Another cam question...
 

What do you guys think about this cam that comp recomended to me?

07-466-8 - XTREME Fuel Injection (XFI

Going in a 383 lt1 stroker/approx 9:1 compression blower motor on about 8-10 psi (vortech). Advanced induction heads. 1.6 rockers. 3.73 rear. 2800 stall.

Don't want to rev it to the moon for shifts, would like around a 6200 shift point. Also dont need every bit of power out of it. Since its a street/strip car, need a decent idle but still like the lump.

Any help would be appreciated.
Thanks.

Re: Another cam question...
 

Understand Comps LT1 rpm ranges are lower than reality. The extra displacement you plan on will help reduce the amount it is wrong so your self imposed 6200rpm limit might be in the ballpark despite Comps 5800rpm range.

IMO the compression is a little on the low side, remember the iron head LT1s were 10:1 on 87 octane, so the LT1 can use a lot of compression compared to most other engines even when boosted.

With a built motor I would allow for a little more rpm, the stroke will help make sure you still have lowend. I would say turn it 6500rpm and get a cam say 6-8degrees bigger. This wont be radical or anything LOTS of guys run cams in the mid-220s on stock shortblocks so in a 383 they can be quite mild.

Have you considered having Phil spec you a cam?

Re: Another cam question...
 

9:1 is kinds a ballpark with the compression calc I used. Heads were milled when they did my heads originally, using -31cc diamond pistons along with fel pro 1074 head gaskets. Block is not decked. I did think the cam they selected did seem smallish.

6200 was just a starting point...6500 shouldn't be a problem either (Callie's dragonslayer/comp star 6" rods).

Thought about contacting advanced or Lloyd or cam motion. Just wondering also what some other guys here are running for some ideas.

Re: Another cam question...
 

I am running a CC 224/236 .571/573 116 lsa and like it very much. Like you, I don't like revving to the stratosphere. My shift light comes on at 6000 so by the time I shift, I'm probably around 6200-6300. See my sig for my mods. My CR is around 9.2-9.3. Your 9.1 CR gives you room to up the boost later if you want.

Re: Another cam question...
 

Seems like 114 lsa is the norm...how does the 116 lsa differ from the 114 lsa...good idle/power?

Re: Another cam question...
 

Went with a 116 lsa to make sure it would pass emissions. My old cam was a cc305 with a 112 lsa, so I thought I would be giving up a lot of low end and lope. Very little difference--notice it the most pulling out from a stop. Pulls hard from around 2500 on. Still hits a good lick at idle. With your 2800 stall, you would be well into the power range. I'm even thinking about going to a 3.50 rear gear because 1st is pretty much useless with my 3.89.

You said your heads were from Advanced--you might talk to them and tell them what you want and see what they recommend.

Re: Another cam question...
 

Talked to comp and my builder today...he ordered this cam for me, said itshould be good to 6500 rpms.

07-468-8 - XTREME Fuel Injection (XFI

What do you guys think? Is it too big a cam??

Thanks.

Re: Another cam question...
 

That seems rad to me - I'd like to hear how it turns out. I have a way smaller cam and uncontrollable power at most speeds, so I wonder what the strategy is behind all that duration. Kind of doubt that falls into the streetable category, but then again, I'm no expert and like to see what the other guy does with his crate.

Re: Another cam question...
 

With the wide LSA I would expect drivability to be fine. As I had said though Comp's rpm ranges are wrong. Best guess is they just used the same numbers they would have for a dual plane gen 1.
fergymoto tried this cam in a stock shortblock with Lingenfelter heads and it had not peaked when he ran out of pcm at 7000rpm. Your heads are better yet but you do have more displacement. Still though I would expect this to keep making power way past where you expect, might not even have the rpm capability in the pcm to get the shift extension right.

Re: Another cam question...
 

love this site...told the builder to cancel that 242/248 cam...did seem over the top...he's a circle track racer.
went with a thunder racing grind 224/236 on a 114 lsa.
hoping for the best or at least close...lol

:D

thanks again guys...appreciated the advice!!!

Re: Another cam question...
 

With that kind of overlap you're definitely going to tell it has a cam in it. You're going to need a bigger stall too.

Re: Another cam question...
 

Now you went a bit on the small side and on a 114 with a 383 it will not be lopey and with a blown stroker you are going to push that stall well beyond 2800.

Re: Another cam question...
 

I ran a 224/236-114 Comp cam Xtreme (NOT XFI) on a 383 with a Vortech T-trim. At full stock weight+, I ran 10.40 at 133 mph and made 550 rwhp through a TH350 and loose converter. The converter was supposed to be a 2800 (vig), but stalled much higher with all that torque. Just another data point. . .

Re: Another cam question...
 

Mike..what gears/pulley combination did you have? What were you shifting at? I see you're running that cam in your current set up...Hopefully I'll like it as much.

:D

Re: Another cam question...
 

I'm going way back in the memory banks here, but I think it was a 3.50 gear in a 9". The pulleys I believe were 6.66/2.75. Boost was 13 psi, but went up to 15 if I removed the whole inlet piping and filter assembly. I was shifting at 62-6500. I later ran that cam with the turbo setup, but then switched from the 234/236 to a 236/236 so-called "turbo grind". It was a turd, so I wound up putting the 234/236 back in it. I sold the car about 4 years ago, though.