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 1320 (Pontiac Straightline Performance)
 Going Solid Roller...What should I expect to pick
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gjn
Running Brave

USA
63 Posts

Posted - 03 Apr 2009 :  12:09:52 PM  Show Profile  Reply with Quote
Well, I am going solid roller. My hydraulic cam was starting to pit and I decided to go ahead and go roller. I ordered the cam this week from Butler. The solid roller cam lobes are from the Comp XE line and the specs are 254/260 .621/.627 with 1.6 rockers on 112. My current cam was a Striaghtline Performance cam with these specs - 236/250 with .544/.544 on 112. With the Hydraulic Cam I ran a best 11.637 @115.45 with a 1.657 60" in great air. I typically ran high 11.6's to high 11.7's at 114 to 115 in typical air here in KC. I am also upgrading my exhaust from the comp 1 5/8" headers and 2 1/2" Flowmaster exhaust with H-Pipe to supercomp 1 3/4" headers and 3" x-pipe with 3" ultraflows. In addition, I am converting to manual brakes/steering. What do you think I will pick up in ET/MPH?

My set up before these upgrades listed above.

68 Firebird 400
Race Weight 3,580

Suspension:
Front:
90/10 Koni's
Stock Springs
Sway Bar removed
Rear:
Rancho Shocks
Cal Tracs
Cal Trac Split Mono Leaf Springs
MT Drag Radials - 275/50 - 19 lbs.
Motor:
461
#16 - Flow 250 cfm @ .5
Straight Line Performance Cam 236/250 .544/.544 on 112
Scorpion 1.6 Roller Rockers
Zero Decked
9.45 compression
800 Pro Systems double pumper
8 Gallon Fuel Cell
Holley Blue Fuel pump with Moroso Spring and h 1/2" lines
RPM Intake with Divider Cut
30 degrees advance all in by 1,800 RPMs
1" 5/8 inch headers
2 1/2" flowmaster exhaust with h-pipe
400 Turbo
10" Continental - 3.2k stall
3.25 Ford 9"

1968 Firebird
461
3.25
11.637 @ 115.45

Bill Boyle
Horse Feathers (Charter Member)

USA
4793 Posts

Posted - 03 Apr 2009 :  2:47:58 PM  Show Profile  Visit Bill Boyle's Homepage  Reply with Quote
Hi Greg,
That's a significant jump in duration and lift over your current cam set up. With your 16 heads ported to allow 250 at .5 lift, you may not have enough intake flow currently to take advantage of the increase duration and lift. You may run a faster mph but ET may be off. That's my guess.

Clearly one of the choke points with your current engine was the small tube header size. Exhaust proficiency was holding you back. Upgrading your exhaust would have provided a quicker et and mpg gain at the track with your current set up. It won't hurt the new set up!

With a new, larger, high lift solid roller in play, I believe you're ready for a Torker II intake matched to ported E-heads or KRE aluminum heads. [Probably not what you wanted to read.]

Bill

"Dedicated to keeping the classic Pontiac engine alive."

----
400 bored +.030, forged TRW pistons, ported 62 heads, Hedman headers, 2.5 SS dual exhaust X Pypes, Comp 276AH10 cam, Scorpion 1.65 RR, 850 Q-jet, stock intake & tuned HEI; original owner.
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gjn
Running Brave

USA
63 Posts

Posted - 04 Apr 2009 :  6:29:30 PM  Show Profile  Reply with Quote
quote:
Originally posted by Bill Boyle

Hi Greg,
That's a significant jump in duration and lift over your current cam set up. With your 16 heads ported to allow 250 at .5 lift, you may not have enough intake flow currently to take advantage of the increase duration and lift. You may run a faster mph but ET may be off. That's my guess.

Clearly one of the choke points with your current engine was the small tube header size. Exhaust proficiency was holding you back. Upgrading your exhaust would have provided a quicker et and mpg gain at the track with your current set up. It won't hurt the new set up!

With a new, larger, high lift solid roller in play, I believe you're ready for a Torker II intake matched to ported E-heads or KRE aluminum heads. [Probably not what you wanted to read.]

Bill




Jim Bulter thought this cam would maximize my heads. They flow 252 at .6". I don't think I will lose any 60' and actually hope to pick up some. Only time will tell. It should be mid summer before, I get back to the track. I also asked him about the intake and he felt the RPM would be the best. I am looking forward to see what it will run.

1968 Firebird
461
3.25
11.637 @ 115.45
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Bill Boyle
Horse Feathers (Charter Member)

USA
4793 Posts

Posted - 04 Apr 2009 :  7:14:36 PM  Show Profile  Visit Bill Boyle's Homepage  Reply with Quote
Greg,the big cam may max out you 16 heads and leave plenty of untapped potential for more flow found with ported aluminum heads. Jim Butler probably knows what he's talking about with the cam selection and head combination. Once you have it all put together, let us know how the Bird performs at the strip. I'd love to update your engine combination and progress in the Torque Power section.

