Camshaft selection 383 tunnel ram

[Remusa12]

People seem to misunderstand everything I'm saying
Somewhat cheap refers to the fact I'm buying parts that are good but not necessarily brand new or from a store. The brand new rods I bought were half price because the guy bought the wrong ones for his. The "swap meet heads" I don't understand the hangup if I buy a set of edelbrock performers from the swap meet for much less than they sell new that's a benefit, I'm not buying unrebuilt iron heads and slapping them on without going to a machine shop, my dad's 383 that lived at 7200 for many runs and is still in the car in a milder version now not needing rebuilt coat $3500 to build in 1980 with polished rods and a built bottom end. My other friends 383 in his 71 charger would launch at 7800 rpm to do a wheelie he did this all day for several days and only stopped because he broke the case on the transmission. All of this was with hydraulic cams people seem to think high rpm motors didn't exist or live before roller cams where readily available don't understand about what I'm doing.

 

[Sweet5ltr]

We made 445 hp and around 430 Ft/Lbs on the Dyno out of a .030" 383 about 10 years ago ? Pump Gas just using a XE274H Hydraulic F.T. Cam, Ported Iron Heads W/Adjustable Rockers and a Torker Intake/750 cfm.....
but we never need to spin it anywhere near 7,000 rpm to do so ?
from memory..... I don't think we even exceeded 6000 rpm ? but I would have to go dig up the Dyno sheet to know for sure ?

As always...
I think the best way to approach this is to just slow down.... come up with a hp target ? then go from there ?
PLENTY of smart cookies in here that I believe can come up with a reasonable way to attain your goals without wing'in the NUTS off your wee-83 and breaking parts ?
IMO....just say'in....
you don't need anywhere near 8,000 rpm for 500 hp out of a wee-83 !

Look at the Engine Masters 383 build by Steve Dulcich. Factory 906 heads, Performer RPM dual-plane, 1 7/8" headers, 850 carburetor, 236* @ .050 / .540" lift camshaft. 440 HP @ 6,000 RPM & 460 ft/lbs @ 4,200 RPM. Easily another 20-30 HP to be had with a Tunnel-Ram.

 

[Remusa12]

I'm not doing 8000 rpm for the horsepower goal I'm doing it because I want a high rpm motor in a car to have fun with doing something clearly no else has tried before.

 

[wagonman]

Comp CRB XE282S-10 Got it in a 470 with TF 240s. Runs like a Lady around town and a Whore when you put your foot in Her ***. Might be a bit large for a 383 but will RPM for sure.

 

[gkent]

I think the general consensus is that what you're trying to achieve is unrealistic. Personally I can't see spinning a big block past 7500 even with the best of parts. 6500 is much more realistic and in a 3000# car will likely live a decent life. My personal advise is use a BIG oil pan and a standard volume pump. At high RPM pressure will not be the issue but volume will be. You want to move the oil slow enough that it doesn't drain the pan. That was my (costly) problem. 500 HP is easily achievable but go with a 400 block - larger bore and a bit beafier around the mains. A 440Source bottom end would be decent and relatively inexpensive.

 

[Remusa12]

Look at the Engine Masters build by Steve Dulcich. Factory 906 heads, Performer RPM dual-plane, 1 7/8" headers, 850 carburetor, 236* @ .050 / .540" lift camshaft. 440 HP @ 6,000 RPM & 460 ft/lbs @ 4,200 RPM. Easily another 20-30 HP to be had with a Tunnel-Ram.

Tunnel rams are a larger benefit than even 20 its considered a 50hp boost usually but I've seen many engines live at 75-8000, thank you though sweet for seeing it.

 

[JackpotJim]

Honestly, If you are building a B motor to go fast on a budget at 10 to 1 compression why not build it for nitrous. I'd forget about trying to make it hold together at 8000 rpm and build the bottom end for a 250 shot plate system with good heads and a solid flat tappet cam you can go fast. Call a couple cam company and see what they recommend for a nitrous cam. Only you will see if the tach goes to 8000 RPM.

 

[Sweet5ltr]

I'm not doing 8000 rpm for the horsepower goal I'm doing it because I want a high rpm motor in a car to have fun with doing something clearly no else has tried before.

Many have tried I'm sure, those blocks were deposited in the junkyard shortly after. Talking about what shade-tree drag racers were doing in 1980 to even the mid-1990's is irreverent to us today - factory [B & RB] long blocks were pennies on the dollar back then, everyone could afford to experiment.

