al

[BLKMGK]

Al, my motor should make between 400 and 450HP. It was built by a bunch of Ford guys out West They had built a similiar motor for one of the work trucks only with 35cubes - it made 425 on their dyno so they figured the same combo at 383cubes would hit my 450HP requirement.

 

If you look elsewhere in the forum you'll fnd my specs. In short it was Eagle rods, Eagle forged crank, Forged pistons - an Eagle stroker kit is what it was That's from memory though so what you see in my other post is probably more accurate since the receipts were right in front of me. The intake is a single plane Edelbrock RPM if memory serves - this was done to kill some low end torque intentionally. The heads are aluminum Edelbrock but there are several competitor's heads that are at least as good if not better. Again my previous post has the part numbers - they're straight plug heads too. I tried to build a fairly docile motor with a solid bottom end for upgrades later on.

 

Some advice - if you go the route I did do NOT worry about buying a one piece rear seal block as I did. The Eagle crank uses the old style flywheel despite having a one piece seal - I had to buy a $250 Centerforce flywheel to work with the T56 anyway (sigh). An older block would've probably been stronger too (shrug). For my HP goals this block should be fine. My cam is flat tappet not a roller. We pretty much decided that the added cost wasn't needed for my HP goal but I DID go with roller rockers. Go with a long pump - pulley selection is better as are brackets than with my short pump.

 

Lastly, if you're on a budget look closely at the GM catalog. Their PM rods are supposed to be stronger than the old GM "pink" rods and are dirt cheap. They've also got some decent cranks in there - you could make one nasty 350 without the added trickery of going to a 383. I think that motor could make as much power as a 383 but maybe not as much torque. I would do forged pistons though no matter what - others may disagree.

[Mikelly]

Al,

Here is what I would recommend:

A: Don't get gucci stuff. I shopped 'till I dropped, and as Chris is finding out, a lot of the high end forged stuff is not recommended for anything BUT drag racing. My builder new I was spending a bunch of money and he steered me away from things like a forged crank, rods and pistons...Why? Because of my plan and intended use.

 

B: Do as Jim recommended and check the GM parts catalog. I'm using the GM PM rods that have been bushed and race prepped, and they were sooo inexpensive. I also have spoken to a Dyno Operator for KB Pistons (He lurks on this Board!) and there are some well known 1/4 mile racers using Hypereutectic pistons on Alcohal! Don't be scared off by the hype against Hyper pistons. They are an excellent alternative to Forged pistons.

 

C: One big mistake I made and will correct when the motor is torn down next winter... Balance the assembly internally. My motor is currently externally balanced. I don't currently shift above 6000RPMs, but the cam makes useable power all the way to 7200. I'll have everything balanced before I ever try and rev it to that range.

 

D: ARP ARP ARP. Use a good "NEW" bolt kit for the engine. more rods fail and cranks wear do to inferior or stretched bolts. Don't take the risk with questionable bolts and studs.

 

E: 4 bolt or 2? doesn't matter really. I have a 4 bolt only because the deal was to good to pass up. But a two bolt block with spayed caps is a good way to go as well...

 

F: Use good zero gap rings. Get a good molley ring set with no gap and get your leak down numbers to increadible percentages!

 

That is exaclty what I would recommend. If you plan to squeeze it or SC this powerplant ALL of this changes.

 

Mike

 

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http://hometown.aol.com/dat74z/myhomepage/auto.html

"I will not be a spectator in the sport of life!"

mjk

[Scottie-GNZ]

Mike, excellent points and I agree with you 120%!!!

 

I do not want anyone to think I do not recommend forged pistons, but I have seen several instances where folks had a goal of 300+hp for a street driver that would see ocassional track duty and were budgeting for forged pistons. IMO, repeat, IMO, forged pistons are not required for an application like that. Regardless of whether or not you do forged pistons, you still have to address detonation. Serious detonation will destroy forged pistons just as well. When detonation is addressed properly, stock or hyper pistons will handle that level of power just fine.

 

To support Mike's recommendation, I have a new set of Federal Mogul hyper pistons with top-notch rings and bearings, ARP rod bolts and head studs. The bulk of my investment and focus is on preventing detonation. Do not think that because I run a turbo the same principles do not apply to an NA.

 

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Scottie

71 240GN-Z

Scottie's GNZ

[John Scott]

All good points. I'd like to emphasize the importance of good rods and bolts to any performance engine. Loose a rod and the rest of the engine is garbage. Note that tensile loads on a connecting rod increase exponentially with RPM. A high hp SC'd load at lower rpm often creates way less stress on a rod than naturally aspirated lower hp at high rpms. At the very least prepare stock rods by the book, Chevy power manual, by magnafluxing, polishing beams, shotpeening, resize balance the whole recip assem. Its not that expensive and well worth the price. I haven't heard the limitations of the PM rods, Chevy claims up to 500 hp. Since you won't have a "matched" recip assem, BALANCE! Racing rods might not be a bad investment.

 

.02 on forged pistons: On naturally aspirated hypereutectic are great! Alcohol engines can run extremely high compression w/o detonation. On a super/turbo charged engine never risk anything less than forged.

