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Small block racers, need help with cam choice #3082132
10/01/22 07:41 AM
10/01/22 07:41 AM
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gregsdart Offline OP
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A buddy has a 360 + .030 3.58 stroke motor with the wrong cam in it, IMHO. IT IS A 528 LIFT MOPAR flat tappet solid cam with a 112 LSA, in at 106. The car is a 63 dart, 3.91 gears, 3800 stall (?) Weighs about 3400 with driver. Heads are 308 castings, mild bowl work. 1 5/8 to 1 3/4 step TTI HEADERS. rpm intake, 750 holley. Compression is weak, 8.5? Been dynoed on a chassis dyno, timing 30 total.Test day yesterday, yielded 12.45 to 12.49 at 106.5 no matter what we tried. The car runs very con consistant, hooks on 28x9 slicks, 1.72 60 ft.
I found a circle track cam from Comp, thier smallest, at 260, 266 @ .050 106 LSA, .560 lift. Opinions on this cam? Or what would you pick?

Last edited by gregsdart; 10/01/22 07:44 AM.

8.77 153 mph best, 3055 lbs 528 indy 440-1 alky
Re: Small block racers, need help with cam choice [Re: gregsdart] #3082134
10/01/22 07:58 AM
10/01/22 07:58 AM
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It’s definitely gonna hook. It doesn’t have any cylinder pressure.
Low compression and 112 LSA are going to contribute to soggy 60 foot times, and a negative effect on ET
I would opt for a much narrower LSA cam, something 108 or 106.
With enough convertor, that cam can really be stepped up.
The 10 to 1 stock stroke 360 I took out of my car two years ago had a 260@50 cam on a 106, in at 102. Car weighs 3350 with me. Went 11.20’s at 118+ with very mild edelbrocks on it, air gap, 1 5/8 headers

That cam, several buddies have since bought and used with great success.
It’s from Howard’s. 260/264. 565/565, 106 LSA, to be installed at 102.
Great cam, nice chop, very good power, doesn’t have the more radical lobes like a lot of the stuff they grind for Hughes.
I run the cam in my 418 now. I use the Howard’s solid lifter with the oiling hole in the face. 3 seasons in the 360, two seasons now in the 418.

Last edited by B3422W5; 10/01/22 08:04 AM.

69 Dart GTS A4 Silver All steel, flat factory hood, 3350 race weight
418 BPE factory replacement headed stroker
Best so far, 10.68 at 124.48
1.44 best 60 foot.
6.76 at 101.63 best 1 /8

Re: Small block racers, need help with cam choice [Re: gregsdart] #3082159
10/01/22 09:43 AM
10/01/22 09:43 AM
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If the car is being raced with closed exhaust, carefully consider how much overlap you really want.

Imo, a 260@.050 cam for an 8.5:1 360 will want a pretty loose 8” converter and enough gear to turn 6500+ thru the traps.


68 Satellite, 383 with stock 906’s, 3550lbs, 11.18@123
Dealer for Comp Cams/Indy Heads
Re: Small block racers, need help with cam choice [Re: fast68plymouth] #3082164
10/01/22 09:58 AM
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Originally Posted by fast68plymouth
If the car is being raced with closed exhaust, carefully consider how much overlap you really want.

Imo, a 260@.050 cam for an 8.5:1 360 will want a pretty loose 8” converter and enough gear to turn 6500+ thru the traps.


Good points Dwayne, it definitely would want some convertor, and agree about closed up exhaust. I run Kooks muffs on mine, but they are basically dyno max bullets.
Just depends on what the guy wants to do with the car

Noticed too the car has 28’s on it. Must be at least minitubbed to fit that tire.
My brother has a 66, 26 inch tire is the biggest that will fit without modifications.

Last edited by B3422W5; 10/01/22 10:01 AM.

69 Dart GTS A4 Silver All steel, flat factory hood, 3350 race weight
418 BPE factory replacement headed stroker
Best so far, 10.68 at 124.48
1.44 best 60 foot.
6.76 at 101.63 best 1 /8

Re: Small block racers, need help with cam choice [Re: B3422W5] #3082263
10/01/22 01:59 PM
10/01/22 01:59 PM
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When you’re chasing ET, the cam & converter really need to be on the same page........ along with everything else.