 

[beanhead]

I'm not doing 8000 rpm for the horsepower goal I'm doing it because I want a high rpm motor...

That statement speaks volumes... I think your best bet at this point is to go talk to your buddy that launched his hydraulic cammed 383 at 7800 and copy his build exactly.

 

[Remusa12]

I paid $200 bucks for the whole engine, my friend did it without the tunnel ram and a manual in a full body car, mines a small car thats probably less than 2500 pounds with a driver.

 

[Sweet5ltr]

That statement speaks volumes... I think your best bet at this point is to go talk to your buddy that launched his hydraulic cammed 383 at 7800 and copy his build exactly.

Very good advice here, if your friend was launching @ 7,800 with a low-deck, he would be my first resource.

 

[beanhead]

The A-body brothers have been discussing a similar idea over on their side, it's an interesting read. Just keep in mind, we hope you're successful! Some of the guys commenting here and on the other site have many years of building and/or racing experience (some of them even get to do it for a living!)
https://www.forabodiesonly.com/mopar/threads/8k-rpm.449323/

 

[mopar 3 B]

Not saying it can't be done. Just not for cheap. You can polish stock rods all you want at 8000 its not going to hold together. Opening up the oiling will be the death of it at that rpm. The bearings and lifters dont need it so whats the purpose?

 

[matthon]

I'm not well versed in engines, cams, etc., but I have been running a 383 with a tunnel ram, and a mix of new and second hand parts, for years.

Upgraded to efi, and a taller tire, went back to the shop and now saving for a different cam, valvetrain, and gears.

I never get close to 8k, but I'm definitely interested in where this thread ends up.

 

[dadsbee]

Scattered I'd think Matthon....

 

[Hemirunner]

Interesting build. I’m not sure what your budget is, but I say go for it. A couple of observations...
1) use a 400 block, the bigger bore is free power and would let you run an aftermarket aluminum head with less valve shrouding issues.
2) The pistons you’ve chosen are heavy. If your budget can swing some lighter ones (with a better ring package) that would be the way to go to keep the rods in the block.
3) definitely a solid flat tappet cam
Good luck with it and keep us posted!

 

[Hemirunner]

The A-body brothers have been discussing a similar idea over on their side, it's an interesting read. Just keep in mind, we hope you're successful! Some of the guys commenting here and on the other site have many years of building and/or racing experience (some of them even get to do it for a living!)
https://www.forabodiesonly.com/mopar/threads/8k-rpm.449323/

I read through that. The negativity is amazing. We did an 8000rpm small block a decade ago. I used a stock crank and edm mod motor rods that oiled pins through the beam mainly because they fit the length requirements for the pistons I chose. It was a 3.31 stroke. Shouldn’t be that big a deal with a 3.38 in a low deck block.

 

[BSB67]

Yah.

The 8000 is probably a bit hopeful, and the whole piston/compression/cam/valve will be an issue to sort out. But don't see it as that crazy.

Here is what I do know. My 383 in my GTS today will go 7000 rpm with a hydraulic cam. It gets there pretty fast, but when its there it hits a wall. This same 383 use to have a Crower solid flat tappet, 256° @ 0.050". That cam I actually shifted at 7000 rpm, would go 7500, and bounced it off the 8000 rpm tach probably 20 times (its a 4 spd car). This motor has TRW slugs and factory rods.

That said, peak power is/was probably at 6000 and 6500 for the hyd and SFT respectively. But is simply just amazing how this motor pulls past peak. And I'm not saying its a rational thing to do. But I will say this; I've had 440s, 500s and been in a bunch of other cars that make way more hp and way faster than this little 383, but none are more fun to drive.

To the OP, FWIW, my pistons probably have 0.20 to 0.25" valve pockets and had to advance the cam to get the minimum exhaust valve to piston clearance.

 

[Remusa12]

I've been recommended in other threads that a tunnel ram works best with a 230 @ 0.050 duration but I looked at Howard's cam number 720152-08
288/292 duration .616/.620 lift, range is listed at 34-7400

 

[BSB67]

I've been recommended in other threads that a tunnel ram works best with a 230 @ 0.050 duration but I looked at Howard's cam number 720152-08
288/292 duration .616/.620 lift, range is listed at 34-7400

That Howard's cam is very similar to the Crower cam I referenced above.