Adding 100+ HP to this combo

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plovett
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Re: Adding 100+ HP to this combo

Post by plovett » Sun May 06, 2018 12:41 pm

I'm not an SBC guy, but here goes anyway.

That engine needs 3 things to run right in that car with that gear and convertor.

1) Smaller cam. Say 230 degrees @0.050". LIke a Comp 280 Magnum or similar

2) Better heads. Something like the Dart Iron Eagle 180cc with 49cc chamber, or something similar.

3) Better intake manifold. Eddy RPM Airgap is the obvious answer.

I think those three changes would transform that engine into a street beast. I'd rather see 1-5/8" headers, but I doubt the 1-3/4" tubes are hurting much.

JMO,

paulie

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Re: Adding 100+ HP to this combo

Post by F-BIRD'88 » Mon May 07, 2018 12:55 pm

Rework the distributor so that the mechanical advance curve is locked out.
Ya you read that right. Then set the now locked timing at 34-36deg BTDC.
Assuming and after checking true TDC on the timing marks.
It will not only idle and drive a lot better it will now have the low end responce to melt the
street tires and launch a lot harder. (once on sticky tires) It will be a whole different car.
This car then needs a 4.56 rear gear. ( and NO LESS) A real deal 4000+ stall converter is needed too. Tell your bud to UN fall in love with the 3.42 gears if he ever wants 12's in this car with a 350CID motor. Ya you read that right 4.56 gears
As said the heads are the HP choke. Any of the 2.02 perf heads are a lot better.
I recomend the ATK performance branded Profiler 23deg heads with 195cc intake port.
( these Profiler cast heads have the stock style ex port shape) Add a air gap or a vic JR intake.
With the 4.56's either will work gear.
There are many better cams but this cam is not bad once the heads and gears are right.
( it may run best on say a 104 -105 ish in C/L once the heads and gears are right.)

Lock out that distributor curve and you will start the path to what he wants.
( Install a ignition interupt switch to allow hot motor restart with the locked timing.)
This cam needs that. Once locked out use ported vacuum advance too.
(34-36deg locked out timing and +10-12deg of ported vacuum advance)
This mod is easy to do on a GM HEI distributor.

use champion RV8C plugs .035" gaps or cross reference eg AC delco R42T
in the stock #601 heads. These heads get a lot better with aggressive porting and larger 1.94-1.60 valves. But the ATK version profilers are what you want.

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Re: Adding 100+ HP to this combo

Post by F-BIRD'88 » Mon May 07, 2018 1:31 pm

As suggested another good path to 12's in this street 3800 lbs camaro with the 3.42 gears is to supercharge it. Swap the heads for a 76cc+ chamber SBC head with home porting and bigger valves
( eg 441 336 920 etc chev 76 cc heads) to drop the compression ratio.
Weiand 177 blower Edelbrock/Magnuson Eaton MP122HH "E Force blower"

TorQStorm (blow thru) Supercharger... Ya it will cost a bit more than $1500 but you will get the 12sec perf you want (and beyond)

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Re: Adding 100+ HP to this combo

Post by F-BIRD'88 » Mon May 07, 2018 1:42 pm

And yes I can also show you how to transform this 3800 lb car with 350 into a very strong running 12sec performer using a Tunnel RAM. U can even get there using that 246 246 .509 .509 cam. (although I have much better cams to suggest for this) But again get your head around 4.56 gears.. 5.13:1 is the highest ratio for that 10 bolt rear and even that gears is not too much for this #3800 car.

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Re: Adding 100+ HP to this combo

Post by GARY C » Mon May 07, 2018 1:52 pm

This car then needs a 4.56 rear gear. ( and NO LESS) A real deal 4000+ stall converter is needed too.
Interesting... I did it with a 2800/3200 converter, 3.73 gear and a 26" used slick in this car with the 50 series front tires, big front sway bar and KYB gas shocks.
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Re: Adding 100+ HP to this combo

Post by Monza355 » Mon May 07, 2018 4:15 pm

GARY C wrote:
Mon May 07, 2018 1:52 pm
This car then needs a 4.56 rear gear. ( and NO LESS) A real deal 4000+ stall converter is needed too.
Interesting... I did it with a 2800/3200 converter, 3.73 gear and a 26" used slick in this car with the 50 series front tires, big front sway bar and KYB gas shocks.
What camshaft did you run Gary ?

You must be doing something wrong if you need 4.56 gears and a 4000+ stall converter to run in the 12 second zone :lol:

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Re: Adding 100+ HP to this combo

Post by GARY C » Mon May 07, 2018 5:17 pm

Monza355 wrote:
Mon May 07, 2018 4:15 pm
GARY C wrote:
Mon May 07, 2018 1:52 pm
This car then needs a 4.56 rear gear. ( and NO LESS) A real deal 4000+ stall converter is needed too.
Interesting... I did it with a 2800/3200 converter, 3.73 gear and a 26" used slick in this car with the 50 series front tires, big front sway bar and KYB gas shocks.
What camshaft did you run Gary ?