Bill

"Dedicated to keeping the classic Pontiac engine alive."

----
400 bored +.030, forged TRW pistons, ported 62 heads, Hedman headers, 2.5 SS dual exhaust X Pypes, Comp 276AH10 cam, Scorpion 1.65 RR, 850 Q-jet, stock intake & tuned HEI; original owner.
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Mr. P-Body
Running Bear

USA
2258 Posts

Posted - 07 Apr 2009 :  08:56:11 AM  Show Profile  Visit Mr. P-Body's Homepage  Reply with Quote
Greg,

If you haven't already taken delivery of the cam (or ordered it), call them and change the LSA BACK to 110. XE grinds ALWAYS work better there. Cam "convention" does not apply to these grinds. The only complaints we hear about the XE series as far as power production is concerned, is when the LSA is moved away from their 110 recommendation.

FWIW

JIm


Edited by - Mr. P-Body on 07 Apr 2009 08:56:36 AM
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Lee
Sitting Bull

101 Posts

Posted - 18 Jan 2010 :  8:35:04 PM  Show Profile  Visit Lee's Homepage  Reply with Quote
gin,

Jim and I often have differing opinions, but I'd also suggest you go narrower on the LSA.

My old bird was pretty similar to yours - parts and performance. I had a smaller cam (231/239 108LSA UltraDyne), a bit more CR and gear (3.42), but taller 275/60 MT DR's. I used a T-II and a 750DP. I had gotten into the 11.5's 115's, before I swapped cams.

I went a bit milder, using a 247/247 solid flat tappet on a 108 LSA (also an UltraDyne grind). I also had the heads freshened and much stiffer springs installed. with no other changes, my performance improved into the 11.3's 118's, but I DID lose 60' (about .06 on average). Not relevant, but after changing mufflers I picked up an additional .9/1.1 in performance.

IMHO, I would have gone a bit smaller on your duration, considering your compression ratio, and stall speed. I think you'll need to increase your stall speed at least 500rpm to retain your 60' times. I'd knock 4 to 6 degrees duration off, and tighten the LSA at least to 110 (and probably 108).

Good luck!
Lee Atkinson

CURRENT: '73 T/A clone, boring at the moment...
67 Firebird (sold) 11.27 @ 119.6 Feb. '05 issue HPP
69 Falcon wagon, 10.51 @ 130mph Feb. '10 issue PHR (sold)
72 Cutlass Convertible, first car, owned since '82, now with a 6.0 LS, mild, putting just under 400 hp/tq to the wheels.
www.LNLPD.com
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Jeff Fritchie
Sitting Bull

136 Posts

Posted - 24 May 2010 :  7:05:11 PM  Show Profile  Reply with Quote
GJN have any updates on your combo? Is it back in one piece yet? what did you go with on the cam?
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Christ
Howling Wind

USA
1808 Posts

Posted - 24 May 2010 :  10:38:19 PM  Show Profile  Visit Christ's Homepage  Reply with Quote
I had a very simliar cam almost the same spec's. The 112 seems to work better with out nitrous and a lower gear. I go with the 110 if he had a stepper gear of 3:90. Either way it be a great cam choice!
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Bill Boyle
Horse Feathers (Charter Member)

USA
4793 Posts

Posted - 25 May 2010 :  07:41:50 AM  Show Profile  Visit Bill Boyle's Homepage  Reply with Quote
Guys, Greg is trying to sell the car.

http://psp.aquacomp.net/topic.asp?TOPIC_ID=3851

"Dedicated to keeping the classic Pontiac engine alive."

----
400 bored +.030, forged TRW pistons, ported 62 heads, Hedman headers, 2.5 SS dual exhaust X Pypes, Comp 276AH10 cam, Scorpion 1.65 RR, 850 Q-jet, stock intake & tuned HEI; original owner.

Edited by - Bill Boyle on 25 May 2010 07:43:41 AM
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Jeff Fritchie
Sitting Bull

136 Posts

Posted - 25 May 2010 :  7:28:03 PM  Show Profile  Reply with Quote
man that sucks!!!!!! sorry to here that greg. Well I'm going to be selfish and hope it does not sell. hope all works out well for you and things come back around and slow down for you to enjoy the car again. some day
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Total Jackass
Tribal Scout

0 Posts

Posted - 14 Jan 2014 :  04:44:31 AM  Show Profile  Reply with Quote
A. A shooting star!
http://www.coswatches.net/rolex-sea-dweller.html

I'm a first class jerk and don't you forget it!
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Phil
The Great White Buffalo

USA
7214 Posts

Posted - 14 Jan 2014 :  6:38:57 PM  Show Profile  Reply with Quote
TTT

Bowties are for Pee-wee Herman. "Chevy": even the name sounds cheap, but not as cheap as your Pontiac will be with an LS transplant.
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