68 Satellite, 383 with stock 906’s, 3550lbs, 11.18@123
Dealer for Comp Cams/Indy Heads
Re: Small block racers, need help with cam choice [Re: gregsdart] #3082284
10/01/22 03:04 PM
10/01/22 03:04 PM
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All the SB Mopar racers I knew who ran in NHRA stock class, regardless of which C.I. motor, liked and used cams ground on a 102 to 106 LSA and installed then from 2 to 6 degrees advanced on the intake lobes scope wrench up
They also didn't like much total ignition advance, no more than 32 degrees total rev up shruggy


Mr.Cab Racing and winning with Mopars since 1964. (Old F--t, Huh)
Re: Small block racers, need help with cam choice [Re: Cab_Burge] #3082379
10/01/22 09:31 PM
10/01/22 09:31 PM
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gregsdart Offline OP
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Two things I didn't mention. Setting the shift light to 5500 was the best, 30 degrees total also.
I am trying to convince my friend to put a K1 4.125 stroke crank in it with 5.85 chev rods. It would be 421 cubes and add 1.2 points compression using the same pistons. Add that 260/264/106 by . 560 lift cam and it ought to be a mean dog rather than a pup. Thoughts on that idea?


8.77 153 mph best, 3055 lbs 528 indy 440-1 alky
Re: Small block racers, need help with cam choice [Re: gregsdart] #3082381
10/01/22 09:37 PM
10/01/22 09:37 PM
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Another thought, move the 112 cl cam to 102, from 106.5, and crank in the lash to add some duration and lift. Any thoughts on that? That would be a basic band aid, but cheap.

Last edited by gregsdart; 10/01/22 09:39 PM.

8.77 153 mph best, 3055 lbs 528 indy 440-1 alky
Re: Small block racers, need help with cam choice [Re: gregsdart] #3082390
10/01/22 10:47 PM
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You can talk to some friends, but that doesn't mean that they will listen, just like our kids whistling grin
Larger C.I. make more power when everything else in the motor is designed to make more power on a bigger C.I. motor shruggy
I've never worked on or know anyone I would trust on reliable feedback that had more than a 4.0-inch SB Mopar stroker motor, pump gas or race gas shruggy


Mr.Cab Racing and winning with Mopars since 1964. (Old F--t, Huh)
Re: Small block racers, need help with cam choice [Re: gregsdart] #3082394
10/01/22 11:05 PM
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hi
have you tryed timing it to 34 deg ?

with compression that low more timing may help ?

carb may need to be adj for the 34 deg to get proper afr .

Re: Small block racers, need help with cam choice [Re: calrobb2000] #3082424
10/02/22 08:33 AM
10/02/22 08:33 AM
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Originally Posted by calrobb2000

hi
have you tryed timing it to 34 deg ?

with compression that low more timing may help ?

carb may need to be adj for the 34 deg to get proper afr .






Car was chassis dyno'd.
I hope my friend considers the stroker idea. It should turn it into a much superior setup all around.


8.77 153 mph best, 3055 lbs 528 indy 440-1 alky
Re: Small block racers, need help with cam choice [Re: Cab_Burge] #3083723
10/06/22 06:56 AM
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Originally Posted by Cab_Burge
You can talk to some friends, but that doesn't mean that they will listen, just like our kids whistling grin
Larger C.I. make more power when everything else in the motor is designed to make more power on a bigger C.I. motor shruggy
I've never worked on or know anyone I would trust on reliable feedback that had more than a 4.0-inch SB Mopar stroker motor, pump gas or race gas shruggy

Since his bolt ons, ( top end) are all moderate performance parts, airgap intake, etc, I figure the long stroke won't be an issue with block strength, using an rpm range of 6000 or less . His ideal end result is hi torque, somewhat street able, reliable 11:50 car. With N average DA of 2000+, and a tight converter, a motor that may run as quick as 11.25 with great DA and perfect converter might just hit the nail on the head , and run that 11:50 limit (no rollbar) yet be able to go ten miles to the cruise in events in style, and reliability.


8.77 153 mph best, 3055 lbs 528 indy 440-1 alky
Re: Small block racers, need help with cam choice [Re: fast68plymouth] #3083725
10/06/22 06:59 AM
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Originally Posted by fast68plymouth
If the car is being raced with closed exhaust, carefully consider how much overlap you really want.

Imo, a 260@.050 cam for an 8.5:1 360 will want a pretty loose 8” converter and enough gear to turn 6500+ thru the traps.

Dwayne, do you think if that motor got up to 10/1 with that cam, at 408 cubes or more, it would work well at a little less rpm, like max 6000 to 6200?


8.77 153 mph best, 3055 lbs 528 indy 440-1 alky
Re: Small block racers, need help with cam choice [Re: gregsdart] #3083756
10/06/22 08:59 AM
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A 260/264-106 cam is just not what I’d do for a street/strip car with a tight converter, that will be driven around(and possibly raced) with closed exhaust.

I wouldn’t get too hung up on trying to find a “shelf cam” to use, since it’s unlikely anything suitable will actually be on the shelf.


