[ponchjoe]

Ok, my turn....
I'm seeking input for both a Hyd flat tapper and Hyd roller cam for this set up:
68 GTO, .030 455, 6.662 Eagle H beams, stock crank and Icon 888 Pistons. The head choices are 5c-4 or 96s stock, assume 9.5 to 9.75:1. The car is an M20 4spd with 3.23 gears. Intake will be a stock manifold and reworked Qjet. If necessary, I'll go to an RPM. The exhaust will be either RA manifolds or headers through 2.5 H pipe and tails.
The car will be a street/Hwy driven car with working AC. For the HFT, I am considering the Crower 60919 and Rhoads. I know I've added some variables here but any input is appreciated.

Thanks guys!

[b-man]

If going flat-tappet I'd say Crower 60243, no Rhoads lifters: http://www.crower.com/camshafts/pont...m-284-hdp.html

Keep the stock intake.

I'd use the RA/HO exhaust manifolds.

[ponchjoe]

Thanks Bman. I have used the 60243 in a similar application. It was pretty mild but ran good. Thought I would try something different.

[b-man]

Hard to go wrong with the Stump Puller hyd roller from SD.

Pretty 'generic' recommendation, but it works well for a lot of users especially those using the RA/HO manifolds.

[HWYSTR455]

Sounds like a perfect candidate for a XR288HR, think lack of headers will limit you to a lower RPM range. Heads will also limit RPM unless they've been worked.

http://www.compcams.com/Company/CC/c...csid=1217&sb=2

If you go much bigger, gears will play a part too.

I like the 60243 Crower, with manifolds it's a good choice for your setup. Much bigger and you need more static CR.

EDIT: You can also spray the 60243 if you choose.

.

[steve25]

The 2.5" head pipes are going to be a pretty good cork to revs much above 5500 with the 455 so make your cam pick tempered by that fact.

[ponyakr]

I'll be the odd man out again and go with a RA4 grind like the Crower 60919 or Melling SPC-8, with Rhoads lifters. This is a well proven combo which will idle smooth, make plenty of vac, have 500ft lbs of torque at just over 3000rpm and will pull strong to 5000rpm. That's tire smokin power for a street ride, and makes it's power in the range that street cars run most of the time. We won LOTS of races with this combo, leaving from an idle and shifting at 5000.

It's also MUCH cheaper than a roller set-up. But if you got the $ to spend, there's no reason not to go with a roller. I think everybody can agree that a roller is better for several reasons and will make more power. If you go roller, I agree that one of the SD Cams would be hard to beat. They are both well proven, with dyno results and testimonies.

http://www.sdperformance.com/viewPro...productID=1815

http://www.sdperformance.com/viewPro...productID=1816

[ponchjoe]

Are 1 5/8 headers any better than RA manifolds?
I'm thinking of a gasket match and bowl clean up on the heads. Which are better, the 5cs or the 96s?
Thanks guys

[b-man]

Originally Posted by ponchjoe

Are 1 5/8 headers any better than RA manifolds?
I'm thinking of a gasket match and bowl clean up on the heads. Which are better, the 5cs or the 96s?
Thanks guys

The 1-5/8" headers are better. I recall that Floyd Hand ran into the mid-11s with a set on his 455 '67 LeMans, a bigger primary tube size didn't pick up anything on his combo.

Go with the 5C heads, better intake port but need a little more work on the exhaust side compared to the #96 heads. Even if you don't touch the ports I'd say go with the 5C heads, converted to the 1.77" exhaust valve.

I agree the RAIV cam would also be a good choice, just not a big fan of the noisy Rhoads lifters.

[rexs73gto]

ponchojoe. I run almost the same combo, with the difference of I run the SRP forged pistons. I have a 73 455 +30, eagle H-beam rods a RAIV cam with a Performer RPM intake with the alum. E-heads. I run a tricked Q-jet. A 79 301 Q-jet. Its in a 73 GTO wieghing right at 3850 with me in it. I have the round port RA exhaust manifolds with full exhaust to the rear axle right now. Also the rear is a set of Zoom 3:73 rear gears. I run an M-22 Muncie Trans. I have the Pertronix ign. The car runs 11:70's & 12:30's with street tire. I know I have the E-heads which IMO made a big difference when I installed them. They are completely stock, I didn't go with the upgrade of the 1:77 exhaust valves which I may in the future. The car idles at about 850-900 as my tack & dwell ins't the best. But I have very good street manners & will set you back in the seat right of idle. I like the RAIV cam & have used it in both 400's & 455's & I do think they are better suited for the bigger cube engines. The cam I use is the Crane Blue print RAIV cam. I've used it in my last 4 engines & really like them.

[steve25]

Your E heads on your motor throw out the apples to apples comparo by a long shot there Rex!
Also I would sooner run a set of new cast improved exh manifolds over 1 5/8" headers!