You must be doing something wrong if you need 4.56 gears and a 4000+ stall converter to run in the 12 second zone :lol:
It was one of Comps first street rollers, I think they called it a 255/525 or 575.
It was around a 10:5.1 compression ported DBL hump head and I think 1.6 rocker but thats been over 20 years ago.

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Re: Adding 100+ HP to this combo

Post by John Wallace » Mon May 07, 2018 6:38 pm

Interesting... I did it with a 2800/3200 converter, 3.73 gear and a 26" used slick in this car with the 50 series front tires, big front sway bar and KYB gas shocks.
SBC also?

:?:

Pontiac Power Rules!!!

:mrgreen:
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Re: Adding 100+ HP to this combo

Post by GARY C » Mon May 07, 2018 7:02 pm

John Wallace wrote:
Mon May 07, 2018 6:38 pm
Interesting... I did it with a 2800/3200 converter, 3.73 gear and a 26" used slick in this car with the 50 series front tires, big front sway bar and KYB gas shocks.
SBC also?

:?:

Pontiac Power Rules!!!

:mrgreen:
Yes, 355 Cheby.
Here is the Pontiac 400 4spd T/A I almost finished a cpl years ago.
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Re: Adding 100+ HP to this combo

Post by midnightbluS10 » Mon May 07, 2018 8:17 pm

Nice! We had a white SD 455 come in the shop a couple of years ago for a new starter. I enjoyed every minute of that. :mrgreen: First time I had seen one up close.

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Re: Adding 100+ HP to this combo

Post by GARY C » Mon May 07, 2018 11:55 pm

midnightbluS10 wrote:
Mon May 07, 2018 8:17 pm
Nice! We had a white SD 455 come in the shop a couple of years ago for a new starter. I enjoyed every minute of that. :mrgreen: First time I had seen one up close.
That was my dream car from child hood but as I got older I couldn't justify the cost, I built the 400 4speed car because I could do it with the few upgrades I wanted and keep it at or below $10,000.00

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Re: Adding 100+ HP to this combo

Post by travis » Tue May 08, 2018 2:05 am

Now that this guy knows where I live :x he came by late Sunday and apologized profusely. Said he had been yanked around by several engine builders, and was just bleeding money on this project, thus the frustration on his part. We talked for a couple of hours...I gave him my opinions on achieving what he wanted, he agreed that the cam was too big and was willing to lose some of the sound if the thing would actually run. I haven’t agreed to work on it yet...still undecided but I could use the money to help get my shop built. First impression left me thinking I don’t want any part of this...

Here’s what I’m thinking, based on the scribbled notes from whoever built the engine. Trick Flow DHC 175cc aluminum heads w/60cc chambers and .022” gaskets will get it up to just a hair under 10:1. RPM air gap, and a Lunati 268 Voodoo cam. Should make a lot more power everywhere, power brakes will work properly, still have some sound, and should get him to his goals or very close. I recently built a very similar 351w (9.9-1, 180 iron eagles, 268 voodoo, weiand stealth, etc) that is in an ‘80’s fox body with 3.55’s and a 5 speed running 12.50’s, so even though this Camaro is 600 pounds heavier it should work. Thoughts?

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Re: Adding 100+ HP to this combo

Post by GARY C » Tue May 08, 2018 3:26 am

travis wrote:
Tue May 08, 2018 2:05 am
Now that this guy knows where I live :x he came by late Sunday and apologized profusely. Said he had been yanked around by several engine builders, and was just bleeding money on this project, thus the frustration on his part. We talked for a couple of hours...I gave him my opinions on achieving what he wanted, he agreed that the cam was too big and was willing to lose some of the sound if the thing would actually run. I haven’t agreed to work on it yet...still undecided but I could use the money to help get my shop built. First impression left me thinking I don’t want any part of this...

Here’s what I’m thinking, based on the scribbled notes from whoever built the engine. Trick Flow DHC 175cc aluminum heads w/60cc chambers and .022” gaskets will get it up to just a hair under 10:1. RPM air gap, and a Lunati 268 Voodoo cam. Should make a lot more power everywhere, power brakes will work properly, still have some sound, and should get him to his goals or very close. I recently built a very similar 351w (9.9-1, 180 iron eagles, 268 voodoo, weiand stealth, etc) that is in an ‘80’s fox body with 3.55’s and a 5 speed running 12.50’s, so even though this Camaro is 600 pounds heavier it should work. Thoughts?
It looks like you have a good plan, he will actually be surprised with how it sounds and runs, I wish I could post my Pontiac 9.1 compression with a comp 268 but the site does not accept the platform.

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Re: Adding 100+ HP to this combo

Post by travis » Tue May 08, 2018 4:04 am

I think it will still sound great...I know that 351w does.

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Re: Adding 100+ HP to this combo

Post by Carnut1 » Tue May 08, 2018 6:11 am

Has it ever been discussed the difference in sound between ported heads and unported? I thought that an improved exhaust port will go sonic and stay sonic longer. Giving it a snap. This may be way out in left field but it was the early 90's. Thanks, Charlie
Servedio Cylinder Head Development
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