 

Scottie, I admire your courage and faith in your engine fuel/management system. Even though you've designed everything to avoid detonation, no system is fail safe or perfect. Just the other day you found you were running a different fuel pressure than you thought. Too far the other way and your hypers would be gone. For $100-150 or so more forged is well worth the price. In a naturally aspirated engine, especially with the low compression ratios pump gas requires, you can put up with quite a bit of detonation before really messing something up. Under boost it can be instantaneous. You may never even hear it. Yes it can destroy both engines, but forged give a substantial margin of safety. If I didn't have forged, I know my pistons would look like whiffle balls by now.

 

JS

 

 

 

 

 

[This message has been edited by John Scott (edited February 17, 2001).]

[Guest Jeff Rimmer]

You've all been talking about this GM parts catalogue. Where might one obtain such a catalogue?

 

Might prove useful in organizing things for my 383 buildup. All in the planning stages other than the block, but if I could use GM parts that might prove to be as effective at a fraction of the cost, I'd be more than willing to use them!!

[John Scott]

Jeff, any Chevy dealer should be able to get the Performance parts catalog. Beware, not all dealers charge the same. I heartily recommend Sallee Chevrolet which also carries a wide range of performance parts in addition to the Chevy line. WWW.Salleechevrolet.com They have provided me with excellent deals that not even the major performance houses can match. Sallee also run a very nice speed shop with inovative engine builds. Check out thier personal line of 383 450 hp ZZ450s. This is personally becoming my favorite chevy source. Additionally, Tom Sallee, parts Guru, is very knowledgeable and willing to help.

JS

[Kevin Shasteen]

In addition to buying a chevy performance catalogue you can also order from HPBooks the "Chevy Power:Official Factory Performance Guide". It contains tips on different builds for the SBC, BBC, 60degree & 90degree V6; also well worth purchacing

 

Dont have a ph# but you can order it from Barnes/Noble or any other book store. All info is GM's, HPBooks was just the publisher.

 

One other note; all you Hi/Po guys out there-surely you know someone who is a GM Employee. When I worked for MIC-a subsidiary of GMAC-which we all know is owned by GM: I could get my parts from the GM Warehouse direct at "Cost" w/out going thru the dealers. In other words, I got my parts at the same price the Dealers did. Dealers will usually mark up a part 70%. Having said that: there are some Dealers out there that want the GM Perf.Parts out on the streets & therefore only charge S&H & sell said parts at a mismal mark-up, yet those dealers are few/far between.

 

Anyway; if you know a GM employee-buy them a Steak Dinner for ordering the parts for you; the only catch is the GM warehouse only takes cash (exact amount) & it must be picked up by the employee who has to show proof he/she is a GM Employee, such as a copy of his/her latest pay check: so this usually means a 1/2 day off from work. Hope you know the GM Employee well!

 

Something to think about.

 

Kevin,

 

PS: Oh yea, one other point; once you have your GM Employee committed; call the GM Warehouse-you have to have the part#'s for the parts you want. What I used to do if I didnt have the part# is call a Chevy Dealer & talk to their parts man; get the part#'s from him & their costs; the call the warehouse & they can tell you if said parts are in or have to be ordered: get the final bottom line cost. Once you have committed-just ask what their procedures are for p/up & you're on your way.

 

 

[This message has been edited by Kevin Shasteen (edited February 17, 2001).]

[BLKMGK]

I'm with John on forged pistons. IF th emotor is going to be NA and not blown or sprayed then by all means go Hyper or maybe even cast (!). Heck, stock GNs ran cast pistons but IMO that's pretty scary (lol).

 

What I have against Hyper is the number of failure's I've seen. Both stock and aftermarket! Hit a little detonation on the bottle or run a tad lean on the boost and you're liable to rattle a ring land right off. One guy I know ran a couple of runs on the bottle with a new set of KB Hypers - he claims it was a safe mixture. Found two pistons with broken lands on teardown. This guy was a BIG NOS fan, sold the stuff, and had been using it for years so he was no punk kid with it.

 

Hypers are more brittle than forged due to the higher silicone and can be run with VERY tight tolerances. OEMs like them because this means less blowby and piston rock (I guess) and that gets the MPG up. Plusses for them but not for those would would bump the cylinder pressure way up with NOS or a blower. Ask any 4valve Cobra guy with a blower - lot's of them are trashing stock pistons (ouch!). The aftermarket ones are supposed to be better and are certainly great for naturally aspirated motors but otherwise I'd be VERY nervous.

 

Scottie - why didn't you go forged? I'm really surprised...

[Scottie-GNZ]

Stock GN pistons are hyper.

 

There were a couple of reasons why I did not go forged but cost was the main driver.

 

I do not race on the streets and NEVER run high boost with pump gas. I occassionally get someone foolish enough to want to try me at a light and just a quick 2-sec spurt with 17# boost is enough to have them searching furiously for that mystery radio station.

 

I have a chip with a 16-pos thumbwheel and each position increases/decreases the fuel mixture 4%, so on the fly (like the SDS R/L knob) I can change my fuel mixture.

 

At the track when I do run high boost, I run no less than 110-octane.

 

The popular GN forged piston is a .030 TRW and I was advised by one of the vendors I highly respect to not use it. He does not even sell it. My other options were a ROSS or JE .020 that were lighter and would require rebalancing. Took me out of my budget.

 

Everything before the piston para is what I mean when I say I focus on eliminating detonation and are things I would do regardless of which piston, as a normal recourse.

 

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Scottie

71 240GN-Z

Scottie's GNZ