[Stan Weiss]

The dyno sheets could have shown some more data. Hard to tell what is going when there are some numbers not just could not be correct. Look at the marked BSFC numbers.

Stan

[mgarblik]

Those BSFC numbers do happen from time to time on Superflow SF901 dyno's . We have seen them as well unfortunately. They are derived from electro-mechanical devices. The "air hat" has an impeller that can be interrupted or effected by the quality of the air entering it and the way it is joined to outside air system in the cell. The fuel meter is an impeller style flow meter, which is effected by the quality of the regulator, the amount of fuel in the fuel cell and any air that may get into the system. Of course this screws up analysis of the data as you stated. Superflow says to always ignore the first 200 RPM's of data at the beginning of the pull and the last 200 RPM's as well. I would guess they would say to also ignore weird readings like you found as well. We always make multiple pulls to average the meaningful data. Good catch! No way that block of data means anything.

[Pontiac Derek]

He used a Butler 230-236 cam on a 112lsa, aka xe274 marine hydraulic cam
not what I would ever recommend especially using XE lobes that small at 9.7:1 he’s lucky in Canada they are using 94 octane!
2nd he was way lean, every time I’ve made best power with a Q-jet it’s been between 11.8-12 AFR not 13 and that’s probably partially to do with the secondary air flap not being modified to open fully, stock they are way off.
I’ve run back to back test between A-body 2.5” rare manifolds and hooker sc 2.00 headers on a 568hp 470 and the manifolds were down 30hp at that power lever, I have not tested them on a D port setup but at 400hp area I doubt there is much to be gained in hp but you definitely will gain some torque imho
Nick seems like a good guy, just not a Pontiac specialist

[Jay S]

Bulter’s are Pontiac specialist though, the new cam was Butler’s. They pretty frequently recommend that particular cam, likely was their recommendation, not Nick’s.

[Stan Weiss]

I have not used either of these cams. So all I can do is look at numbers on a piece of paper. So I am wrong to think that the Comp Cams XE274 is pretty close to a Lunati 703?

Stan

[Pontiac Derek]

Originally Posted by Stan Weiss

I have not used either of these cams. So all I can do is look at numbers on a piece of paper. So I am wrong to think that the Comp Cams XE274 is pretty close to a Lunati 703?

Stan

They used the 702 lunati cam then went to the wider lsa 274 xe comp cam
The 702 cam is 219-227 at .050, the 703 is 227-233 at .050 so a little smaller

[PDC]

Several years ago when I went through my 455 with the new 1-piece rear main seal, new BOP factory style oil pan and 1-piece Viton pan gasket, I decided to do a cam swap since the engine was out of the car anyway. I spoke with Butler and they suggested the 274 on a 112* LSA. I went that route and had the cam Nitrided for peace of mind an ordered a set of legit Made in USA Hylift Johnson lifters from them. Mission creep resulted in a set of out of the box Edelbrock 87cc D-ports (Butler was backlogged 6 weeks on head porting and my car was already at the shop.)

Message to OP - that car literally never dripped another drop of oil. Period.

Yes, I know there are better cams that will make more power - all other factors being the same. But I went from an XE-268 with un-ported 6X heads to the XE-274 on a 112* LSA with 87cc Edelbrock D-Ports and could not have been happier with the results. It felt like an entirely different car. It was a 4-speed car with am M22-Z gearset feeding a 3.08 rear end. For a fair weather, local cruise car, I was plenty happy.

FWIW - Hot Rod Magazine got near the exact same 390 hp and 490 tq as Nick did on this build way back in the day when they swapped 96cc 7k heads onto their junkyard 455 with the XE-274 cam. That same boneyard build made 440 hp and 550 tq on bathtub chamber 1st gen 87cc Round Port E-Heads.

[Pontiac Derek]

Your saving grace is having a good flowing set of E-heads on there, what rpm was peak hp?

Originally Posted by PDC

Several years ago when I went through my 455 with the new 1-piece rear main seal, new BOP factory style oil pan and 1-piece Viton pan gasket, I decided to do a cam swap since the engine was out of the car anyway. I spoke with Butler and they suggested the 274 on a 112* LSA. I went that route and had the cam Nitrided for peace of mind an ordered a set of legit Made in USA Hylift Johnson lifters from them. Mission creep resulted in a set of out of the box Edelbrock 87cc D-ports (Butler was backlogged 6 weeks on head porting and my car was already at the shop.)

Message to OP - that car literally never dripped another drop of oil. Period.

Yes, I know there are better cams that will make more power - all other factors being the same. But I went from an XE-268 with un-ported 6X heads to the XE-274 on a 112* LSA with 87cc Edelbrock D-Ports and could not have been happier with the results. It felt like an entirely different car. It was a 4-speed car with am M22-Z gearset feeding a 3.08 rear end. For a fair weather, local cruise car, I was plenty happy.

