Thought I would share this with you guys..
Have a very good friend that has a beautiful gold 69 SS396 (some of you know him from LVD) Anyway,he goes to the track once in awhile and runs his car..we got a basically stock 350 HP 396 with headers to run a 14.13 @94 MPH..motor ended up having some issues and discovered it also had a 454 flexplate on it when we pulled the motor out! No wonder why it wouldn't MPH..anyway,he bought a rebuilt unfired 454 with Speed Pro hyper flat tops and 049 heads..ended up using the 238/248 @ .050 .540/.540 114 LSA Summit cam left over from a 396 project...I gotta tell you..in an 8 to 1 454 with an Airgap RPM,older 11" TCI 3200 flash stall and a 3.07 posi this motor rocks...it sounds incredible thru the 2.5" Flowmaster kit w/Summit turbo mufflers and pulls hard..you would NEVER know this is an 8 to 1 motor..only downside is,of course..vacuum.
Pulls 10" @ 1100 RPM's and 5" in gear around 700-750 RPM's
He came by the house with the car last night and took me for a ride and then I drove it..I was impressed as well.Pulls real hard and lights the tires up all over the place! We'll be going to the track with it in a few weeks..I will post the results.
here is a pic of the car:
http://www.chevelles.com/showroom/data/500/medium/69ss6.jpg

Awesome, Glad he has it back together Car Looks Great as usual. Tell Mark I said hello..

Tom

I would have thought that cam would have been a tad big for that combo. Especially with the rear gears, but what do I know.
Nice car also.:thumbsup:

Jim,I was absolutely amazed at how much low end torque this car has along with the throttle response...its very snappy when it revs up and just sounds awesome.My friend wanted that "lopey cam" sound and he got it all right :D
Other than low vacuum this combo runs great.

Sweet ride, building a similar 454 myself for my '70 SS project, only going with Edelbrock aluminum heads and SpeedPro 110 dome coated hyper pistons. So would you recomend that much cam again given having power brakes.

So would you recomend that much cam again given having power brakes.

absolutely.
The 238/248 Summit grind is an "old school" and there are certainly much better choices.This is what we had in stock so to speak and he wanted to use it.And it works well.This motor has more "snap" to it then a similar 454 that I put together using the 228/238 cam (next step down) and closed chamber heads.We ended up with about 9 to 1 using a stock untouched 1973 454 shortblock.

That particular cam has units leaving the dyno room with 500 HP and over 500 Ft.Lbs. Torque with most stock LS-6's but using only a 10:1 C.R. I'm not certain I would choose that for an 8:1 unit. I'm not even certain about getting involved with a C.R. that low on any N.A. piece. Moreso now that the available fuels at the pumps will be able to handle some slightly higher C.R.'s.

I have a bunch of these cams in units running around. Very popular grind and easy on the valve train components! Using spring pressures at the 140# closed and 340# open at .570" lifts they still pull strong up to 6500 WITH no lightweight valves, standard 3/8" stems. This is a proven fact with us at the track! The heads need in the area of 300 CFM to pull it off!

Thanks, Gary in N.Y.

P.S. Just to add here, that very cam with the unit in proper tune will run with approx. 14" of vacuum and handle the power brakes with no problem.

Wow! Who says "old school" stuff isn't still applicable! That cam sells for $55.95 thru Summit and with a 114 ICL, it would probably even like a bit of laughing gas. Very cool and great looking car to boot! Love the budget minded stuff.

seems like that vacuum is low. has he optimized the timing at all? it would like a lot of initial, maybe 16-18 degrees with 20 mechanical and 15 more vacuum advance. if he's running 8 or 10 that's what's killing his vacuum. more initial will make it fell snappier, more responsive around town. this is the upside of running low compression, gives you lots of room for tuning and not real sensitive to occasional load of bad gas.

We're running 20* base and 38* total by 2400
There is no absense of low end torque as I mentioned.
It pulls better than the 9 to 1 motor with the smaller cam!
Gary,thanks for the info as always :thumbsup:

I have an 8 to 1 454 with 049 heads that was built 20 yrs. ago. It has bigger valves and I think a 268 272 adv. crane cam. With a 331 gear and no traction it went 14.09 @104. It has a q jet and a Weiand dual plane. It idles smooth at 650 in drive.

seems like that vacuum is low. has he optimized the timing at all? it would like a lot of initial, maybe 16-18 degrees with 20 mechanical and 15 more vacuum advance. if he's running 8 or 10 that's what's killing his vacuum. more initial will make it fell snappier, more responsive around town. this is the upside of running low compression, gives you lots of room for tuning and not real sensitive to occasional load of bad gas.

