tomngary

Hello all,
My local speed shop that had redone a set of #6 heads for
my 403 provided this cam for my build:
a comp cams 275DEH. In the olds dual energy line
Duration 219/233
Lift .476/.508
after market springs.
The #6 350 heads were cc'd at 66 cc. The heads have the 350 exhaust valve size and the 403 intake size. All new valves. No decking or porting. Im hoping to get around a 9.2 or so compression value.
The car now has a 3.08 rear gear and a new 2200-2400 stall converter to be installed. True 2.5 inch dual exhaust with headers. New edelbrock performer intake-non RPM.
Rejetted/rebuilt Q-jet. New DUI distributor. New timing set. New water, oil and fuel pumps. New harmonic balancer, And last but not least a set of comp cams Magnum roller tip rockers and pushrods.
I have the engine on the stand and getting ready to assemble this motor with the listed parts.
Quite a bit of money so far and I am questioning the cam choice made by the speed shop for my 403. Its a generic oldsmobile grind listed as one of 3 for the 403. Will this cam be a usable upgrade for this build? This car is not a daily driver, mostly weekend cruising and car shows. I want it to sound mean and shred tires. No drag strip use.

Thanks for any advice,
Gary

455man

Its in the right range. I'm sure our cam specialist will chime in and let ya know what his thoughts are.

oddball

Not a bad choice. I have no love for Comp, but that's just me. It'll be moderately mild. I have the Lunati 60803 in a 403. Lopey idle, but perfectly well mannered for daily driving. I'm also running edelbrock heads and flat top pistons, so don't need as much of an intake/exhaust split as an iron head build needs.

Do check out how deep the pistons sit in the bore. Some of the 403s had really tall decks, and replacement pistons don't help.

joesw31

The compcam they selected sounds fine, and should work with your combo. I have had great luck with compcams products. I would prefer that you had more rear gear, possible 3.42 or 3.23.

cutlassefi

Who might that be??

That's not a bad choice but with the more restrictive intake side vs the exhaust I'd prefer less stager. You could use more intake duration. However your gear is going to be a limiting factor no matter what.

I did a cam for a guy in Australia with a 10.0:1 403, Performer, mildly ported heads but Thorton exhaust manifolds.
It was a 224/235@.050 with .513/.523 lift if I remember right. It made 360hp at 4800 rpm and 480tq at around 3500. Great street cam.

Something with a bit less stager (maybe a 223/228@.050 or so) would give you more low to midrange torque than that Comp. That would be good for anything with less than a 3.55 rear gear.

tomngary

Thanks for all of the input, as I am still learning the corilation between all of the components and how they work together as a whole. So at this time, with all of the
parts purchased, what would be the "easiest" and mostly "cheapest" way to get the most out of the parts I have? Cam change? can you advise of any part numbers I could look at? Something more optimal for more lower rpm torque that would work with the listed parts I have.

I was kind of thinking that this cam I was provided was just "OK" but not optimal for my 403 build. Oldmobile experts are kinda rare around my area.

Thanks so much for schooling me
Gary

tomngary

Oh and like a said, something that Sounds mean and stop light tire shredding LOL

Gary

cutlassefi

Your gear will limit the amount of "mean" you can have before it becomes a pig.

I'd do something like I mentioned on a 108lsa, that would build torque early and most probably give the sound you're looking for.

tomngary

cutlassefi,
I was looking on theLunati site in the Voodoo series and I cam across this cam. Would this be more in line with my needs/usage for the 403? Or should I keep looking?


Hydraulic. Torque Monster for 400-455 c.i. daily driven street performance vehicle. Excellent torque and horsepower production with heavier emphasis on the low to mid range. Will work in ski boat applications with larger 455 c.i. engines. Choppy idle!

• Advertised Duration (Int/Exh): 262/268
• Duration @ .050 (Int/Exh): 219/227
• Gross Valve Lift (Int/Exh): .499/.510
• LSA/ICL: 112/108
• Valve Lash (Int/Exh): Hyd/Hyd
• RPM Range: 1300-5500
• Includes: Cam Kit

Part Number: 10420702LK

Thanks again for your time helping me,
Gary

tomngary

cutlassefi,
I was looking on theLunati site in the Voodoo series and I cam across this cam. Would this be more in line with my needs/usage for the 403? Or should I keep looking?


Hydraulic. Torque Monster for 400-455 c.i. daily driven street performance vehicle. Excellent torque and horsepower production with heavier emphasis on the low to mid range. Will work in ski boat applications with larger 455 c.i. engines. Choppy idle!

• Advertised Duration (Int/Exh): 262/268
• Duration @ .050 (Int/Exh): 219/227
• Gross Valve Lift (Int/Exh): .499/.510
• LSA/ICL: 112/108
• Valve Lash (Int/Exh): Hyd/Hyd
• RPM Range: 1300-5500
• Includes: Cam Kit

Part Number: 10420702LK

Thanks again for your time helping me,
Gary

joesw31

The lsa on the lunati cam is to wide, and you should consider something like what cutlassefi recommended. Cutlassefi can custom grind a cam for you and take all of the guess work out. Your limiting factor here is your rear grar.

cutlassefi

,
Thanks and I agree as stated. Tom you'll need to be careful on your cam choice because of the gear. Btw what is this going in?

Even though I'm a Lunati dealer as well, I very seldom recommend the VooDoo series of cams/lobes. They're not real easy on parts and not best suited for stock iron heads, not enough off the seat time.

I can offer you the cam grind I mentioned. I think it would work well in your combo and give you what you're looking for in spite of the gear.

tomngary

cutlassefi,
I appologize for my ignorance, I did not realize you did
custom cam grinding.

Dare I say on an Oldsmobile site that my 403 is out of my 1979 Trans Am

Can you possibly e-mail me with what you would need for a custom cam grind for my build. I would very much like to look into having you do one for me. As I have a new lifters from the comp cam kit already, I would only need the cam and springs set, correct? What kind of turn around time do you need or have? Also, this may be a stupid question from a total newbie but is it possible to grind into the cam the degree I would need without having to "degree" the cam? That is beyond my expertise.

Looking forward to hearing from you,
Gary

EliasG@woh.rr.com

captjim

The position that the cam is installed in is determined by the relationship of the cam to the crank via the chain, plus minor manufacturing tolerances. Lobe sep IS ground into the cam, but not the intake cenerline. It can be confusing, but is a crucial step to an engine performing the way that it should.
http://www.lunatipower.com/Tech/Cams...egreeACam.aspx

cutlassefi

Already emailed you, give me a shout when you're ready.

Thanks!

Jim, why didn't you send him a link to your video, you did a nice job on that.