[ponchjoe]

Steve,
I took Rex's input at face value. I am leaning towards the 60919 or 60243 but would love to hear about Bullet, Lunati and Comp input.

Joe

[ponyakr]

Originally Posted by ponchjoe

Which are better, the 5cs or the 96s?
Thanks guys

Another reason to go with the 5c is that they have hardened seats for use with unleaded gas. I've read that they are basically identical to the 6x--can't confirm.

[ponyakr]

Originally Posted by ponchjoe

Steve,
I took Rex's input at face value. I am leaning towards the 60919 or 60243 but would love to hear about Bullet, Lunati and Comp input.

Joe

The 60243 looks similar to the 60919 but with a steeper ramp.

Bullet and others will grind just about any lobes you want.

http://www.bulletcams.com/Masters/Hlobes.htm

This Lunati has about 10 degrees less dur @ .050 than the RA4 grinds.

https://www.lunatipower.com/Product....d=4285&gid=280

Then if you wanna go with a steep ramp there is this Voodoo 276 or the CC XE 274.

https://www.lunatipower.com/Product....d=1777&gid=287

The biggest CC I've used was a 244/253 @ .050, with Rhoads lifters. It still had a decent idle below 1000rpm. Best ET was a 9.85 @ 104 mph on a 1000ft track. But a cam this big needs lots of compression. The motor was a 455 with 72cc D-ports. It looks like CC still makes a 244 and a 253 in single patterns, but they can probably grind a dual pattern if you'd like one.

http://www.compcams.com/Company/CC/c...csid=1198&sb=2

http://www.compcams.com/Company/CC/c...csid=1199&sb=2

[ponyakr]

Here's a few of the lobes CC can grind.

MAGNUM HYDRAULICS
Magnum Hydraulics are to be used in high performance applications with a minimum tappet diameter of .842" (Chev- rolet) or larger. These lobes are more aggressive in their design characteristics and can be used as intake or exhaust
lobes. They are a big brother to the High Energy™ family and are frequently used by the budget minded Saturday Night
racer. They also provide a very "throaty" sound.

Rated Duration @
.006" Tappet Lift
.842" Min. Dia.

5201 270-4 224 .470 .501
5202 270-5 224 .450 .480
5239 276-3 228 .474 .506
5213 276-4 226 .464 .494
5216 280-3 230 .459 .490
5203 280-4 230 .480 .512
5240 280-9 232 .483 .515
5241 284-3 236 .474 .506
5208 286-3 236 .491 .523
5229 288-9 237 .483 .515
5214 292-2 244 .501 .534
5204 292-3 244 .485 .518
5209 296-3 246 .510 .544
5210 305-3 253 .525 .560
5217 305-4 253 .507 .541

[gtofreek]

Originally Posted by ponyakr

Another reason to go with the 5c is that they have hardened seats for use with unleaded gas. I've read that they are basically identical to the 6x--can't confirm.

Check them good for cracks. They crack easy, like the 4X head.

[rexs73gto]

I know my comparision with the e-heads are a bit off & a little bit on the high side of apples to apples but I was just giving what I was getting with my set up which was with the E-heads. I know the E-heads give it a bit of an unfair boost but all the other parts were close which if you did go up to the E-heads what it would be like. Before I ran the E-heads I ran a set of #48 RAIII on that set up. I like the E-heads better. The # 48's seemed to work better for me when i had them on the 400 +.60 over. with the RAIV cam.

[Tim Corcoran]

If your compression is 9.75:1 then your knocking on the detonation door. If you run the HO/RA manifolds then you should have a cam with a short overlap to improve exhaust scavenging but enough duration so you don't build too much dynamic compression. With HO/RA manifolds and a full 2-1/2 inch exhaust I would recommend a Lunati Voodoo 10510703 but would have it ground on a 112 LSA.

[gtofreek]

Originally Posted by Tim Corcoran

If your compression is 9.75:1 then your knocking on the detonation door. If you run the HO/RA manifolds then you should have a cam with a short overlap to improve exhaust scavenging but enough duration so you don't build too much dynamic compression. With HO/RA manifolds and a full 2-1/2 inch exhaust I would recommend a Lunati Voodoo 10510703 but would have it ground on a 112 LSA.

Good cam, but I would go one step bigger with the 10510704, ground on a 112° LSA. The 703 is still pushing it with 9.75:1. I've used the 704 in several 455's and it runs great in them.

[ponyakr]

I'm obviously no cam expert. But I can read. The steep ramp cams such as the Voodoo and XE series are designed to increase cylinder pressure. So, if you already have 9.75 CR, a steep ramp would only make the problem worse. This is assuming pump gas of sometimes questionable quality. But hey, if you run racing gas, pump it on up !

It has been said by many that a cam with more advertised dur will actually bleed off some of this cylinder pressure at lower rpm, which is supposed to help prevent detonation. (I'm assuming he is shooting for a SAFE engine rather than absolute max power.)

So does this not hold true for this 9.75 CR engine for some reason ?