Just as it says. I am having a 383 built that will have a HSR on it and wondering what kind of power it will make. Motor will have 10.1 compression and profiler 195cc heads.

I basically want to be happy with my cam choice. Ive been looking forever. I have to use an off the shelf grind number to give to the builder.

 

I don't have any dyno numbers to show, but the 383 in my 86 bird has the XFI280 cam and AFR 195 heads, I like it

 

Auto trans with ported hsr, with right valvesprings with box stock profilers, could see 380-410 whp

 

Thats respectable numbers I think that is the cam I am going with. How well would the 268 do in a 383? I know the 280 will pull hard above 6k but I am mostly a beat it around town kind of driver taking it to car shows and stuff.

 

Its a torquey cam in a 383, peak hp in the mid 5500 range, all done by 6000. Not bad but mild for a 383 imo. 280 is a better fun cam for a street strip car. Comp doesnt offer in betweens like a 276xfi but the lobes are available. A 224/230 type xfi cam would be great for a more street driver oriented 383 and a good cam for a 350-355. The 280 in a 355 works but its a top end screamer and has good deal of lope. Soggy under 3600 rpm unless you have high compression

 

Thanks for the info about it. I think I have a pretty solid decision then going with the 280. Do you recommend a specific torque converter stall speed for the 280? I have a 2500 now on my 700R4 and was thinking I need to step up to 3k but I see them advertised from 2800-3300.

 

It will drive ok with 2500-3000. Best strip performance would be with around 3600-4000. I tuned this cam in a 360" sbc with stock converter and was able to drive fine just real lazy in the low rpms on the low comp smaller cube motor. 383 stroke will help the bottom end

 

If I remember right the lobes are available to grind a "276XFI" cam. Look in the lobe catalog. Not sure why they didn't offer it as a standard grind. Same issue between the 280~292. It's like they make larger jumps with the standard grinds. Also, I went with a 112LSA and think I shouda gone a bit tighter on my 414. Used QNI lobes though.

 

Lunati voodoo is same way. They have a 270, a 282, and a 294. Nothing in between but i bet they have the lobes
Xfi has lobes in 2 deg increments so you can do 220, 222, 224, etc etc. i'd love to see a 226/232 on a 111. Be real nice in a hot 355 or good driving 383

 

My 383 TPI put down 340 rwhp and 370 rwtq, XFI280 with Patriot heads and a T56.

 

What tpi intake parts?

 

Edelbrock lower, ported upper. Runners are siamesed tubing, handmade at the Gale Banks shop way back in the day.

 

Not bad numbers. Def could gain abit with heavily opened up base

 

What do you consider lower comp? 9:1? Just curious because I'm thinking about this cam for my 360, but I'm only at 10.5 and don't want to have poor bottom end.

 

I used the Comp XFI lobes 3015/3036 to build a custom spec cam for the 355.
224/230, 274/280 w/.574/.569 110 LSA, 106 ICL.
Except for being a little on the noisy side, it's proving to be strong performer. That comined with smallish 180cc iron heads and a 10:1 CR is seeing trap speeds near 109 in 3650lbs.
The next step up in the lobe profile catalog would be good match for a 383. Add a little LSA for the fuel injection perhaps with the bigger engine.

 

Depending on the LSA of the XFI280, 10.5:1 might be as low as you'd want to go and not give up some of that lower rpm torque. It's 4% of max hp or so for full point of compression change, but the ft/lbs given up is right across the board and that's where it gets noticable.
With aluminum heads, 10.5 and a 280 intake lobe is very doable (Combined with an exhaust profile and angles that are typical). You could even manage it with iron heads. I would think 9:1 and a cam that size is going to leave some performance on the table.

 

It was closer to 9.6-9.8:1 with aluminum head. He wasnt sure. Just def not optimal for that cam. 10.5 is better

 

Comp XFI and there other hydraulic roller lines is very popular on this site, and rightfully so. I ran a 280 XFI in my 383 and it had a good stable idle, great street manners and was easily tunable with efi. But know there are other cam manufacturers out there that make some good grinds, and don't fall into thinking all cams for efi need wide lsa and wide intake /exhaust splits. I went from the 280 XFI to a cam many members might argue is a race or strip cam yet I have more midrange than the XFI had.

 

What cam was that if you don't mind me asking?

 

I'm using the 280XFI in my 388cu. It made 440whp@6300. Check the sig.

 

Those are some impressive numbers I bet that car is fun

 

Oh yes it is! But it needs a little more tuning for better throttle response at the hit of the throttle.