so I am readign the thred https://www.thirdgen.org/forums/tpi/...ealth-ram.html
and the
http://xtremecarzone.com.au/index.php?showtopic=386
they use the XR288HR on the 383 with 10:1 comp

well I am building a 383 with close to 11:1 comp. i considering the 292XFI cam.
but I am no expet with cam's, so maybe ther eis someone that hae done this and can tell me.

my engine have the stelt ram with some modifications. I have a linenfelter throtle body 58 mm and some porting and work to match my 210 heads with 64 cc camber. my converter have a stal speed around 2500-3000 and my rea axle is a 9" ford with 355:1 gear.
car is used for street legal drag.

i just want to hear your opinion about this set up. maybe I should go a bit down on the cam.

 

I've had some experience with a 280xfi cam in a 360" motor. Was a nice cam that wanted to pull to mid low 6000 rpm range but it had valve float at 5700. You need a good stiff spring for the bigger XFI cams. The lobes are pretty aggressive. Alot of guys here have results for the 280xfi cam...its a good cam that fits most 355-383 applications. Good lope in a smaller 350's motor but idled well enough to be a good street driver too. Definately likes alot higher stall speeds in a smaller motor. I'd run closer to 4K rpm in a 355, 3600 in a 383.

The 292 is a good deal bigger and would pull to well over 6500 in a 383. I've seen it in a good head/intake LT1 and it went to 7K rpm and hadnt peaked yet Its a good cam for a aggressive 383+ inch motor looking to make power over 400-415whp in a automatic. 210cc heads are a good choice for this but will need a strong double spring like Patriot extreme golds shimmed to 160-165 lbs seat pressure and ~400lbs open. LS7 lifters should handle it although morels would be better but very expensive. 3/8" pushrod would be nice if you can fit them or buy the stiffest 5/16 rod you can find.

To get the most out of it, i'd go 3600-4000 stall and much more gear but thats all gonna be harder to hook on the street.

 

well I have a problem.. my current spring say "1.400/.650 lift springs" on my build sheet. I don't get a thing out off that.. but the cam was a melling 22404 cam..
this cam was not compatible with my stelt ram....

but you say that the 292 cam need 400lbs open, then maybe my spings from my melling fit to this comp cam...

can you get anything out off those number on my melling cam?

6500 is quite high, can I pull my scat 9000 crank and forged flat top pistons, 4 bolt mains up to this?

 

Thats a solid flat tappet cam... 258/266 duration which would make it abit bigger than a hydraulic roller on duration with lash accounted for...typically will knock off 8-10 deg of duration but will depend.

No idea what your springs are, i'd replace them. Solid flat tappet cam usually run in the hydraulic roller range for spring pressures but not 400lbs open pressure. Patriot Extreme gold spring kit for LT1/SBC will work if you have standard 11/32 valves or use the ls1 kit for AFR 8mm valve stems but AFR has a upgrade spring that works fine, 8019 springs. Not sure what heads you have.

Why isnt it compatible with the stealth ram? Stealth ram will take a good variety of cams just not TOO much overlap since it has a longer runner than say a miniram/LT1 intake but even then, guys are starting to see improved manners with wider 110lsa cams over the old tried and true 107-108 lsa cams. XFI being on a 113 is kinda soft, i'd like to see it on a 110-111 but that will make idle alot more aggressive. Stealth ram just needs ported well to make big power and rpm.

I got a big 246/252 on a 113.5 lsa cam in my 400 turbo motor and its got a good deal of lope at idle. 383 it would be pretty rough. Would require higher idle speed for sure.

 

well, the melling cam did idle around 1000+ rpm.. but vacuum was hard to "find" and i had to run 30 degrees ingition BTC at idle..

 

Thats sounds about right... Thats a pretty big cam. I ran 28 deg on my 383 with a 950 rpm idle with a 230/245 109 lsa custom cam. XFI with its wider 113 will give alot of vacuum back and be alittle tamer at idle.

 

ok. so the lobe seperation give me more vacum. (I am not into this cam spec)
i think I will go with the XFI cam.
+ new springs around 400 lbs open and 160 lbs seat
+ roller lifter
and use my existing roller rockers (1:6)

Thank you for your help and experience!

 

think I found the sping rate on my existing springs.
140 seated and 350 at 0.600 lift
so they are a bit "off"

I might go for the patriot gold, good price on the complete package

 

Its probably gonna be border line. If they are good to .650 at the current install height, you could try shimming abit to get that 140 up to 155-160 but it may leave you alittle tight on lift clearance with that cam.

