z71stroker

weee - ordered my xe264hr hyd roller cam, I apologize if you get a headache from reading this lol. I got the spider/keepers and thrust plate for free, whew!

cam specs - 212/218 .487/.495 lift w/ 110 lsa.

Think it was a 106 intake centerline don't remember. I was going to go with the 270hr, but I liked the 1200-5200 powerband for the street, plus it's the super heavy 4x4 third gen *wink wink.

Now I'm having my doubts about TBI though -

355 milled .010? I asked for surfacing but it removed the VO #'s
6" rods
PTL vortec heads 3/8 screw in studs w/ guideplates
set up for .540 lift
speed pro hyper flattops 4cc valve reliefs - sitting maybe .010 in the hole at the most.
magnum 1.52 roller tip rockers
xe264hr cam
rotating assembly was fully balanced
CR was going to be 9.9:1 without the block being milled, so I have to re-check it.

After seeing the 350ho 330hp crate motor push 401hp/428tq with the lt4 hot cam? stock vortecs, long tubes and a 750cfm dp with 9:1 CR, I'm feeling the TBI isn't gonna work anymore

Gunny Highway

iTrader: (1)

That 110 LSA is going to cause a few PROM tuning difficulties.

But yeah, that's a pretty stout cam. . . numbers should be 375HP and up.

BMmonteSS

I've got the comp extreme 4x4 cam in my 350, it specs out at 218 /226 with .462/480 lift, with a 110 lobe sep angle. It's not a cam for a beginner to learn on, but I was able to do it. It has a nice idle with a just noticable lope, and pulls good through the midrange.

Hopefully you have some practice tuning, and a set of 80 or 90 lbhr injectors. You'll probably still need to crank up the fuel pressure a bit too. I'm running 70's @ 22 psi, but I'm only making 300 on a good day.

Gunny Highway

iTrader: (1)

Dyno proven?

MPG?

z71stroker

heads / compression monte? your sig just lists cam / intake / 454 tbi, what's a cam without heads and some compression? valve lift corrects to .493/.501 with the comp rockers

BMmonteSS

I'm not saying the cam is the limiting factor, it's the rest of my combo thats my limiting factor, I have crappy heads. They are 416's with 1.94 valves, the 58 cc combustion chambers bump my compression up to 9.6 with the stock dished pistons that are in it now. My cam with vortecs would make 375-400 easy.

It's not dyno proven per say, just track proven. I'v run a 13.92 @ 98 mph with the combo I have now. Factor in the heavty weight of my vehicle and you get about 265 to 270 at the wheels, which is ball park 300 at the crank. I'm runnin 3.23 gears and I can get 23 mpg on the highway if I drive at a sensible 5 over the limit, but that rarely happens. On my 100 mile daily commute I run 80 mph on the highway and about 20 of those miles are city miles. Driving like that I average 19.5 to 20 pretty consistantly. Thats not taking it easy on it either, that average usually includes a couple of 0 to 60 sprints and at least one highway squirmish with the local **** population. This is where I see the biggest difference between carb and TBI. I had a 750 carter on it for years, and if you go in it just a couple of times your milage for that tank was shot, I only averged 17 to 18 being easy on it.

Here are the things I had the most trouble with while tuning my combo. Keep in mind I was tuning all of this with a swap to TBI with no baseline or prior experience.

1: I was trusting the narrow band too much, If I had a WB when I started I would have been miles ahead by now.

2: At idle my NB is pretty much useless with the 747 I have. My idle needs to be richer than 14.7 using the O2 offset isn't an option on the 747 since it only leans out the mix, the 746 I believe has a way to richen it. I got around this by just running open loop. I also disabled Asynch injector fireing at low engine speeds. This did wounders for my idle. I was going in between Asynch and synch at idle, and it woudl hickup every time it did sometimes 2 or 3 times a second.

3: Getting enough AE or pump shot is tricky with this motor, the 454 TBI combined with the peaky mid range requires alot of fuel when you smack open the throttle. I'm still working on getting this perfected. It's already 10 times better than the carb, but my WB showes me room for improvement. Disabling Asynch at low engine speeds also helped my AE by leaving more room to get the pump shot in. AE is injected asynch, and you run out of time to get all the needed fuel in.

4: Tuning around big injectors requires more than just adjusting your BPW constant. Everything that is fuel related needs a little tweaking.

z71stroker

fudge, I was checking through all the roller gear I picked up for free over at frank's machine and I don't have the bearing for the thrust plate. have to wait til thursday and order something on the commercial account, sob. picked up my new timing setup and cam today was hoping to finish everything up

z71stroker

cam is in - I actually had to turn the rotating assembly over slowly as I put the cam in, the huge lobes were hitting everything lol, but it's in, and there's no issues, except I bent up the pickup knocking it onto the pump, so I have to pick up one, or 2 tomorrow and try again - I was knocking it in crooked, dark garages suck, how do I post pictures?