What "Roller" Cam Should I Use?

[Zippie#7]

O.K., I was told that if I give the proper information to this question, I would likely receive some good info from the great people here!.

Well, here goes: I am in the process of building a 340-40 over with a 3.58 crank, KB-40 over pistons, stock rods, a single-four manifold, TQ 440 carb, 4-spd trans and 4.30 8-3/4 rear. This will be used inmy 70-Dart and will be used for light street and light track duty. (fun car).

My question: What would be a good "Roller" cam for this build?. If you take the time to answer, Thanks.

 

[1968FormulaS340]

What heads?

What head work done?

What specific intake manifold?

What compression?

You didn't mention headers. Are you running headers?

Do you want a solid or hydraulic roller?

(You will also need new valve train components…….. Springs, Rockers and assorted parts)

 

[EL5DEMON340]

Not much info, what CR, what heads, what do they flow, what intake, i would say with those parts you are going to stay right around 6k for max rpm. what kind of track? Bullit is a good cam grinder

 

[1970Duster]

Well whatever roller cam you use just get one with a cast iron gear on it

 

[Zippie#7]

Heads, x with 202-160 valves no port work, intake, edel. with open plentium. Not sure on the compression, yes will be running headers, ITT? Hydraulic roller and roller lifters.
Springs will match the cam requirements. Track, 1/4 mile. I am new at this, so if I sound dumb, I am!.

 

[1968FormulaS340]

I am new at this, so if I sound dumb, I am!.

You only learn more by asking questions. Blindly getting a cam without knowing what to get would have been dumb.

You are already ahead of the game.

I don't know what cam you should get but I did know the other guys would want more info.

 

[1970Duster]

Use stainless steel valves (I used Ferrea Single groove), if you go to summit racing now you can order Doug's headers for cheap like 500, save 200 or so over tti headers

 

[rumblefish360]

I am new at this, so if I sound dumb, I am!.

LOL, relax and no worries.

The car sounds like it has been set up preety well so far. I'll ASSUME (A dangerous word...) the compresion is a reasonable one and make a couple of suggestions based on the limiting factor, the heads, which will need to have work done on them just to run the cam, never mind effectivley.

The heads will have to have work done on the spring pad area. (Where the springs sits on the head) so the spring fits and the valve guide height will need to be shortened. (For the very high lift vs. stock lift)

http://www.summitracing.com/parts/CCA-20-814-9/

(IMO, a good porting while it is there with Ferrea valves would be worth every penny spent!)

This build sounds alot like the one I have slated to do next.

 

[Zippie#7]

To all, the info I received in this thread was all good info to me, now I know what direction I need to go in. Thanks to everyone, plus a big thanks to Rumble.

 

[rumblefish360]

On behalf of the crew and myself, your welcome.

Your comp ratio needs to be know by the way.

If it is low, I'd run a smaller cam of approc. 230 @ 050 in duration.

if it is stock, I think you'll have trouble finding a roller to work well.

 

[Zippie#7]

With the little bit more stroke with this crank that I am using I am hoping that will drive these KB pistons up some in the bore. Maybe I will have to shave the heads some also?.
The pistons do have valve releafs in the tops, so I have so play there. When I start to put this "thing" together I will know better about the compression I hope.

 

[rumblefish360]

So you'll have a 374 cube engine. With the 360 crank in a .040 overbored 340.

What KB slugs are they?

 

[Zippie#7]

KB243-40, Hyper-flat, 4.070 in. bore.

 

[rumblefish360]

Those will not work, there for a 3.31 crank stroke, not a 3.58 stroke. There height is to tall I beileve. Unless someone knows differently.............

 

[Zippie#7]

I will have to look into that, if that is the case, I will have to order new pistons! Thanks for the info Rumble, I will keep you informed.

 

[rumblefish360]

Yea, double check me on this.

If your 340 is overbored .040 and uses a 3.31 crank, AKA stock crank, I beileve you can use them.

If you install a 360 crank @ 3.58 into a 340 engine, then you would just use 360 pistons at the bore size of the block.

this combo is an old time home shop stroker for the 340 and works very well. Biggest bore and stroke combo from stock parts that you can get without getting fancy on crank grinding wacko overbore sizes.

 

[Mad Dart]

Yea, double check me on this.

If your 340 is overbored .040 and uses a 3.31 crank, AKA stock crank, I beileve you can use them.

If you install a 360 crank @ 3.58 into a 340 engine, then you would just use 360 pistons at the bore size of the block.

this combo is an old time home shop stroker for the 340 and works very well. Biggest bore and stroke combo from stock parts that you can get without getting fancy on crank grinding wacko overbore sizes.

He will need to have the 360 mains ground down to 340 size also, no?

 

[rumblefish360]

Yes, unless he purchased the crank new with the 340 mains and the 360 stroke.

 

[rumblefish360]

Like these;

http://www.summitracing.com/parts/SCA-934010/

or

http://www.summitracing.com/parts/SCA-434010/

 

[Mad Dart]

Yes, unless he purchased the crank new with the 340 mains and the 360 stroke.

I hear ya, was just pointing out that they are different in Stock form is all.

Carry on!

 

[rumblefish360]

He he he, gotcha. I answered a question, that's all. Your sentence did end with a "?" mark. ;)

 

[Zippie#7]

Morning rumble, I am on my way this morning to the machine shop to make a change in crankshafts, I now have two cranks at the shop one stock and this other 3.58. and yes, this 3.58 dose have the 340 jernals, shop sized it for me and they said it was 340.
This crank I will keep for a third build for a 340 block I have in my shop, and at that time I will get 360 pistons for that build. This machine shop that I am working with is a NAPA shop that dose great work and I trust them. So, this change will not be a problem for them. I would like to thank you again for all the good info and also thank everyone else for giving me help. I will keep you informed on my builds as they go. ZIP.

 

[Zippie#7]

O.K. back from the machine shop, the guy I bought the crank shaft from lied to me, this new crank is not a stroker crank but is a "new" steel replacement crank for a 340, so, the pistons will fit. The mach. shop took both of my cranks I now have there and miked them up and they were both the same!!! Good news bad news, thought I had a little stroke there, but no just the same old 340 stroke.
But, this will change my choice of camshaft I would suppect and when I have the "proper info, compression, ect. I will be back. Thanks guys, I have learned a few new things these last couple of days and thats good. Thanks, Zip.

 

[rumblefish360]

It would react a little more radical in a smaller engine. Idle wise and need more stall since it is down 30+ inchs. You could still use it being the rest of the car has the gear to properly use it and use it well IMO.

You'll need a 3000 stall converter for this cam and car combo.

 

[Zippie#7]

Thanks Rumble, I will keep you informed. your info has helped me alot.