348 cam choices

[Tom Kochtanek]

Looking for some expert guidance in choosing a camshaft configuration for the following 348 stroker build:

• Block is 1960 FA 348 block, bored .060” or 4.185”
• Crank is stock 409 (standard/standard) with new replacement BBC rods
• Pistons are Aubrey’s design for the stroker 348 with 409 crank; Forged, made by Ross
• Displacement is approximately 364 cubic inches
• Heads are vintage 1960 1147s with larger valves and high perf springs (replacements for 690s)
• Intake will be tripower with Rochesters
• Want to attempt to use stock tripower valve covers over roller rockers, but we’ll see…

I would be happy with more than 350 horses and commensurate torque numbers over 400.

This engine will be placed in a someday-to-be-restored 1961 Belair Sport Coupe. It will be a street driven vehicle. I am not looking to race this particular car. Engine will be coupled to a standard shift transmission, either a short-lived Saginaw three speed with column shift (cool, but not very functional), or a floor mounted four speed BW T-10. Rear end will be positraction, currently with 3:36 gears. Wheels will be stock 14 inchers and tires will be street radials. Yes, it will have dog dishes :).

My question is related to camshaft choices. What would I be looking for to get this level of performance in a street driven car?
I have a preference for solid lifters, but with what specs?

Thanks in advance for your input. I look forward to making a good decision on this one!

Cheers!
TomK

[Richard/SIA]

When I checked the chart for my .030 over 348 with 409 crank I thought it stated a result of 377".

With .060 overbore I would expect you to better that by a couple of inches.

Sorry I can't help with the cam, but the displacement just looked wrong.
Maybe not enough difference to matter. :dunno

[Dick MacKenzie]

Tom,
I think Richard is correct. I get 385 c.i. by using the following formula.

Bore 4.185 X Stroke 3.5 X Pi (3.141593) X number of cylinders (8)

4.185 X 3.5 X 3.141593 X 8 = 385.1579 c.i.

I like it! :brow BUT, can't help with the cam either! :dunno

[Tom Kochtanek]

I like the sound of "385" much better that "364". Must've done the arithmetics wrong :).

Aubrey and I have done business recently (hence the cool pistons!) and I warned him I'd be looking for options on the cam. He did the one for my 409 stroker, and I was/am very pleased with that design. I'm hoping he comes up with another strong recommendation. With the little experience I have, these dynamics stifle me a bit...

Took the parts (pistons and crank) to the machine shop today, gonna have this one balanced and assembled there this time. I did the last one, but they get this one... Oddly, we got the pistons to weigh a bit different than what Ross quotes, just 3 grams, but enough to make me wonder about their calibration (the local machine shop).

Cheers!
TomK

I'm not sure "She's real fine, my 385" is going to make a record label, but that's what we're dealing with here.

[Richard/SIA]

You write the rest! :rofl

Me, I'm going to be in 377" heaven, run the 1/4 in eleven!
This is too easy, I must need sleep. :yawn:

[RCE1962]

Hi Tom

Here's an old thread on a 348 stroker with one of Aubrey's cams.

http://www.348-409.com/forum/showthread.php?t=8147&highlight=gusto

Plus....and an old thread on CID combinations for poked and stroked 348/409s

http://www.348-409.com/forum/showthread.php?t=12330&highlight=rce1962

Your project sounds much like something that I would like to do as well. I have the 348, the three-deuce set-up but in place of the 1147’s I have a good set of re-worked 817’s with the big valves and screw-in studs. I will be really interested on how your project turns out.

P.S. I used some metal valve cover spacers for the roller rockers on the 409 and was able to use the stock valve covers. Not really noticeable when painted chevy orange as well.

Ron

[Tom Kochtanek]

Nice!

Are those 3/8" spacers?

I see some on Ebay for $99, is that about right?

Will keep you posted as things develop. No big hurry, the body is still a year behind the engine. Currently working on block sanding the body on the 1961 Bonneville. Hey, maybe I should test that stroked 348 in the Pontiac, call it "Canadian" :).

Best,
TomK

[Phil Reed]

• Heads are vintage 1960 1147s with larger valves and high perf springs (replacements for 690s)
TomK

I hope you didn't use the 690 valve springs!! You are stuck with the 5/16" pushrods with the 1147 heads and you will probably bent all the pushrods with those springs!!!!:dunno:dunno:dunno

[Tom Kochtanek]

Man, I did those heads last year, didn't know what they'd be on at the time, maybe I wasn't thinking straight. Better check and see which springs I used.... Easy to change. Didn't pin the studs, think I might go back and do that as well...

Thanks for mentioning that!

Best,
TomK

[Ronnie Russell]

I am using 3105D Isky springs with 5/16 pushrods. .080 wall -chromemoly. No problems. I was also using the valve cover spacers. They were borrowed. Owner made me give them back. The nerve of some people. replaced with double neoprene gaskets glued together with rubber cement. Scorpion rockers. They cleared just enough, at least I don't hear any noise. Always more than one way to skin a cat.

[CDNpontiac409guy]

Who the heck is this "Aubrey" guy anyway ?:dunno

Tom, I'm thinking that the little triple 2 barrel won't feed this enging to a singing RPM, so maybe a little more civilized cam than that in the big engine:yawn::p

Here's one:

M-235578D

Gross lift.......... .578"/.592"... less lash = .560" / .574"... with 1.7 roller rockers, you're down to about .545" / .569"
Adv duration.... 270/280
Dur @ .050"..... 235/242

Put this on a 108, and you'll have a pretty "good" idle, and be shifting around 5600-5800.

just a thought

[RCE1962]

Nice!

Are those 3/8" spacers?

I see some on Ebay for $99, is that about right?

Will keep you posted as things develop. No big hurry, the body is still a year behind the engine. Currently working on block sanding the body on the 1961 Bonneville. Hey, maybe I should test that stroked 348 in the Pontiac, call it "Canadian" :).

Best,
TomK

Tom the exposed area of the valve cover extensions, shown in the photo attachments, is only 3/16ths. I seem to recall that I paid about $65.00 for them.

....But...then again...I just looked up the listing, for this item, on the Show Cars Web Site.

5962 348/409 Valve cover extensions 3/16 steel... Ea. $24.75

Better check how much clearance you will need.

The cam used in my 409 is the Z-11 cam from Isky.


Ron

[chevytaylor]

Who the heck is this "Aubrey" guy anyway ?:dunno

Tom, I'm thinking that the little triple 2 barrel won't feed this enging to a singing RPM, so maybe a little more civilized cam than that in the big engine:yawn::p

Here's one:

M-235578D

Gross lift.......... .578"/.592"... less lash = .560" / .574"... with 1.7 roller rockers, you're down to about .545" / .569"
Adv duration.... 270/280
Dur @ .050"..... 235/242

Put this on a 108, and you'll have a pretty "good" idle, and be shifting around 5600-5800.

just a thought




Aubrey, this might be a silly question, but why run the 1.7 rockers instead of 1.75 and loose lift? :scratch
Carl.

[CDNpontiac409guy]

Aubrey, this might be a silly question, but why run the 1.7 rockers instead of 1.75 and loose lift? :scratch
Carl.


Valve springs, Carl. Coil bind could become an issue. Not to mention, all of the 1.75 roller rockers that I've seen so far, are of sub-standard quality. In the 1.7, you can get the very best of the best.