[steve25]

That’s true and a point that I missed!
The Pontiac is also wider up top then the SBC, so overall the intake runners are longer helping out torque production also!

[pastry_chef]

Originally Posted by 72LuxuryLeMansLa.

I have a Summit 2800 flat tappet that Jim Hand told me was perfect for a low compression stock 350.

Summit 2800.
Advertised Duration: 278 int./288 exh.

It would interesting what tappet rise that advertised rating is at?

In a low compression engine I'm VERY concerned about when the valve actually opens and seats. Delaying intake valve close there is very bad!
Opening the exhaust valve earlier at low RPM hurts torque, as does closing the exhaust valve later.

The Comp HE268 lobe has 272.8 duration @ .0045 tappet rise.
but 218.6 @ .050 for breathing.

https://www.youtube.com/watch?v=m9dSIUFWNpg
14 flat is decent for a low compression stock head 350 Pontiac.. granted it has some good gears.
Running very close to the valve events Dynomation 6 said was the best from 2000 to 4500 RPM, in truth the program wanted 107 LSA but modelling was with headers.
I kept intake valve close and exhaust valve open the same, I presume the OP here is running exhaust manifolds.

[Stan Weiss]

Originally Posted by Formulajones

Yes you could say very close to a RAIV. It was a .474 lift intake and exhaust. 329 advertised duration intake and exhaust, and 232 @ .050. It was on a 113 LSA.

Worked really good in the W-31 350's and still popular today.

The 068 in question though doesn't even come close in comparison.

If you look back a few posts you see someone saying the RAIV cam will be a pig in a 350. That is why I pointed out the W31 which that I can remember was a very strong runner.

Stan

[Stan Weiss]

Originally Posted by pastry_chef

Summit 2800.
Advertised Duration: 278 int./288 exh.

It would interesting what tappet rise that advertised rating is at?

In a low compression engine I'm VERY concerned about when the valve actually opens and seats. Delaying intake valve close there is very bad!
Opening the exhaust valve earlier at low RPM hurts torque, as does closing the exhaust valve later.

The Comp HE268 lobe has 272.8 duration @ .0045 tappet rise.
but 218.6 @ .050 for breathing.

https://www.youtube.com/watch?v=m9dSIUFWNpg
14 flat is decent for a low compression stock head 350 Pontiac.. granted it has some good gears.
Running very close to the valve events Dynomation 6 said was the best from 2000 to 4500 RPM, in truth the program wanted 107 LSA but modelling was with headers.
I kept intake valve close and exhaust valve open the same, I presume the OP here is running exhaust manifolds.

Mike,
These were not measured by me.

2800
Intake 266.5 @ 0.006" - 204 @ 0.050"
Exhaust 279.5 @ 0.006" - 215.5 @ 0.050"

2801
Intake 275 @ 0.006" - 214 @ 0.050"
Exhaust 286 @ 0.006" - 225 @ 0.050"

Stan

[Formulas]

My 2800 and 2801 cam cards were not 100% informative I hand filled the 2800 in dont remember from where I got that info

I used both in a 350 with #47 heads automatic 2.73 gear

I used a 068 in a 350 with #48 heads 4 speed 3.36 gear

I used sig erson 204/204 @.050 .411 lift in 350 #11 heads 4 speed 3.36 gears

Now the 350 has #48 heads lunati 30706 cam 4 speed 3.73 gear no street time yet

[pastry_chef]

Originally Posted by Formulas

My 2800 and 2801 cam cards were not 100% informative I hand filled the 2800 in dont remember from where I got that info

Thanks.
For the 2800 card looks like 262/ 272 is printed for advertised. Much better than 278 / 288 from the Summit website.
I wonder if some of these differences are due to varied suppliers over the years.

Over nearly 7000 variations of valve events in Dynomation 6, all the best 5 had 61 ABDC intake close (7.5 compression 350 Pontiac).

[Formulajones]

Originally Posted by Stan Weiss

If you look back a few posts you see someone saying the RAIV cam will be a pig in a 350. That is why I pointed out the W31 which that I can remember was a very strong runner.

Stan

Yep agree. There were quite a few very strong small engines of the day with much larger camshafts too, that actually drove well enough to be sold as street cars to the general public with a warranty. The little 302 Chevy with a 254 @ .050 cam is one. That's even a more extreme example than what we are talking about here. The LT-1 350 was 242/254 @ .050. Even the smaller 327/365hp used the 254 @.050 cam that was later used in the 302. Tons of examples.

People want to talk about a RA IV 230 @ .050 cam being way to big for a 350, barely begins to tickle the surface.
In no way do I see an 068 being too big for a 350, that's crazy talk. I've run the snot out of that camshaft for years. It's puny in comparison.

But that kind of talk does not surprise me a bit coming from die hard Pontiac people.

[Jay S]

The larger duration numbers for those 2800 and 2801 are SAE numbers. Rocker arm ratios have an effect on those numbers. Rated at .006” at the valve. The numbers Stan posted are pretty close to what they are at .006”tappet lift. The lower numbers like the 262 and 272 are advertised acts like numbers some picked in a board room.

[77 TRASHCAN]

Jon Hardgrove ( Carbking) has a 041 cam in his 350 Ventura/GTO.

[Formulas]

Simple honest question how many of you have actually actually owned / experienced a P350 / 068 combo ?

P350 threads are always a slow train wreck by experts who have never wrenched on them or lean on almost the same examples full of conjecture

[72LuxuryLeMansLa.]

