My friend wants to build a motor for his corvette. He is interested in a 450 stroked engine using either an aluminum block or cast iron bowtie block, one problem is this I have yet to see a 1 piece RMS aluminum block and this could be a flywheel issue since his car has a ZF-6 ...... Now this motor is intended to be run at 12psi, his supercharger is intercooled and he is also running tpis longtube headers, tpis big mouth, tpis 3.5 inch catback, slp runners, 58mm TB. ............ So how would he and what parts would you all recommend for this build. like heads, block, pistons, head chamber sizes, camshaft "roller cam", rods, crank. ........... you get the idea ......... Yes I think he is nuts and going throw a midlife crisis or something but the ATI procharger and all other parts are laying in my living room and he is obsessed with this 450 inch stroker and yes he can afford it! ....... So help me with parts selection to get this engine underway.

 

How is any of this 3rd gen related?? I will say if he's looking for a large displacement small block (greater than 383) and aluminum he's going to want to look at maybe a LSX type engine. There's a few (maybe 3) companies that offer aftermarket blocks that would support that 454 range.

 

sorry he wants a gen1 smallblock ...... way to much hassle converting the car over to a LSx and all his parts are here and they are for a gen1 block ..... ok make you feel better its a 1990 camaro all this is going into sorry for the typo.
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The block he is looking at is either a motown or dart aluminum. and they both claim they can be built to this displacement.

 

First off, thats a stout build... probly looking at 600-700whp with thsoe cubes and boost, depending on heads/cam/intake


Second, i dont know of any blocks that will give you 450 cubes that are 1 piece rms. You may have to stay with 2 piece.

Bowtie block is 1 piece and capable of giving 434 i believe with its 4.155 bore and a 4 inch crank. If that crank cant be clearanced which it should beable to, you can run a 3.875 crank and make a 420. Id go with that, a 420 is nice

Run big heads like AFR 210's. Stick to a good 210-230cc head. Get pistons for about a 9 to 1 static compression. Safer still wold be 8.5-8.8 to 1.

Your gonna need proper piston compression height and rod length so you can run those large strokes. its gonna be a short piston compression height for sure with a standard 9.025" deck height. Thats why you should get a tall deck 2 piece block (like that dart aluminum) so you can get a proper piston in there with alittle more compression height, or run that bigger 4.200 bore motown block with a 4inch stroke and make 443" but still have a low compression height and the need for custom pistons/rods to make it work on that 9.025" deck height

Custom grind a roller blower cam. With TPi your kinda limiting rpms. Even with the blower it will struggle to feed a LARGE inch motor like that. STill will work tho. Just port the hell out of it, maybe siamese the base alittle.

Run a basic long tube header and that exhaust will work just fine.

Large injectors i'm sure, i'm not sure how big but definately something big enough to feed 700whp. Also need to do the fuel supply end, gotta get a good pump and line to that motor.

that should help for now, just the basics

 

THANKS. He wanted to run his 58cc aluminum heads but told him way to much compression. I believe stock he has 10.25 to 1, Guess he has always wanted a hotrod so he has the money to build it now. I think he is guessing around 8-12K for his engine. Should be one fun car when its done, getting it through smog will be another nightmare.

 

smog i cant help you there...not sure if that motor would pass or not, but i dont see why it wouldnt if you go easy on the cam and use all smog equipment. low compression and little overlap with those cubes will be tame at idle.

by all means, dont skimp out on heads... L98 aluminums leave those to the bolt on guys. Junk them for good heads for that motor. How can you spend 5 grand on a aluminum block and yet use stock heads? Dont do it. This is a serious build your friend is undertaking, do it right

 

what does he have planned intake wise. seems like a waste of money to put such a badazz motor under a TPI

 

nothing about the tpi system is stock and it will be ported out to the limits.

 

would motown 23 degree "world" 02420-2 heads be a good choice for this engine?

 

are those the 220cc intake runner heads? they aint bad but the flow numbers are pretty crappy compared to Darts, Brodix and AFR

 

Stock TPI can be ported, but the runners are still too long. Even if you port them until it's paper thin, the runners are too small.
Look at a mini-ram or equivalent. It's not a high dollar investment.

Orr98 gave a lot of good points up there. I wouldn't get all hung up on hitting 450 cubes. With the blower you can still get really good HP numbers.

I might look at different valve angle heads (lower than 23*). 18 or 15* would really kick up the HP. Unfortunately you need to look at custom pistons for that reason though.

 

mini ram wouldnt be smog legal
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the motown heads have 235cc runners

 

here is what it says about them .............. Solid./Hydraulic Roller 235 cc Runner Manley Stainless Angle 1.437" Dual .600" 64 cc

 

I'm not familar with those heads but they should work ok under the boost. As long as the flow numbers are ok.

Really need to pay attention to your valve train tho. Gotta have the right springs and cam to work with that boost. valvesprings need to be strong to support the pressure of that intake charge. Plus the valves themselves need to be strong good quality stuff.