68 Satellite, 383 with stock 906’s, 3550lbs, 11.18@123
Dealer for Comp Cams/Indy Heads
Re: Small block racers, need help with cam choice [Re: fast68plymouth] #3083759
10/06/22 09:10 AM
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Originally Posted by fast68plymouth
A 260/264-106 cam is just not what I’d do for a street/strip car with a tight converter, that will be driven around(and possibly raced) with closed exhaust.

I wouldn’t get too hung up on trying to find a “shelf cam” to use, since it’s unlikely anything suitable will actually be on the shelf.



That is exactly what I do with that very cam. Drive the car everywhere, with tight 4900-5000 flash vert. Used this cam with 10 to 1 360, and now with my stroker. And I run shootout type( kooks) mufflers on it.
Seems to work OK to me.
Car doesn’t “ get over the hump” with the cam until about 2800 rpm or so. Cruises nice about 3200 rpm

Edit…see it has 3800 vert..needs more

Last edited by B3422W5; 10/06/22 09:13 AM.

69 Dart GTS A4 Silver All steel, flat factory hood, 3350 race weight
418 BPE factory replacement headed stroker
Best so far, 10.68 at 124.48
1.44 best 60 foot.
6.76 at 101.63 best 1 /8

Re: Small block racers, need help with cam choice [Re: gregsdart] #3083780
10/06/22 10:48 AM
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Originally Posted by gregsdart
Originally Posted by Cab_Burge
You can talk to some friends, but that doesn't mean that they will listen, just like our kids whistling grin
Larger C.I. make more power when everything else in the motor is designed to make more power on a bigger C.I. motor shruggy
I've never worked on or know anyone I would trust on reliable feedback that had more than a 4.0-inch SB Mopar stroker motor, pump gas or race gas shruggy

Since his bolt ons, ( top end) are all moderate performance parts, airgap intake, etc, I figure the long stroke won't be an issue with block strength, using an rpm range of 6000 or less . His ideal end result is hi torque, somewhat street able, reliable 11:50 car. With N average DA of 2000+, and a tight converter, a motor that may run as quick as 11.25 with great DA and perfect converter might just hit the nail on the head , and run that 11:50 limit (no rollbar) yet be able to go ten miles to the cruise in events in style, and reliability.


He dosent have enough cylinder head to hurt that block. 4.125 crank Molnar or K1 with Chevy pin, 6.200 rod, wrist pin still wont be into the rings as long as he still has a 9.56 or greater deck height. Torquey under 6500rpm combo that should hit his goals with the right convertor and cam.

Re: Small block racers, need help with cam choice [Re: usp4u] #3083827
10/06/22 12:31 PM
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Originally Posted by usp4u
Originally Posted by gregsdart
Originally Posted by Cab_Burge
You can talk to some friends, but that doesn't mean that they will listen, just like our kids whistling grin
Larger C.I. make more power when everything else in the motor is designed to make more power on a bigger C.I. motor shruggy
I've never worked on or know anyone I would trust on reliable feedback that had more than a 4.0-inch SB Mopar stroker motor, pump gas or race gas shruggy

Since his bolt ons, ( top end) are all moderate performance parts, airgap intake, etc, I figure the long stroke won't be an issue with block strength, using an rpm range of 6000 or less . His ideal end result is hi torque, somewhat street able, reliable 11:50 car. With N average DA of 2000+, and a tight converter, a motor that may run as quick as 11.25 with great DA and perfect converter might just hit the nail on the head , and run that 11:50 limit (no rollbar) yet be able to go ten miles to the cruise in events in style, and reliability.


He dosent have enough cylinder head to hurt that block. 4.125 crank Molnar or K1 with Chevy pin, 6.200 rod, wrist pin still wont be into the rings as long as he still has a 9.56 or greater deck height. Torquey under 6500rpm combo that should hit his goals with the right convertor and cam.



Frankly, not any use for anything over 4 inch stroke with anything but more “ exotic” head. Even 4 inch is frankly overkill for stock replacement type heads.
This allows more commonly available crank/ Rod/ piston kits than 4.15 or 4 .25….plus less piston wear/rock.


69 Dart GTS A4 Silver All steel, flat factory hood, 3350 race weight
418 BPE factory replacement headed stroker
Best so far, 10.68 at 124.48
1.44 best 60 foot.
6.76 at 101.63 best 1 /8

Re: Small block racers, need help with cam choice [Re: B3422W5] #3083831
10/06/22 12:45 PM
10/06/22 12:45 PM
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I don't have the card with me , but Bullett ground me a HFT stick with .545 lift and 236 ish duration @ .050 that made 492 & 492 , 106 cl , all in at 6k. in a small head 408. ( gasket matched & bowl work Speedmasters )
Haven't had it in the car yet , but it didn't care for anything but 34 degrees total on the pump. 2 degrees timing either way dropped off.







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