[leeklm]

I do not intend to start another cam debate, but I have spent hours reading old threads, the jim hand book etc. and am still confused. My motor was built with the lunati 10510702 which is a 219/227 profile and 112 lsa. Motor put out 410/505 on the dyno, but virtually dies at 5k rpm. In order to extend the pwr range and give the car just a little more attitude, I am looking at a cam upgrade. This is a wknd driver with pwr brakes, so not looking at anything built for the track.

the lunati 10510703 with 227/233 and 110 lsa seems like it may get me there, but what about the RA4 grind from Comp? My engine builder thought the ra4 ramps may be a little slow, thinking there are better options. Car is a 9.4cr 455 with pocket ported 7k3 heads, RA manifolds, 4spd and 331 gears. Motor was built with good rods and pistons so can handle a little more rpm. I have both a factory and rpm intake that could be used.

What are the experienced opinions out there? I really hate to make a 3rd cam change...

Thank you!

[1971WARBIRD]

i have used and really liked the summit 2802 cam. i had one in a 73 Trans Am; 455+.030, 4X heads, 9.2 compression, performer intake, RA III exhaust manifolds, 3.08 gears.
it's specs are;224-234 @ .050 lift, .466 & .488 lift on a 114lsa. maybe use with 1.65 rockers if your heads flow well in the .500+ lift area.
if you check what Dave at SD found when they used the RA manifolds, they like a wider LSA.
cams are kind of like burgers, some people swear by Burger King, some Wendy's, and some will only eat McDonalds. if you take the time, you should be able to call Bullet Cams (Comp Cams as well) and tell them what you have and what you want out of it, and for about the same money as an off the shelf cam, they will grind you one.

[gtofreek]

We use a lot of the VooDoo cams. Very good cams. The 219/227 is pretty small for a 455. If it were me, I would use the 10510704, which is 233/241. I put the 227/233 in a 428 and it would idle down to about 550-600 without a problem. Idled good. I have also installed the 233/241 in a 428 and it idled around 800, and had about 11.5 inch's of vacuum. Idled good in gear also. Not too choppy. power brakes worked fine. It would be even mellower in a 455. This cam is about the same duration @ .050" as a RAIV, but the advertised duration is way less and it will way out power a RAIV cam and have better drivability. I would install it at 106° ICL.

[unclescratch]

Have you checked your valve springs? If they are not up to the task, they may be limiting your upper RPM. But not changing the cam won't give you 'more attitude'.

[rohrt]

That cam does look small for a 455 and that lunati 10510703 with 227/233 and 110 lsa looks like a step in the right direction. I'm not a fan tight lsa cams myself unless used with headers and I see you have RA manifolds.

I use to run a H10 110 deg lobe seperation 231 intake 239 exhaust and then went with the stump puller roller with a 114 lsa. Faster and more mild at the same time.


You never said anything about your driving habits. Jims info below may help with your decision.

http://www.pontiacstreetperformance....camselect.html

[Skip Fix]

Have Bullet grind you a Ultradyne 299/296, 231/239 on a 112 or 114. The next step bigger 296/304 with my E heads makes a streetable 525-550 HP.

Agree with the others to check your valve springs,especially if you step up the cam.

[leeklm]

Thanks for the replies so far, all good info. Regarding a couple of earlier questions, the heads flow 213/166 at .500 and the springs were checked & good. I do not recall the exact open pressure, but something like 325 lbs. Regarding driving habits, the mild cam does fit me most of the time, but when it is time to "go", I want it to GO! Like many people, I am looking for the "magic bullet".

What was attracting me to the RAIV is it seems to be a popular option for a mostly street car, and the wide LSA appears to be desired in a 455 with manifolds. I noticed it was used in a number of "recipies" in the Jim Hand book.

I think what gets confusing (including the guy at Luanti who recommended the first cam to me), is what may be considered radical in a 350 or 400, is actually somewhat mild in a 462ci motor.

So here is another question... What might be the disadvantage of using the RA4 in my combo?

[Vengeance Race Engines]

Originally Posted by leeklm

I do not intend to start another cam debate, but I have spent hours reading old threads, the jim hand book etc. and am still confused. My motor was built with the lunati 10510702 which is a 219/227 profile and 112 lsa. Motor put out 410/505 on the dyno, but virtually dies at 5k rpm. In order to extend the pwr range and give the car just a little more attitude, I am looking at a cam upgrade. This is a wknd driver with pwr brakes, so not looking at anything built for the track.

the lunati 10510703 with 227/233 and 110 lsa seems like it may get me there, but what about the RA4 grind from Comp? My engine builder thought the ra4 ramps may be a little slow, thinking there are better options. Car is a 9.4cr 455 with pocket ported 7k3 heads, RA manifolds, 4spd and 331 gears. Motor was built with good rods and pistons so can handle a little more rpm. I have both a factory and rpm intake that could be used.