For that reason i like AFR's packages. Not sure if you and your friend want to keep hydraulic roller or move to the solid, but AFR has valvetrains for both types of cams. Other manufacturers can set you up with a spring package that will work just fine, but dont run solid roller springs on a hydraulic roller else your gonna have some problems. Be aware that most big cc heads are designed with solid roller cams in mind, so they use big springs that have too much pressure

Your gonna really need to sit down and plan this out. Theres alot of things to do for a build of this caliber

 

He wants to stay with hyd. roller cam. ....... Do you know if these mini-rams can be setup to draw EGR gases?

 

Im building something similar except with a superram and less bore and stroke. Thought I show you what pistons I may end up running. I heard these work great for a blown app and have a really good compression ratio. I will end up getting nitrous pins as well for durability. I was recommended these pistons over JE pistons btw. They should be able to hook you up with the bore and stroke you need. May end up costing you less since you need custom pistons.

http://www.cnc-motorsports.com/produ...ID=7189&CtgID=

 

no miniram will not be smog legal. Only options are TPI (i'd look at the big FIRST tpi setup) or Superam if you can find one.

 

So far his intake system is this .... TPIS big mouth intake, SLP 2nd design runners, 58mm TB. He does plan on porting everything out as much as possible. But has considered a mini-ram and just swapping it for smogging when its time. I'm also setting him up with a member from here to datalog and custom burn a chip for the car when it's all done as well as dyno the car. What do you think of fully siamesing the SLP runners? I'm sure it would lose low end but at 12psi I think that would make up for it ........ Does fully siamesing basically shorten runner length and more turn it into larger plenum volume in a sense? With a 450 I would think it would more benefit from fully siamesed runners but keep the base siamesed. He is basically buying a complete TPI parts setup this way all porting can be done with less downtime on the car so right now thats what is in the works is getting this TPI system to flow. I still need to find a plenum though to start opening everything up. I had also pondered with cutting the top off the plenum and smooting it all out and polishing it for smoother airflow then welding it back together. Or is this a waste of time just kind of though if the inside of the plenum were deburred as much as possible then brought to a polished state it would enhance overall airflow.

 

I'd say siamese as much as possible and open up as much as possible a 400+ inch motr will make PLENTY of lowend on its own to move the car, and with TPI/blower, there is gonna be LOADS of low end... probly too much torque and hp at low rpms. its gonna be hard to hook up at all

Clean the plenum up alittle, take out the casting bumps/flaws as best you can. SHould be enough to support that motor with a blower

 

We ran the RPO codes on it and the car had 3.33 gears and a dana44. He is waiting now on 17x11 ZR-1 style rims for it and 315/40zr/17 tires. Definately going to be a interesting car when done. This weekend he wants to order his block and heads. I told him to look into a nice bowtie 4 bolt 1 piece RMS block will save him alot verses and aluminum block and then having to buy a special dual mass flywheel for 2 piece RMS.

 

yeah dont worry about hitting the big cubes. Go with what will work best for that car. Power differences between a blown 450 and a blown 408-427 will be little.
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OR if you want the baddest small block on the planet, one i hope to have someday

http://www.ultrastreet.net/472_classic.asp

472

they use the Dart Tall Deck Iron Eagle Block w/Splayed 4 Bolt Main Caps & Raised Cam

 

Is there an adapter to convert 2 piece RMS to 1 piece RMS ????? I've heard of them but not sure if they only made 1 piece to 2 piece adapters.

 

A question about that engine ... well, a few question .... would his tpis intake bolt to it being that it is a tall deck engine? would his valve covers clear whats under those chrome valve covers? does it have provisions to mount all serpentine drive stuff? and are the head port doable with tpis headers?

 

TPIS intake should bolt to those heads, as i think the TPIS intake is drilled for both style heads, 86 and earlier as well as the 87 and newer. But you'd have to see. those heads are the old style bolt pattern, they are a big 225cc small block head. If you got a 87 up intake you can modify the bolt holes in the center to fit 86 earlier heads.

TPIS base tho probly wont match well to the brodix 225cc intake ports. It shoudl be a 1206 port on the head, while the intake is a 1205 i believe. Not sure how much room you have to port the tpi base to match. Something of concern there. Miniram you can order in a 1206 port

Standard big tube headers will work for those heads. 1 3/4 will cover those exhaust ports fine i believe.

I believe the heads have the standard accessory bracket hole locations and should allow your corvette accessories to bolt up. Else you'll have to run a different setup using different brackets/accessory mounts. Not a big deal i guess but i think your stuff should work

You'll need to run tall valve covers to clear everything more than likely. That base motor is a decent sized solid roller motor, but you can order a hot hydrualic option. If you plan to boost it, you'll need a custom cam anyway.

Then you need lower compression pistons cuz they are rated at 10.5 which is a tad too high for boost But they may beable to build that for you without too much extra cost

 

What do you think of TPIS.com's 414 cu in. small block. It makes 572hp and 517ft lbs tq. He would have a pretty stout engine with the blower wouldn't he? I know it would require lower compression but I would think with his blower this motor could be capable of possibly 700hp. ...... Also I talked to him about a scatter shield but not sure ones made for his car. So I told him maybe a bellhousing scatter shield type blanket since I've heard of them.

 

i havent seen that motor but it does sound pretty good. TPIS has a history of over pricing their products tho.

yes you will easily crest 700hp with a decent blower setup on a large 400+ inch motor.

most D1sc procharged 12-15psi kits on 383's make over 600 at the tires.