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Discussion Starter #1
I am working on setting up a tranny for my '68, and while talking to the tranny guy today brought up the issue of what stall speed I should use.

He says that a 2500 stall would be the max I should go to keep the ride comfortable and avoid overheating problems. What do you guys think? Oh, the tranny in question is a 700 that is very beefed up.

In a related side question, do you think my engine will require above a 2500 stall? I haven't picked the cam yet, so obviously it will be difficult to answer this question, but here's what I have so far:

Performer RPM Aluminum heads, 2.02 1.60 valves, 64cc straight plug.
Ported and polished a lot...
Victor Jr. intake
5/16 Pushrods
750cfm Holley Double Pumper
9.5:1 Compression
All on a 4 bolt 350 engine stroked to 383.

Does anyone have any cam suggestions for this?

I know there's a lot of information missing on the engine, if you guys give me some blanks to fill in I will do my best.

Kyle
 

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American speed did a buildup in a mag a few years ago with very similar parts...they used a comp cams 286 magnum cam and got 460 hp and I think 480 pounds of torque. They used a performer rpm intake instead of the victor jr. though...so your probably looking at 475hp/480 ft-lbs...with some 3.73 gears and the 700's low 1st gear, this thing would be brutal. With this cam I would use no less than a 2500 stall. Of course this is just a suggestion...it really depends on what YOU want out of your car.

------------------
375hp 78 Chevy truck
77 Chevy Nova
95 Chevy Lumina 3.4L
and building a 78 Nova
 

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Discussion Starter #3
I was thinking of using a cam that would be suited for 3.90 gears instead of 3.73, but I assume the difference wouldn't be too great.

Do you suggest I use a cam/gear matchup for 3.73's instead of 3.90's? I am interested to know.

Kyle

[This message has been edited by KiZile (edited 06-19-2001).]
 

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With the 700 trans, you will hardly notice any difference between 3.73 and 3.90 gears. The lower first gear will give you plenty of pick up while the overdrive will make either gear pretty nice on the highway. That being said, most camshafts wouldn't notice much difference either.

What cam you pick really depends on what you want to do with the car. Going by the fact that you have the single plane intake, you probably want a longer duration cam to match in which case a 2500+rpm converter may suit you well. If you want this build to see lots of street cruising and less full throttle blasts, get a somewhat shorter cam and a 2000-2500rpm converter. With the 700 trans though, get a lockup converter. This will pretty much nullify the overheating issue.

Also on cam selection... what kind do you want to run? Hydraulic? Solid? A roller of some sort? If you are going hydraulic and want to run a 2000-2500rpm converter, look into something like Comp's XE274 I would think. If you want more cam, go with the XE284, but you may need a looser (higher stall speed) converter.

Also keep in mind vacuum with your cam if you are running power accessories. If you run a really big cam, you will need a vacuum resevoir or possibly a pump.
 

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With the 700 trans, you will hardly notice any difference between 3.73 and 3.90 gears. The lower first gear will give you plenty of pick up while the overdrive will make either gear pretty nice on the highway. That being said, most camshafts wouldn't notice much difference either.

What cam you pick really depends on what you want to do with the car. Going by the fact that you have the single plane intake, you probably want a longer duration cam to match in which case a 2500+rpm converter may suit you well. If you want this build to see lots of street cruising and less full throttle blasts, get a somewhat shorter cam and a 2000-2500rpm converter. With the 700 trans though, get a lockup converter. This will pretty much nullify the overheating issue.

Also on cam selection... what kind do you want to run? Hydraulic? Solid? A roller of some sort? If you are going hydraulic and want to run a 2000-2500rpm converter, look into something like Comp's XE274 I would think. If you want more cam, go with the XE284, but you may need a looser (higher stall speed) converter.

Also keep in mind vacuum with your cam if you are running power accessories. If you run a really big cam, you will need a vacuum resevoir or possibly a pump.
 

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Discussion Starter #6
Firt off, it will be a hydraulic roller cam. After further consultation with my engine guy, he suggested using a 2500-2700 stall. Even though the tranny guy said I shouldn't run over 2500, I don't think that will be too bad.

Is there something between the XE274 and XE284? Or would I be able to run a 2500-2700 stall with the XE284? If so, then that is probobly the cam I should run. Since I won't be doing a ton of driving in it (I live 300 yards from where I workd), I am willing to sacrifice some drivibility for performance.

Vacuum hasn't even crossed my mind...it won't have air conditioning, but I will be running a CD player all the time with decent sized speakers. I was considering upgrading to even larger speakers, but maybe I should look further into the vacuum issue first?

Kyle
 

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just for info: the same converter "advertised" at 2500 rpm will probably stall at 5 different rpm's in five different cars....it depends on alot of factors. so 2500 or 2700 are probably gonna be pretty much the same.
 

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the vacuum shouldn't have any effect on electrical systems. By power accessories I meant power brakes and such. The XE line I was mentioning are regular hydraulic flat tappet cams. If you want to pick out a roller, check out the XER line. www.compcams.com

Jblake also makes a good point. A rated stall speed isn't set in stone. Different engines will have different stall speeds in front of the same converter.
 

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Discussion Starter #9
Cool, thanks for all the tips guys. I have been thinking of putting in power brakes, or at least disc brakes (are they the same thing?), but the teenager in me will worry about that later! First get the car going, then figure out how to stop it.

I assume I could put a reservior in as needed if i get around to putting in power accesories right?

Kyle
 
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