Cam question

[Ratbird]

I was wondering if anyone could tell me if this cam is very radical. I'm a newbie to building cars and not very familiar with cam numbers.
I'm trying to tune my 750 Edelbrock carb to the best possible point for our elevation which is 6800 feet. The builder of my engine (basically a 410, 390 with a 428 crank) said he didn't want to go too radical because I need to maintain enough vacuum for the power disc brakes. He's a very experienced/knowledgeable FE guy, and matched everything (heads, exhaust, intake, etc when considering my cam) Here's a link to my cam specs - http://www.lunatipower.com/Product.aspx?id=2269

One very experienced person on another site told me that this is a VERY radical cam.

thx in advance, Dave J

[Royce]

The .050 duration numbers are not that radical, In fact that would make a nice hot street cam.. the 114 lobe separation angle keeps the idle smooth and vacuum up  This is a very old school grind.. Some of the newer offerings and lobe designs would be give you even better street manners and still have some top end punch

[My427stang]

Royce nailed it, not radical, not modern, basically a cam that Ford used to use.  It'd like a little more compression than a modern cam would.

FWIW, I considered that cam for my 445 truck, advanced like crazy, but the low lift really hobbles making any power. 

[Ford428CJ]

I would run it! Like the guys have said... I ran a solid baby roller that was close to that 565 lift Dur @ .050 228 & 234 on a LSA 110. Great street cam in a 428, lifted, 35's & 3.50 grears

[machoneman]

This would better, save for the very high elevation!

http://www.lunatipower.com/Product.aspx?id=3040&gid=339

Some many years ago, I asked some area Pro (Stock & SS) racers why they never attended the NHRA Mile High Nationals. For the carb'ed guys, they said that even with 14-15 to 1 compression ratios then in use, to win there one had to invest in even higher c/r pistons (where possible) to offset the huge drop in HP due to elevation. Heck, even many of the supercharged racers skipped the race since even though they could easily up the blower drive ratio, the all-important 'tuneup' notes then went out the window, especially critical in a nitro engine.     

What is the max c/r you intend to run? Obviously, the fuel is critical here but I do wonder just how high a c/r one can successfully run at that altitude on pump fuel and not detonate that sucker to pieces

[Ratbird]

The CR is 10.5 to 1.

I told the builder I kind of wanted the best of both worlds, keep the torque and add some HP. He's a born and raised Albuquerque guy so he knows the area. Albuquerque is a mile high, identical to Denver. I'm about 45 miles north up past Santa Fe at 6800.

It's supposed to run fine on pump gas. All we have here is 91 octane. Is that good enough or would you recommend an octane booster?
The heads are c4ae-g6090. He put CJ valves in it but advised against hardened seats on account of the lack of room in the head??? It has upgraded springs and he did a regrind of the rockers. decks etc - shims as well. I have FPA headers with an Edel RPM Performer intake and Edel 1407 carb with the correct metering rods and jets for our altitude. 4 speed toploader (close ratio 1 3/8 shaft) and dual friction centerforce clutch. I'm not a wealthy man and was only looking for the 400 HP range cuz of budget. He guessed it would be about 380-400 HP and torque around 450.  I run it with a lead additive and of course Quaker state "Defy" oil that has the ZDDP stuff.

I took the distributor to him so he could curve it on his machine. He told me to run it at about 10-12 degrees advance.
 
Does all that sound about right? I know this forum is for higher end more precision builds and cars, but any advice on gas, etc would be greatly appreciated.

I had told him I like the old school stuff, it's in a rusty 59 T-bird.

regards, Dave J

[cjshaker]

Like the others said, that is definitely NOT a real radical cam. Old school and probably a nice street cam, but the .050 duration is pretty mild and so is the lift. That just means it has soft ramps which will be easy on the valvetrain. With the total duration numbers it will still have a performance sound at idle though even with the 114LSA.

10.5 compression is cutting it close with only 91 octane in my opinion. If you keep the quench as tight as you can go, and stay on the conservative side with timing it might be ok. The altitude won't help matters, but the 10-12 degrees initial will if the curve is conservative to match.

He's right on the hardened seats on the C4 heads. The intakes don't have much room to support the hardened seats. I ran into this problem building the 390 in my truck. About 1/4-1/5 of the seat has no support because it broke through to the port when cutting for the hardened seats I had installed. It hasn't been a problem in the 20 years it's been together, but it's still something that I don't like and probably won't do again if I use another set of C4 heads.

[bn69stang]

Lunati has a cam thats just a bit bigger ,  228-235 @ .50 and 536 on the lift on a 110 lobe and it works with power brakes , and you should be fine on pump premium , don t think you need octane booster at our altitude with that compression . IMO  Bud

[bn69stang]

Machoneman is right on as well , have a friend running the cam he posted in 428 , iron heads with stock cj compression and 3.50 rear gear . It s a great street cam ..Bud

[Ratbird]

Thx Bud, Anderson told me premium pump (92 octane) should be fine. However up here in the Los Alamos and WR area all I can find it 91. It seems to be OK, not pinging etc. Maybe I'll try a booster this spring just to see.

thx!

[bn69stang]

Yeah its all 91 octane , i have nt seen 92 or 93 octane . Besides im sure Doug slowed the curve in your dist to keep you from detonating .. Bud