Solid roller cam question

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HuntedDuckV351

HuntedDuckV351

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So I'm putting another race motor together and needed some help on cam selection....Cars weights 3200 with me in it powerglide 1.80 gearset. 5.00 rear gear. Will have the bloomer heads with a victor 340 intake running on E85. I plan on going with 1.6 rockers. I thinking something in the .440 lobe 270 274 @50 on a 108 LSA.
 
Oh if I leave the heads at 70cc with my pistons 0 deck the compression will be 12.6:1
 
I would call Schneider Cams. They've got a great reputation.
 
A few more things a cam supplier will likely want to know…..

-engine displacement
-stall speed
-tire size
-header size
-desired max rpm
-1/8 or 1/4 mile
 
PRH said:
A few more things a cam supplier will likely want to know…..

-engine displacement
-stall speed
-tire size
-header size
-desired max rpm
-1/8 or 1/4 mile
Click to expand...
Yep sorry....408, convertor flashes 6100 but I'm gonna bring that down to 5900....14x32 tires 1 7/8headers and 1/8th mile....
 
Bore
Stroke
Rod length
RPM at peak torque
RPM at peak power

And if you have an idea of what you want for effective compression ratio. If not I’ll pick what I think it should be for E85.


I’ll run some numbers tonight when I get home.
 
Another consideration will be what spring package will those heads accommodate?

No point selecting a cam that uses springs that won’t fit on the heads.

Sounds like a running combo.
What heads are you running now?

Is this a head change or just a cam swap?
 
I have had good results and customer experience specifying and ordering a custom cam grind with Howard's.
 
Newbomb Turk said:
Bore
Stroke
Rod length
RPM at peak torque
RPM at peak power

And if you have an idea of what you want for effective compression ratio. If not I’ll pick what I think it should be for E85.


I’ll run some numbers tonight when I get home.
Click to expand...
4.040
4.00
6.123
5000 guessing
6500 guessing

Thank you for the help
 
PRH said:
Another consideration will be what spring package will those heads accommodate?

No point selecting a cam that uses springs that won’t fit on the heads.

Sounds like a running combo.
What heads are you running now?

Is this a head change or just a cam swap?
Click to expand...
Gonna run the 1238x pac springs with these heads...hoping to run 6.20s in the 1/8th
Have a set of Ryan J from shady Dell.
Gonna be a complete new motor

20220501_140227.jpg
 
Vertex_Jeff said:
I have had good results and customer experience specifying and ordering a custom cam grind with Howard's.
Click to expand...
That's another great choice. I like how they give their grinds a lot of lift per duration. Just like a Chrysler needs.
 
I do have this cam already....
Click to expand...

Imo, too big for the desired “under 7000” rpm limit.

It’s also a little odd with the exhaust lobe being a faster design than the intake.
 
When getting into the 400+ lobe lift range, I doubt anybody has a greater range to choose from than Comp. Chris Ryan at Comp can help you out & is very reliable.
 
Here's what I'd use. This is based on 12.6:1 compression and an effective compression ratio of 10.5:1, plus the other numbers you posted. And its also based on peak torque at 5000 and peak power at 6500.

303/271 .666
319/287 .661
110/107

That's for 1.6 rockers. If I had the choice I'd run 1.5's on the exhaust side so that's .620 lift and it would slow things down a bit.

Those are Howard's standard ramp mechanical roller lobes. So they are going to less aggressive than I could have used.
 
HuntedDuckV351 said:
Oh if I leave the heads at 70cc with my pistons 0 deck the compression will be 12.6:1
Click to expand...

Assuming you are running zero deck flattops ( like I am) you will be nowhere near 12.6 compression.
I had Rod mill my heads to 61cc specifically to get my compression up around 12.3-12.4. At 70cc it would be under 11.5.
Regards cam, know a couple guys running the Crower roller(268/274) with great success with Bloomers. Dont think there would be a need with a glide and relatively heavy car to go much if any bigger.
It’s the cam I would probably buy if I upgraded to a roller.
 
Newbomb Turk said:
Here's what I'd use. This is based on 12.6:1 compression and an effective compression ratio of 10.5:1, plus the other numbers you posted. And its also based on peak torque at 5000 and peak power at 6500.

303/271 .666
319/287 .661
110/107

That's for 1.6 rockers. If I had the choice I'd run 1.5's on the exhaust side so that's .620 lift and it would slow things down a bit.

Those are Howard's standard ramp mechanical roller lobes. So they are going to less aggressive than I could have used.
Click to expand...
Thank you very much for the info....I will look at there stuff.
 
B3422w5 said:
Assuming you are running zero deck flattops ( like I am) you will be nowhere near 12.6 compression.
I had Rod mill my heads to 61cc specifically to get my compression up around 12.3-12.4. At 70cc it would be under 11.5.
Regards cam, know a couple guys running the Crower roller(268/274) with great success with Bloomers. Dont think there would be a need with a glide and relatively heavy car to go much if any bigger.
It’s the cam I would probably buy if I upgraded to a roller.
Click to expand...
Hey Don they are Domes....the glide is great for consistency but leaves ET on the table.
 
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