Originally Posted by Formulas

Simple honest question how many of you have actually actually owned / experienced a P350 / 068 combo ?

Not me. I have 100,000 miles on a low compression '72 350.......

[MarkS57]

Originally Posted by Sirrotica

Many years ago we would put a set of 400 high compression heads on a 350 and stick an 068 cam in it when we ran out of larger displacement engines.

I did this with 16's. The 406" valve lift of the 068 sort of keeps you out of trouble with the bore size. Really a sweet running engine. Heck, I wouldn't even mind trying out a 744, same valve lift.

From my recollection, the W31 was a 308 cam vs the W30 328 455 cam.

[Sirrotica]

Originally Posted by MarkS57

I did this with 16's. The 406" valve lift of the 068 sort of keeps you out of trouble with the bore size. Really a sweet running engine. Heck, I wouldn't even mind trying out a 744, same valve lift.

From my recollection, the W31 was a 308 cam vs the W30 328 455 cam.

I guess when someone points out the advantages the engineers built into the Pontiac 350, plus real time experiences, the small Pontiac isn't as bad as the critics claim it is.

As I already posted i've used the 350 Pontiac in many different applications, it's not disappointed me so far.

[Jay S]

Originally Posted by 72LuxuryLeMansLa.

I have a Summit 2800 flat tappet that Jim Hand told me was perfect for a low compression stock 350. You can have it for the cost of UPS..... Message me.

Can’t beat that!

Go this order…first…gear change to 3.08-3.23
Second….2.5” mandrel exhuast system
Third….4 bbl q jet
Fourth….cam change to that 2800

I suggest not try the cam swap first. I remember a buddy put a 4 bbl on his 67 326 lemans with 2.56s and a st300 2 speed. It was hilariously just as slow as it was with the 2 bbl. He did gain on the 4bbl sound though……floor it and……wwwwaaaaaaaaahhhhh……..

Some good gears that would have kept the engine from laboring so much and it would have been a different car….

I did a 260*@.050” solid roller in a lowish compression big valve 350. I remember it being pretty awesome.

[Sirrotica]

I suggest not try the cam swap first. I remember a buddy put a 4 bbl on his 67 326 lemans with 2.56s and a st300 2 speed. It was hilariously just as slow as it was with the 2 bbl. He did gain on the 4bbl sound though……floor it and……wwwwaaaaaaaaahhhhh……..

Some good gears that would have kept the engine from laboring so much and it would have been a different car.

Same car and powertrain, 326, AFB from a 65 389, dual exhaust, Finally the ST 300 bit the dust, and I swapped in a long tail T 400. Even with the 2.56 axle getting the extra gear with a 2.48 first gear made it a different car.

Pontiac used 2.56 gears in a lot of their base models, with a 2 speed they were dogs out of the hole, with a 2.48 first gear makes it a much better car from a standstill. Not a race car, but much better than the 2 speed.

[Shiny]

Haven't seen Squidward on here lately but he had a lot of experience with 350s and his posts were always useful. Here's an example:

http://forums.maxperformanceinc.com/...89&postcount=7

My car has it's original 350 2bbl with 11 heads. I installed a 2800 cam and quadrajet but have yet to drive the car after what... 20 yrs of looking at it?

When I do try to get it running, I think the 11 heads may go away as I understand the CR is likely under 8 despite the "specs" that claim 8.8. After reading this forum for years, I doubt the 2800 will add any power and may actually hurt the low-rpm torque...

Where's the data? Or at least somebody that measured the results of a low-compression 350 cam change?

[SD455DJ]

I'll have to ask Dan to send me the dyno results of a '69 350HO for an automatic application (067 cam) he was building for the pure stock drags. I don't think is was maxed out at 12.0 compression.

Dennis

[steve25]

It needs to be noted that the Olds W31 cam has only 82 degrees of over lap to the RA4’s 87.
The Olds heads could not compare to the valve sizes in the 69 48 casting either!
Less over lap and smaller valves makes for more port velocity and better street manors.

[geeteeohguy]

I agree with Brad and Steve25 on all counts. In the past 40+ years have run a 326 in a '65 GTO with a 4 speed and 3.23, and it almost kept up with my '66 Coronet 44 4 speed 3.23 rear gear car. Not even a car length. The 326 had a Crane Fireball cam, tube headers, and a Holley 750. A friend had a '65 GTO with a 350 that was stock, but with a '66 tripower bolted on and a TH350 trans with a 3.55 rear gear. That car would pin you in the seat. Pontiac 326/350's are excellent, durable, and under-rated engines.

[72LuxuryLeMansLa.]

Originally Posted by Shiny

Haven't seen Squidward on here lately but he had a lot of experience with 350s and his posts were always useful. Here's an example:

http://forums.maxperformanceinc.com/...89&postcount=7

My car has it's original 350 2bbl with 11 heads. I installed a 2800 cam and quadrajet but have yet to drive the car after what... 20 yrs of looking at it?

When I do try to get it running, I think the 11 heads may go away as I understand the CR is likely under 8 despite the "specs" that claim 8.8. After reading this forum for years, I doubt the 2800 will add any power and may actually hurt the low-rpm torque...

Where's the data? Or at least somebody that measured the results of a low-compression 350 cam change?

this was the thread where I decided on the 2800. It wasn't to add power but to raise cylinder pressure for a little more efficiency without changing heads/springs...

https://forums.maxperformanceinc.com...d.php?t=622996