350hp at the crank to 280rwhp is 20%.

Average is 15-18% with a manual and a solid axle. Average auto is around 20%, maybe 22% or so if you have a loose stall. Throw in the vette rear end, I would say 25-27% loss MAX with all accessories and exhaust. Not sure where you are getting the 30-35% from but...thats VERY high.. GM Hi Perf mag dynoed a LS2 crate motor stock with headers/water pump and it made 430hp on an engine dyno. All new LS2 GTOs dyno around 350-360 rwhp with a manual and independent rear suspension. GM is rating the LS2s at 400hp so... Its pretty close at 15-20%

If you are losing 30-35% in your drivetrain, there is not much point in even trying to build a motor thats going to make power...it would be pointless...just drive it stock and slow like mine. LOL

 

You couldn't pay me to put Edelbrock heads on. You're paying for nothing but a name. They make good intake manifolds and dress up crap. That's about it. The Trick Flow heads flow nicely and are rated pretty good in terms of bang for your buck.

 

450 crank HP is around 360rwhp in a manual. Ball parking it.

400 crank hp is around 320rwhp in a manual. Thats basing it on a true 20% loss(x .80) but depending on how much the vette rear end really kills, that number could be a little lower. Also your exhaust will play a BIG roll in RWHP. If you are making 450hp at the crank and dump it into 2" exhaust and turbo mufflers...don't expect good RWHP. Do everything you can to minimize your loss from your crank HP. Good headers/exhaust, fresh drive train lubes, maybe electric fans. Also a good clutch is a must in a manual.

 

I'm running a cast internally balanced eagle crank, Forged 6" eagle rods, SRP forged pistons, AFR195s, Victor Jr. intake, Comp Cams 236/242 billet hydraulic roller, 1.6RR....puts out an honest 500hp on engine dyno. Very street friendly...cost..not so bad, your looking at around $5500-6000 at the most..depending on how much you do yourself. But like stated in another thread..build once and build it right...it took me 2 383s to figure that out...and yes, i was going through this being a starving college student too...so it can be done.

 

I'm not talking about just drivetrain losses, I'm talking total losses from engine dyno (w/ no accessories and only headers) to RWHP. I guess 30-35% was a little high, I was just basing that figure on a couple things other people had told me. I guess what I had read before overstated the difference from gross crate motor ratings to crank hp in the car. Thanks a lot for the information though!

 

That is a damn good street combo right there!

 

Yeah, I know all of that. I believe I'm running 2 1/4" exhaust right now, but I'm putting on sidepipes as soon as I can, so it'd be pointless upgrading before that.

Redshark, thanks for all the tips...but honestly, that much money on just the motor is a bit more than I'd be willing to spend. If I can get above 325 at the wheels I'll be happy, 340 or above and I'll be very happy, especially given how light these cars are I know I could just save up more and build a nice forged set-up like you have...but for the extra money, I'd rather throw on some sidepipes. Badass combo though!

 

www.ryanscarpage.50megs.com/combos1.html Over 100 Dyno Proven street combo's. Will give you lot's of usefull information. I had to save this for all the people that ask this same question.

 

Whoa! Thanks a ton for the link

As far as the Trick Flows go - in that Chevy Hi-Perf article, they had them on a 383 with a Comp 274H (230/236 @ .050 and .487/.490) and made 455hp@5300 and 496lb-ft@4000! Average hp was 377, (303 @ 3,300) and average tq was 428 lb-ft (482 @ 3,300). Those are some damn healthy numbers to me, and considering the 465hp package is basically the same with a significantly higher lift cam, I'm definitely inclined to believe their figures. I may still go with the 420hp package, but just thought I'd post this up...

I'm definitely keeping T&L in mind...I'll actually have more like $4000 to spend, so I should be able to have them build a slightly more powerful motor. The more I think about it, the more I feel this might be the way to go...they have a 425hp motor up on eBay for $4000 right now. Factor in a couple hundred dollars worth of shipping - I would spend about as much getting my own 383 built with the Trick Flow 420hp package, factoring in the estimate for all the machine and assembly work from a local shop around here. Having a warranty and a package I know works is a huge advantage too.

Thanks again for all the advice everyone! I'm going to give Lloyd a call tomorrow and work out some figures, but it really seems that getting one of their engines will be the way to go.

 

Give these guys a call

http://www.masperformance.com/

They built me a nice 480 HP 383

Plus they're not that far away.

 

I did much the same except it is into a new bowtie 4 bolt block,the heads are worked Brodix track 1,the intake is rpm airgap....i have a flat tappet cam,huge torque slightly lower rwhp,349 which seems plenty at the moment.....i have plans to install a fuel injection system which will prob generate about 390rwhp and still keep the torque up;but it was anything but cheap..not game to add it all up but it was more than $10,000.....john

 

Man...not to disillusion you, but how the heck did you end up putting $10k into a motor that only dyno's 349rwhp? For that money you could've bought an LS6 and T-56 to match Now, note that I definitely prefer old-school carb'd motors in old-school cars like these, but just for reference...