FWIW - Hot Rod Magazine got near the exact same 390 hp and 490 tq as Nick did on this build way back in the day when they swapped 96cc 7k heads onto their junkyard 455 with the XE-274 cam. That same boneyard build made 440 hp and 550 tq on bathtub chamber 1st gen 87cc Round Port E-Heads.

[PDC]

Originally Posted by Pontiac Derek

Your saving grace is having a good flowing set of E-heads on there, what rpm was peak hp?

I’m sure it was low - 4700/4800??

My ‘other’ car was a ‘73 400 block, .030 over with a Butler prepped Eagle 4.25 rotating assembly and Ross Flat-Tops .005 in the hole. That one had Butler Prepped 87cc D-Ports which flowed 290 intake and 210 exhaust. The cam in that one was spec’d by Charlie Kabbaby of Warpath Performance. It used the exhaust lobe of the XE274 as an intake lobe, and the intake lobe of the XE284 as the exhaust lobe on a 112* - so it was 236/240 @ .050 and .290/.284 @ .006 with .490/.507 lift. That engine was an MF’r. With that cam and ported aluminum heads with 3” mains, it would rev up like a small block and made 500 hp and 550 tq all day any day. I had a TKO-600 in that car spinning 3.23s out back. That car was nails anywhere on the tach in any gear. Hope the new owner is enjoying her!!!

[Pontiac Derek]

Originally Posted by PDC

I’m sure it was low - 4700/4800??

My ‘other’ car was a ‘73 400 block, .030 over with a Butler prepped Eagle 4.25 rotating assembly and Ross Flat-Tops .005 in the hole. That one had Butler Prepped 87cc D-Ports which flowed 290 intake and 210 exhaust. The cam in that one was spec’d by Charlie Kabbaby of Warpath Performance. It used the exhaust lobe of the XE274 as an intake lobe, and the intake lobe of the XE284 as the exhaust lobe on a 112* - so it was 236/240 @ .050 and .290/.284 @ .006 with .490/.507 lift. That engine was an MF’r. With that cam and ported aluminum heads with 3” mains, it would rev up like a small block and made 500 hp and 550 tq all day any day. I had a TKO-600 in that car spinning 3.23s out back. That car was nails anywhere on the tach in any gear. Hope the new owner is enjoying her!!!

Cool, and again with a larger intake port E-head they work better than with a 165cc iron head,
Regardless it is just the way I do things, I’ve learned that short seat timing camshafts just don’t do as well on Pontiacs in my personal experience
Now with Dave’s old faithful Version 1 which was 236-244 at .050 112lsa installed at 110ilc 290-306 advertised iirc
My ported 320cfm e heads, 470cid 10.25:1 ported RPM intake made 568hp from 5500-5800 rpm and 589tq from 43-4700rpm now it was a hydraulic roller so not apples to apples but still

[PDC]

Originally Posted by Pontiac Derek

Cool, and again with a larger intake port E-head they work better than with a 165cc iron head,
Regardless it is just the way I do things, I’ve learned that short seat timing camshafts just don’t do as well on Pontiacs in my personal experience
Now with Dave’s old faithful Version 1 which was 236-244 at .050 112lsa installed at 110ilc 290-306 advertised iirc
My ported 320cfm e heads, 470cid 10.25:1 ported RPM intake made 568hp from 5500-5800 rpm and 589tq from 43-4700rpm now it was a hydraulic roller so not apples to apples but still

Absolute ‘glass ceiling’ where a FT cam just cannot produce the numbers that a Roller will produce. I loved every mile and every smile behind the wheel of both of my ‘traditional’ Poncho powered TAs. I have since sold both of them and used the proceed to get into my ‘current’ car which is another ‘73 running (GASP!) an LS9 with a Lingenfelter 710 kit twisting a T-56 Magnum into a 3.73 Ford 9” rear. DSE Front and Rear suspension, Rear Q-Link, mini-tubbed. It’s just unreal. But it has sadly pissed off 2 or 3 tru believers here…

[grandam1979]

Originally Posted by PDC

Absolute ‘glass ceiling’ where a FT cam just cannot produce the numbers that a Roller will produce. I loved every mile and every smile behind the wheel of both of my ‘traditional’ Poncho powered TAs. I have since sold both of them and used the proceed to get into my ‘current’ car which is another ‘73 running (GASP!) an LS9 with a Lingenfelter 710 kit twisting a T-56 Magnum into a 3.73 Ford 9” rear. DSE Front and Rear suspension, Rear Q-Link, mini-tubbed. It’s just unreal. But it has sadly pissed off 2 or 3 tru believers here…

Do you have any pictures of the car? Thanks

[PDC]

Originally Posted by grandam1979

Do you have any pictures of the car? Thanks

You bet - she’s in the ‘Non-Pontiac Motors in Pontiac Cars’ sub forum:

https://forums.maxperformanceinc.com...d.php?t=854111

And:

https://forums.maxperformanceinc.com...d.php?t=855445