IM surprised by Richard Holdeners 360 Magnum camshaft swap.......

-
Brooks James

Brooks James

VET, CPT, Huey Medevac Pilot
FABO Gold Member
Joined
Dec 12, 2020
Messages
4,878
Reaction score
3,193
Location
Fruitland Park Fl
Im 65 and have been around cars for 50 yrs. I have never seen a mild engine gain 60 horse power with a change to a relatively light camshaft !
 
Brooks James said:
Im 65 and have been around cars for 50 yrs. I have never seen a mild engine gain 60 horse power with a change to a relatively light camshaft !
Click to expand...
Why wouldn't it?

How I see low hp engines, have what I call free hp, what the long block can make with just a 4bbl cam and headers, basically what's possible with the stock heads and cr. We know magnum heads and cr are able to make at least 400 hp which is a 100 hp over what a stock cammed magnum with 4bbl and headers which is about 20 hp over stock intake and exhaust.

The cam he uses is about half of what a 400 hp magnum uses, plus stock cam are so weak doesn't take much to be a big improvement. Even stock duration on a tighter lsa with more lift, probably be a decent improvement.
 
Last edited:
Or say the other way around, if you took a 650 hp 408 and replaced its say 260 @ 0.050" cam with a stock 318 cam you wouldn't expect to lose over a hundred hp probably a couple plus hundred hp ?
 
Well, there is also the MP crate engine to also throw out in the mix which is a stock long block, add in the cam, intake, 750 cfm carb and 1.3/4 headers, which are smaller than what Richard used @ 1-7/8, and the MP offering made 380hp as listed by MP but has been routinely seen on a dyno @ 400hp or better.

Considering that MP Hyd. roller cam was missing compression and a decent head to work well, it did well and still is considered a small cam.
 
Factory cams are so ridiculously small, you can make a decent upgrade and add good power from the very bottom and gain a few hundred usable RPM up top. cam specs from my 97 5.9 magnum were 250/264 duration w/ 398/401 lift - similar to early LA 318 cams.
 
Last edited:
horsepowrinc said:
Factory cams are so ridiculously small, you can make a decent upgrade and add good power from the very bottom and gain a few hundred usable RPM up top. cam specs from my 97 5.9 magnum were 250/264 duration w/ 398/401 lift - similar to early LA 318 cams.
Click to expand...
No doubt! In addition…. Cam size dependent, little to no loss of low end torque worth mentioning. Address the cylinder heads for better power no matter the cam size.
Newbomb Turk said:
He’s using a set of 1 7/8 headers on that engine. I’m betting if he says anything he says they are 1 3/4. They are not.
Click to expand...
He never mentions header size IIRC. He would get called out instantly by you and I right quick. I have 2 sets of those. IMO, a bit big for the test on hand. But, ya use what ya got.
 
I believe he could tune that high rpm lean spot out by changing out the emulsion tube.
 
rumblefish360 said:
Well, there is also the MP crate engine to also throw out in the mix which is a stock long block, add in the cam, intake, 750 cfm carb and 1.3/4 headers, which are smi done aller than what Richard used @ 1-7/8, and the MP offering made 380hp as listed by MP but has been routinely seen on a dyno @ 400hp or better.

Considering that MP Hyd. roller cam was missing compression and a decent head to work well, it did well and still is considered to be a small camshaft
Click to expand...
 
Last edited:
I was under the impression the 5.2 and 5.9 Magnum roller cams were a bit hotter than the LA roller cam, which did, in fact look pretty near identical to the FT pre- LA roller cam.

I've asked in a few places if the LA roller version at least had faster ramps to take advantage of the rollers, but never got a definitive answer.

This info is not super easy to find.