 

New bowtieblock,new 4340 eagle crank,new 4340 eagle h beams,lt weight srp pistons,bowtie racing caps, file fit rings,all the maching necessary,several thousand dollars worth of head work, one piece chr-moly pushrods,dual valve springs,shaft roller rockers,valve work,new inlet, new carb,remote oil filter and cooler and goodness know how many other little things thatadd up to lots of dollars...john

 

if you want about 340 at the wheels...alittle more than 400hp at the crank on a 383...you could get some decent heads and even have work done on them..as long as they are around 190-200cc. Get a good flat tappet cam, hyper pistons, and your set...it wouldn't take much to get that..just most of your money will be in your heads, because thats where your going to get the power...but you mentioned 450-460 in your first post..and those numbers respectively, are going to take more cam, better flowing heads..yaddy yaddy yada...you know what i mean.

 

I was in the search of more horse a couple months ago. Here are my results.
I got this setup:

http://store.summitracing.com/partde...5&autoview=sku
The fit was nice and the parts seem great. Very straight forward install with decent instructions. You will need rockers.

I was told trick flow has some nice stuff also. This is theirs that compairs to the holley:

http://store.summitracing.com/partde...5&autoview=sku

But there is no intake manifold on the plus it comes with the rockers.

Finally here is the edelbrock:

http://store.summitracing.com/partde...5&autoview=sku

They seem to be a well know company but the set doesn't include timing chain set or pushrods. So you'd have to measure those and get the right ones.

Those wil all put you in the 400 - 425 hp range. But you have to look at the cams and see if they meet your requirements for how you want the power band.

 

Yeah, I'm thinking 450-460 might have been a little bit high for the budget I'm working with. 340-350 at the wheels is fine for me, that'd get me well into the 12's on some good tires, so I'd be on par with new C6s

Honestly, the more I look at it and think about it, the more I'm leaning towards getting a crate motor from T&L. I was speaking to them just now and they really seem like a great group of people - they'll even tune my carb for free if I send it in! For just under $4000 I can get a 425 or 450hp motor, depending on how far I want to go on the cam - this would even be with a hydraulic roller set-up. That may be slightly overkill, I know, but if it gets me the power I want within my budget along with the other benefits of a hyd roller, I'm all for it Of course, the money may be better spent porting the heads and intake instead, but I'll talk to them about that...

I called a local engine shop and at a minimum I would need to get all the machining and bottom-end assembly from them (I could build the top end if necessary). They said $800-$1200 for that, or $1200-$1500 for the entire assembly. Factor in $2650 for the top end, $1000 for the bottom end, and I'm looking at $4000 or so for the complete engine...for the same money, I can keep my matching numbers motor (maybe sell it to the right person?) and get a motor that's every bit as capable, dyno'd so I know exactly what to expect, and has a 1 year warranty. Sounds like a great deal to me...

 

4 grand for a crate 383 with a hydraulic roller...well worth it..what kind of heads are on it?

 

According to their site, they use (aluminum) Dart Pro 1s...215s, which seems pretty big for a 383 to me, but I am definitely no expert when it comes to head selection, especially for a bigger motor like this. RPM Air-Gap intake - which I was pleasantly surprised to hear - and a custom grind cam. Here's a sample dyno sheet from their website - what really grabs me is how broad that torque curve is, over 450lb-ft at anything above 3k!

 

Man you can't beat that kind of HP and TQ for $4000. Especially since its broke in and dyno tuned, ready to roll when you get it. How much hp is it? looks like 420hp or so. That one have the forged bottom end?

Did you talk to lloyd about his 408" $4700 with 460hp/520tq. Thats what he recommended to me if I don't go 496".

 

Yeah, that specific one ended up being 420hp...that's just the sample they have on their site. My guess is that that's with the cast bottom end, because they show it with the base $3595 motor.

As attractive an option as that is, I think the 408 is going a bit beyond the budget I have for the engine mods...I could always wait, but I think I would rather just save up the $700 and put it towards another part of the car. When he calls me back, I'm going to talk to him in a bit more detail about my various options power-wise for $4000. He mentioned one of my options for the hyd roller setup would be to go with the more aggressive cam, 230/230 (the phone cut off before I could get the rest of the specs ), which they rate at 450hp. I'm going to talk to them some more and figure out what I'll end up going with...a 425-450hp crate 383, dyno'd with a warranty, plus my carb tuned to that engine for $4000 is just awesome. I can hardly wait!

Thanks a ton for the recommendation