A friend of mine wants to put a Super Charger on his 434 Small Block.

He's had a lot of work done to a set of AllPro heads and the engine was being built initially to be N/A.

Now in mid-stream he wants to use a super charger too.

Any comments would be appreciated.

Jake

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1986 Corvette Coupe, 415 CID, Edelbrock 6073s, ZZ9

 

Until recently, I was running a 383" with a Vortech S-trim pullied for 15 psi. Ain't no thing. What do you need to know?

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1989 T/A, 400" CNC Bow-Tie tall-deck, JE 8.5:1, Eagle 6" rods, Crower roller cam, AFR heads, Accel Pro-Ram intake, 1200-cfm t/b, DFI, 72# inj., S/X fuel system, HRC T76 turbosystem, NOS 150-hp dry fogger, TH400 w/GV overdrive, 12-bolt w/3.70's, Baer Track brakes, 18X9.5 wheels, P275/35ZR18 Nittos, Spohn suspension, S/T springs, KYB AGX shocks/struts, Corbeau Targa RS seats, TeamTech 5-point harnesses, Sparco steering wheel, MacEwen white gauge overlays, Phantom gauges/tach, B&M Pro Stick w/carbon-fiber ****, REAL carbon-fiber dash/console kit (don't ask), S&W 8-point rollbar, Lonza aluminum pedal covers, Pioneer/Boston Acoustics stereo system, filled side markers, Audi clear fender marker lights, custom clear front turn signals, custom clear taillights, IMSA-style cowl hood (don't ask), custom medium Intense Blue pearl paint, tinted glass. Whew!

Best ET w/383" S-trim: 10.796 @ 125.8 mph
Best ET w/400" turbo, nitrous: Summer 2001

Member of Midwest F-Body Association www.mfba.org

 

Okay, here goes.

He's had the heads worked toward the goal of 340 CFM @ 28" water and has had his Miniram worked to matchthe raised ports of the AllPro heads.

The intake port volume of the heads hasn't been finalized yet, but they should end up in the 260/270 cc range.

I recently returned the custom pistons he'd bought from HTC which have a 10cc dish. They are going to be exchanged or reworked to increase the dish so as to lower the compression. We'd like to get the CR down to 10.0:1, which would call from about 15 more ccs out of the piston for a total of 25 ccs. That, according to my calculations, will give 10.2. A 20cc increase in dish (giving a total of 30 ccs) would put it at 9.75.

All the internals are the best forged, four bolt stuff you can buy.

Is there a S/C that can work effectively with heads and CID this big? I'm concerned that boost will build too slowly because of size of the ports, etc.

I read that the Miniram causes distribution problems when using a S/C; any thoughts on this?

Any experiences you have had or other info would be appreciated too.

BTW, the engine will be going in an 86 Vette with a competition rebuilt 700R4 and Gear Vendor.

Thanks,

Jake

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1986 Corvette Coupe, 415 CID, Edelbrock 6073s, ZZ9

 

I am interested in what you said about having the miniram worked on to accept the bigger heads. Was it a mini that was originally made for stock type ports? And what did you do to make it work with bigger ports. My mini is on afr 190's and I would like to get 210's but dont want to buy another mini. If you are good with fabrication,the rear of the miniram could be made larger to make more plenum volume. This would probably cure distribution problems. I could easily see putting another 1.5 to 2" box on the back of the intake with a small cap hei. I would hate to have to work with a superram and think this would be a good solution. Now that ive talked about it I think Im going to draw something up on cad. Im sure tpis would have done this if they didnt have to worry about people with big hei cars.

 

The Minram is the TPIS manifold which was originally bought for AFR 210s which had regular height ports.

The AllPro heads are raised port versions and there was a tremendous mismatch. So the Miniram had it's ports raised to match the AllPros by welding aluminum to each port, then porting and contouring the ports.

There isn't enough meat at the top of the MiniRam ports to be able to open them to the size and location of the raised AllPro ports, so aluminum had to be added to give 'porting/matching' material to work with.

Hope this helps.

Jake

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1986 Corvette Coupe, 415 CID, Edelbrock 6073s, ZZ9

 

well, tory hess was using a T-trim vortech on his 406 and was running 10 flat at 16psi and that was with 210cc heads.

 

I've got a buddy doing the same thing to his 434. He has been running naturaly asperated (+ nitrous) for the last couple of years. He decided this winter to go blown. He bought a Procharger D2r + intercooler. He's changing pistons, the camshaft & intake manifold. He has well worked over Brodix heads (X11 if I remember correctly.) He's going to use a Holley tunnel ram.

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Tracy /AKA IROCKZ4me
'86 IROC-Z Camaro
"Cogito ergo zoom"

• 355 cid
• AFR heads
• Arizona Speed & Marine hydraulic roller cam w/ AFR hydra-rev kit
• modified SLP runners
• TRW forged pistons/ceramic coated
• fully balanced
• Edelbrock headers/ceramic coated
• SLP cat-back
• Paxton supercharger
• Nitrous Express nitrous oxide

My IROC-Z
EFI Performance Club on Yahoo
Club IROC-Z

 

Thanks, is his car up and running S/C yet?