If you are not a hyd roller block using the OEM type setup you'll need retrofit lifters, which I'd recommend Lunati, Morel, or possible Howards top end stuff as they all should be the same Morel lifter Pricey but well worth it. Worth extra power over a OEM lifter replacement. They wont bleed down at high rpm or high spring pressure.

 

the block is a 87-94 so it should be a roller..
I think I will do this the easy way and by this:
https://www.patriot-performance.com/...&cat=52&page=2
this have the shims and everything for the springs.
then the cam and lifters:
http://www.compperformancegroupstore...ory_Code=HRXFI

 

If its a roller block I'd rather try the LS7 GM lifters...they are around 120 bucks now and work great with these type of cams. The Comp lifters may be OEM type replacements with weaker valving...not their top of the line rollers but I'm not positive on that. Just thinking you'll save abit of money using LS7's over the comps

 

so you think off this roller then?
http://www.summitracing.com/parts/NAL-12499225/

 

Yeah those are the ones I've used in my motors.

 

oki..
ten I need:
http://www.summitracing.com/parts/NAL-14101116/
and the guide it self. but cant find the part number on that..

 

GM used to make a conversion kit ( available from Summit ) that had the hold down spider , the 8 dogbones and 16 HD lifters ( best factory lifters before the LSX lifters ) for about $220
Trying to find the part # for you.

In any case you may be better off getting the dogbones and spider used from someone parting out a engine in For Sale Dept
or even placing a WTD notice

 

I just ran into another problem! I think!
with the 383 rotating kit, the cam have a max lift about .550
if lift is more the rods can interfere with cam.... This happens when piston is in top position, then the lobes are down...
is this true?
if this i s true, are everyone that have a 383 max cam with .550 lift?

 

Not sure I understand what you are asking with the .050 numbers but you can sometimes have a rod to cam interference but MOST stroker kits or rods designed for strokers have adequate clearance. I ran eagle H beams with a .383" lobe and cleared fine. I have a .400" lope clearing my callies compstar rods but the cam is on a smaller base circle.

If you are concerned, order the cam on a little smaller base circle but I dont think its necessary if you have the right rods.

 

I did write wrong numbers in my post! (I correct it)


My plan was to use this stroker kit on the engine:
http://www.skipwhiteperformance.com/...tem=3831PCFT60
but in the text on this page, there are some limits with 550 lift on the cam.

but I might be very wrong mixing up with valve lift and lobe lift.. lobe lift is .366 so that should be ok, if skipwiteperformance are refering to lobe lift in the text!

 

You will be hard pressed to find a .550" lift Lobe! Thats a big bad boy solid roller race setup that will yeild near .935" with a 1.7 shaft rocker And if you need that cam, you wont be using Scat rods...

He's refering to cam lift at the valve. Its gonna depend on the actual install of the cam because the lobe can be at different areas vs the rod end depending on the actual cam installed centerline.

I doubt the xfi cam would have issues with the scat rods but to be safe, check on assembly or just buy a smaller base circle cam.

 

oki..
I think I will try this then..
I am waiting a shipping quote for skipwiteperformance...

and I found a hold down spider and the dogbones on ebay. there will be orders from different companies this time, but so be it... I going to build this engine, I stated so.. (-:

 

Just curious...what efi system are you using and how you tuning this? Your info says 87 so its a MAF car. That will make things nicer but it will max out that MAF sensor very early and you'll need to heavily rely on the PE vs RPM enrichment table It only goes to 6400 rpm but for 6500+ rpm just put a large value in at 6400 and it will hold that to whereever the engine goes

 

hi

there is nothing left from the original tpi set up....
I use a modified holley stelth ram. ported, bigger injectors and a lingenfelter 58mm throttle body.
I use a holley comander 950 pro ECU and I got my hands on a self tuning additional software.
my wb O2 sensor i s controlled from a VEMS O2-controller..

engine bay:


engine with the looong tube headers..

 

I like the 280XFI a lot.

 

EDIT: First i apologize for digging up the thread, but what octane you plan on running? and oor, should he be expecting more power? these are flywheel numbers right?

I'm not trying to thread jack but I dont want to start a thread of my own, rather just lurk around with no one but the search button for a friend...

 

planing to use 98 octane, we have that in my country!
I will try the 95 octane, but if this create ping-trouble i run 98..