Well put. There's not much tuning on these engines setup like these. Just lock up the distributor and set the timing at 34 or 36 on the tag and forget about it. Simply change plugs and oil once in a while. You can get away with this on anything at 10 to 1 or less with a reasonable cam inside.

You won't see nearly enough vaccum with the stock timing specs.

Harry P Hunter

We're running 20* base and 38* total by 2400
There is no absense of low end torque as I mentioned.
It pulls better than the 9 to 1 motor with the smaller cam!
Gary,thanks for the info as always :thumbsup:

Hi Chris, no problem!

I believe you are actually familiar with one of these units. I have time slips for a couple of them, one I have runs down in the South and I also have a local one here. These are the only two I personally have the slips for, but I have a few similar ones that don't see the track.

Thanks, Gary in N.Y.

P.S. In "bone-stock" trim, with lower compression, 10:1, the LS-6 with no
"tricks", stock-stroke, no porting, no headers, will run 12.50's at 112 MPH on legitimate street tires AND on straight 93 octane, no mix! This is also with the stock convertors and stock rear gears. Car probably tips the scales at or above 4000# with the driver on board and a tank of fuel.

Double P.S. "Happy Easter"!

Kinda surprised it drops from 1100 to 700-750 in gear with a 3200 stall. That's the interesting thing with my 10" 3000 stall. Motor idles at 900 in neutral, maybe 850 in gear. Wonder is this also has to due with the increased efficiency of higher compression.

On another note, have to ask - - was the cam degreed or just installed dot to dot.

On another note, have to ask - - was the cam degreed or just installed dot to dot.

dot to dot.

This got me curious.....I started going through the Summit web site and those cams are $79 bucks and change. HOWEVER, also listed is part number SUM-CCRN09, a Summitt cam, its 210 bucks!!!

What is going on here.

I don't see that part #, looks like some of it is missing. however, I'd guess that it is a Comp Cams hydraulic roller, roller are more expensive. You don't want to own one of the CC cast iron rollers, their problems are well documented on this site and others.

Sorry, messed up.

SUM-CCRN209

Its a Summitt cam, flat tappett.

I bet that old Summit 296/238/306/248 cam would run a whole bunch better in an 11.75 to 1 CR. engine like it was meant to be ran in.

But whatever, glad it run's as strong as it does at that low a CR. for you...

pdq67

Kinda surprised it drops from 1100 to 700-750 in gear with a 3200 stall. That's the interesting thing with my 10" 3000 stall. Motor idles at 900 in neutral, maybe 850 in gear. Wonder is this also has to due with the increased efficiency of higher compression

Joe,my combo idles about 900 in neutral/park and drops down to about 750-700 in gear with a B+M 2400 Holeshot that flashes to 3000-3100

I bet that old Summit 296/238/306/248 cam would run a whole bunch better in an 11.75 to 1 CR. engine like it was meant to be ran in.

Sure it would..but it works well as is.. years back,we stuffed an L79 cam into a stock 305..car ran awesome and hit the 14's at the track..we'll have a timeslip in a few weeks for this 454..a fellow TCer used this same cam in a stock 396/402 and was turning low 13's @ 103 with 3.31's and an auto..not saying it'll be better than that..heck,my friend would love to just get into the 13's and LOVES the idle of the 238/248 cam...it sounds very deep even with the 8 to 1..must be from having the exhaust crossovers eliminated with the RPM Air Gap.

My car I mentioned earlier would run mid 13's with some drag radials. Get your tune up dialed in and Im sure you will atleast be that good.

Many times those drops in vacuum/rpm are caused by advance weights on too soon, or the vaccum can losing enough Hg" to give any vaccum advance.

I dont think Mark has these issues,just sayin'. Mark must've gottn hisself a good rebuild.

Summit Cam and Lifter Kits Cam and Lifters, Hydraulic Flat Tappet, Advertised Duration 286/ 296, Lift .534/ .553, Chevy, Big Block, Kit

It's a kit with lifters, not just a cam.