If he's on-line I'd like to find out how big he went with his camshaft selection, etc.

I'm concerned that the camshaft Steve had custom ground by CompCams may have too much duration.

Jake


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1986 Corvette Coupe, 415 CID, Edelbrock 6073s, ZZ9

 

i'm better is looks like a lot but you have to remeber the cam needs enough duration to help allow the the heads to fill and he has HUGE intake ports if i remember right, you said like 230cc right? well the cam is going to need a lot of duration to help fill those big intake ports....look at it that way.

 

They're even bigger than that: they are approaching oval port Big Block size, somewhere around 260/270 ccs.

He ordered a cam with 244/256 @ .050, mechanical roller from CompCams. It's ground on 108.

Jake


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1986 Corvette Coupe, 415 CID, Edelbrock 6073s, ZZ9

 

well, the duration seems to be ok to me. i'm been learning about cams and if he spins that motor to about 7000rpm that cam should be fine. but that lope separation has to go. 108* isn't any good for a blower/turbo cam. you want something between 112-114

 

Not yet. He is in mid transformation now.
89ProchargedROC is correct. He will need to run good duration numbers to feed that much CID and use all that port volume to it's full potential. You do want to run wider lobe seperation angles with forced induction to minimize overlap.
I'll be talking to my buddy this weekend. I'll see excactly what cam specs he'll be running.

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Tracy /AKA IROCKZ4me
'86 IROC-Z Camaro
"Cogito ergo zoom"

• 355 cid
• AFR heads
• Arizona Speed & Marine hydraulic roller cam w/ AFR hydra-rev kit
• modified SLP runners
• TRW forged pistons/ceramic coated
• fully balanced
• Edelbrock headers/ceramic coated
• SLP cat-back
• Paxton supercharger
• Nitrous Express nitrous oxide

My IROC-Z
EFI Performance Club on Yahoo
Club IROC-Z

 

I suspected as much. See, changing horses in mid-stream is never a good idea. The cam selection was made based on the engine being N/A.

Now that he wants to S/C it, the pistons would provide too much compression, so they've got to be swapped and now you are saying the Lobe Separation Angle is too tight.

If I had known he planned to make a swap to a S/C I'd have done more research sooner to enable us to get the correct cam for the combination.

It's a BIG mistake to start off with a mis-matched combination and then try to tune it later to perform up to expections.

You can't make a silk purse out of a sow's ear.

Thanks for the input.

I'll post any developments as they happen.

Jake


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1986 Corvette Coupe, 415 CID, Edelbrock 6073s, ZZ9

 

glad to help

 

Hey jakejr,
his old cam was:
<table border="1"><tr><td> </td><td>Valve lift</td><td>duration @ .050"</td><td>LSA</td></tr><tr><td>Intake</td><td>.700"</td><td>275°</td><td>106°</td></tr><tr><td>Exhaust</td><td>.700"</td><td>285°</td><td> </td></tr</table>


His new cam is:
<table border="1"><tr><td> </td><td>Valve lift</td><td>duration @ .050"</td><td>LSA</td></tr><tr><td>Intake</td><td>.715"</td><td>255°</td><td>112°</td></tr><tr><td>Exhaust</td><td>.715"</td><td>255°</td><td> </td></tr</table>

His heads flow:
325 CFM @ .700" lift intake.
250 CFM @ .700" lift exhaust.
Intake port volume = 235 CC.

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Tracy /AKA IROCKZ4me
'86 IROC-Z Camaro
"Cogito ergo zoom"

• 355 cid
• AFR heads
• Arizona Speed & Marine hydraulic roller cam w/ AFR hydra-rev kit
• modified SLP runners
• TRW forged pistons/ceramic coated
• fully balanced
• Edelbrock headers/ceramic coated
• SLP cat-back
• Paxton supercharger
• Nitrous Express nitrous oxide

My IROC-Z
EFI Performance Club on Yahoo
Club IROC-Z

 

Okay. The cam was changed from the original 108 lobe seperation angle one and it arrived today.

It's a custom grind from CompCams; a mechanical roller: @ .050 244/256 on 111 LSA. It uses their RT series intake lobe.

Now we're waitng to hear from Hank The Crank in CA on just what he'll be able to do with the pistons to lower the CR.

I did the match and we'd need a dish of at least 25 cc to get the CR down to 10.25:1. The heads have combustion chambers of 58 ccs, but they'll be opened to 60.

The heads and MiniRam are being flowed together now. Should have some bottom line flow numbers on a couple of days. The heads flow 340 cfm @ 28", but with the miniram bolted on it drops the flow to 320.

We've had the MiniRam cut open to allow some interior porting so try to eliminate the turbulance that develops at higher valve lifts. Bob's going to try a slightly smaller valve to see if that will improve the flow.

We're shooting for 340 cfm with the intake bolted to the head.

I'll keep you posted.

Jake



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1986 Corvette Coupe, 415 CID, Edelbrock 6073s, ZZ9