What are the experienced opinions out there? I really hate to make a 3rd cam change...

Thank you!

Personally, I don't feel going to a bigger cam will do anything if your heads/intake are not up to the task. Although I do agree the cam is on the small side and will not want to make power at higher rpm, I don't think it's TOO small for the application since it is basically stock with a tiny port on it.. However, I feel it is your heads that are choking that engine and no matter what camshaft you put in it, may not give you the higher rpm scenario you are looking for. Engine is only going to make as much power as the choke point will let it, same holds true for the rpm range. Just because a bigger cam says it will go to higher rpm, doesn't mean it will. I also don't feel that engine is making power at 5,000 even though it may "go there".. Now if the heads were fully ported and a good intake/carb used, then I would say step it up because now you can take advantage of it.

[tom s]

FYI,my 455 with a stock set of 48s,9.5 CR and a comp 276 hyd roller cam,224-230 on a 110 made 432 at 5100.Stock 69 QJ,stock unmolisted 69 intake,etc.Just a pump gas 455 RA III type build.Tom

[gtofreek]

Originally Posted by leeklm

Thanks for the replies so far, all good info. Regarding a couple of earlier questions, the heads flow 213/166 at .500 and the springs were checked & good. I do not recall the exact open pressure, but something like 325 lbs. Regarding driving habits, the mild cam does fit me most of the time, but when it is time to "go", I want it to GO! Like many people, I am looking for the "magic bullet".

What was attracting me to the RAIV is it seems to be a popular option for a mostly street car, and the wide LSA appears to be desired in a 455 with manifolds. I noticed it was used in a number of "recipies" in the Jim Hand book.

I think what gets confusing (including the guy at Luanti who recommended the first cam to me), is what may be considered radical in a 350 or 400, is actually somewhat mild in a 462ci motor.

So here is another question... What might be the disadvantage of using the RA4 in my combo?

You'd be leaving a fair amount of power on the table. BTW, the lunati VooDoo cams were designed by Harold Brookshire, the same guy that designed the Ultradyne cams that Bullit sells. Ultradyne are good, but Harold used even later technology when he designed the Voodoo's and they are even better than the Ultradynes. Although Ultradyne would always be my 2'nd choice. The 233/241 Voodoo really idles pretty good in a big engine like this. Don't let the 110° lobe sep deter you either. It's fine on that cam. This cam is very explosive and makes great power in my friends 435 Pontiac with heads that breath about like yours. Idles in gear around 750 and blows the tires off and goes sideways just letting off the brake and mashing the gas. it's in a 68 GTO.

[screamingchief]

With the current choices in hydraulic flat tappet lifters,IMO expecting any hydraulic cam to "pull strongly" above 5000-5500 RPM is probably expecting a bit too much of most hydraulic lifters these days.

If you want more high RPM power,I'd look @ solid flat tappet cams.

Crower has some nice shelf SFT grinds.

My "go to" recommendation for 455 cid is usually the #60311 solid.

Very close SFT approximation to the RAIV style hydraulic cams (Crower #60919 et-al).

But the #60310 solid would work ok too,that one is more akin to the Crower #60243 hydraulic cam,which also works well in both 400 cid & 455 cid applications.

Both should easliy "out RPM" their hydraulic counterparts by a fair margin.

And then you can use the "coolface" solid lifters to help prolong the lobe life as well.

FWIW

Bret P.

[paul s.]

Originally Posted by leeklm

I do not intend to start another cam debate, but I have spent hours reading old threads, the jim hand book etc. and am still confused. My motor was built with the lunati 10510702 which is a 219/227 profile and 112 lsa. Motor put out 410/505 on the dyno, but virtually dies at 5k rpm. In order to extend the pwr range and give the car just a little more attitude, I am looking at a cam upgrade. This is a wknd driver with pwr brakes, so not looking at anything built for the track.

the lunati 10510703 with 227/233 and 110 lsa seems like it may get me there, but what about the RA4 grind from Comp? My engine builder thought the ra4 ramps may be a little slow, thinking there are better options. Car is a 9.4cr 455 with pocket ported 7k3 heads, RA manifolds, 4spd and 331 gears. Motor was built with good rods and pistons so can handle a little more rpm. I have both a factory and rpm intake that could be used.

What are the experienced opinions out there? I really hate to make a 3rd cam change...

Thank you!