This is what I have:

318 2 barrel 67 Hydraulic 390/390 244/244
318 2 barrel through 88 Hydraulic 373/400 240/248
318 4 barrel Hydraulic 430/444 268/276
318 roller cam Hydraulic 391/391 240/240

360 2 barrel 71-74 Hydraulic 410/412 252/256
360 2bb 75-up Hydraulic 410/410 252/252
360 4 barrel Hydraulic 430/444 268/276

5.2 Magnum Hydraulic Roller 432/432 251/264 113CL *-looky there, it IS smaller than some previous.
5.9 Magnum Hydraulic Roller 410/417 249/269 109CL
 
YY1 said:
I was under the impression the 5.2 and 5.9 Magnum roller cams were a bit hotter than the LA roller cam, which did, in fact look pretty near identical to the FT pre- LA roller cam.

I've asked in a few places if the LA roller version at least had faster ramps to take advantage of the rollers, but never got a definitive answer.

This info is not super easy to find.

This is what I have:

318 2 barrel 67 Hydraulic 390/390 244/244
318 2 barrel through 88 Hydraulic 373/400 240/248
318 4 barrel Hydraulic 430/444 268/276
318 roller cam Hydraulic 391/391 240/240

360 2 barrel 71-74 Hydraulic 410/412 252/256
360 2bb 75-up Hydraulic 410/410 252/252
360 4 barrel Hydraulic 430/444 268/276

5.2 Magnum Hydraulic Roller 432/432 251/264 113CL *-looky there, it IS smaller than some previous.
5.9 Magnum Hydraulic Roller 410/417 249/269 109CL
Click to expand...
No 318 ever came with a 340 cam and very few 360 did, most 4bbl 360 had 2bbl cams.
 
rumblefish360 said:
A quote with no reply?
Click to expand...
Senior moment forgot what to say, lol
Ahh... remembered,
It's my understanding that the vacuum at idle withe the 292 /510 camshaft in the 380 hp crate motor doesn't provide enough to use most power brake set up
 
Last edited:
Info for non-HP engines is not easy to find and not easy to verify, especially the LA roller and early 1980's stuff.

Some info for Magnum (roller small block) engines is not super easy to find or verify either.
 
YY1 said:
I was under the impression the 5.2 and 5.9 Magnum roller cams were a bit hotter than the LA roller cam, which did, in fact look pretty near identical to the FT pre- LA roller cam.

I've asked in a few places if the LA roller version at least had faster ramps to take advantage of the rollers, but never got a definitive answer.

This info is not super easy to find.

This is what I have:

318 2 barrel 67 Hydraulic 390/390 244/244
318 2 barrel through 88 Hydraulic 373/400 240/248
318 4 barrel Hydraulic 430/444 268/276
318 roller cam Hydraulic 391/391 240/240

360 2 barrel 71-74 Hydraulic 410/412 252/256
360 2bb 75-up Hydraulic 410/410 252/252
360 4 barrel Hydraulic 430/444 268/276

5.2 Magnum Hydraulic Roller 432/432 251/264 113CL *-looky there, it IS smaller than some previous.
5.9 Magnum Hydraulic Roller 410/417 249/269 109CL
Click to expand...

Here are the numbers I got from having a 2000 Ram 5.9 cam run through the Cam Doctor at Bullet Cams:

Duration @ 0.050: I/E 189*/194*
Lobe separation angle: 111*
Lift @ cam: I/E 0.273"/0.278"
Valve lift w/ 1.6 rockers: I/E 0.437”/0.445”
 
DionR said:
Here are the numbers I got from having a 2000 Ram 5.9 cam run through the Cam Doctor at Bullet Cams:

Duration @ 0.050: I/E 189*/194*
Lobe separation angle: 111*
Lift @ cam: I/E 0.273"/0.278"
Valve lift w/ 1.6 rockers: I/E 0.437”/0.445”
Click to expand...
wow, isnt that close to the 68-71 4 speed 340 camshaft ???, excepct the lsa is 111 IIRC the 340 was 113-114
 
Efficiency?

..and coupled with roller ramps could equal same power?
 
You must log in or register to reply here.
-

Back
Top