Choke won't make an engine just "die" at 5k. You've got a valve spring issue.... among other possible valvetrain issues.

Where is it installed? Do you know what the intake centerline is?

I think you have enough DURATION to do what you need with the driveline set up and compression but it wouldn't surprise me if there was a better lobe out there.

[leeklm]

I did try a set of 1.65 rockers to increase duration a little and engine ran better in the 5k range, so am thinking my springs are fine, at least for this cam. I am being a little dramatic when I say engine dies at 5k, but it runs out of pwr in a hurry after 4800rpm with the 1.5 rockers. like the idea of a solid lifter but the longer durations on the crower grinds bo scare me a little. I suppose the 112 lsa will smooth things out a little...

[Cliff R]

My old engine made 455.4hp @ 5400rpm's with only 232cfm (port match and bowl work) head flow using the Crower 60919 cam. It's basically a modern copy of the 041 grind, 304/314/113LSA. The only cam I've seen mentioned so far that would really make any more power would be the larger Ultradyne Skip mentioned....IMHO

We did some back to back cam testing with my 455 after installing KRE heads with 260cfm intake ports. The same 60919 cam made 494hp @ 5600rpm's. A custom ground Comp XTQ lobed flat cam 240/248/112 made 482hp. Moving up to a 230/242/112 hydraulic roller cam made 497hp with no other changes. The big HR cam had .361" lobes, and ran a solid .12 seconds quicker at the track and over 2mph faster, showing some additional benefits of the roller design aside from what one can see on the dyno.

With the compression down at 9.4 to 1 a RAIV sized cam isn't going to be overly happy. Those cams have a lot of overlap, and really like 10 to 1 or higher compression for best results. The best choice of what's been listed will probably be the smaller 231/239 Ultradyne grind. They give up some duration and overlap of the 041 cams, but make very similar power, and a bit more user friendly with lower compression ratios........Cliff

[leeklm]

Thanks again everyone for the feedback! I learned more about cam profiles in the past couple of days, than I have in a lifetime!

Talking to Lunati, they are giving me a "deal" since I was not happy with the first cam attempt they recommended. I ordered a solid tappet 241/249- 110. Lift is .520/.540 @ 0 lash. The lunati guy compared it performance wise coming inbetween their 03 and 04 Voodoo Hyd grinds.

My engine guy is a big fan of solids, and in his words, "this will give you something to do..."

I am sure this will work out much better than the current cam, and will report back the results in the next week or two!

[Skip Fix]

Lunati had some of the UD lobes there also. Harold Brookshire worked there for a few years after closing UD, he was there when I got my 296/304 HFT in my pump gas motor.

There was a similar Lunati solid(241/249) many of my Buick GS buddies used that got them in the high 10s through mufflers.

[leeklm]

Quick update while I was out for a test drive tonight with the new cam. The Hyd cam I pulled was losing the #7 exh and #8 intake lobes! I guess my timing could not have been better to upgrade the cam. Hopefully the new one makes it more than 400 miles.

As I installed the new solid cam, stock pushrods were too short for the chevy/Pontiac style lifters Lunati provided. Ended up ordering 9.3" pushrods after spending way too much time searching for a set of speed pro's locally.

New cam works well. Definitely more attitude at idle speed. Idle vacuum coming in about 14". Seems a little borderline with my pwr brakes in the dual style small booster. engine pulls strong up past 5K and really putting out good mid-range pwr.

My only complaint is that I now get a very annoying exhaust drone with this cam at lower rpms! I already have an H-Pipe, so not sure what to try next... Maybe resonators or replace the flow masters?

[A.W.Dille]

Installing Chevy lifters in a Pontiac is not the best thing as the oil band on the Chevy lifters is not the same as the oil band on the Pontiac's. This has been an issue in the past on other boards I used to frequent to where the valve train geometry was off slightly. Crower offers the correct lifters for a Pontiac with solid cams. I think this would be a better option than the Lunati lifters.

[leeklm]

Originally Posted by A.W.Dille

Installing Chevy lifters in a Pontiac is not the best thing as the oil band on the Chevy lifters is not the same as the oil band on the Pontiac's. This has been an issue in the past on other boards I used to frequent to where the valve train geometry was off slightly. Crower offers the correct lifters for a Pontiac with solid cams. I think this would be a better option than the Lunati lifters.

thanks, I did see those from crower, but figured the others would be ok since recommended by the cam people. If I have issues, I will be wishing I spent the extra money on the crower lifters!!

[Tim Corcoran]

Never install chevy lifters in a Pontiac. I hope they work out for you. Since you were running a flat cam you won't have a good comparison between cams.