Mark W. Winning

Over the past few months, I have been putting parts together to build a TPI 383 for my Firebird. Please take a look at the list below and tell me what you think. All the parts are sitting in my spare room, now I just have to assemble it.

Chevrolet 4 bolt, one peice rear main roller block bored .030
Summit Cast 383 crankshaft
Keith Black 10.3:1 Hyper Pistons
1995 LT1 5.7 rods with ARP bolts
Comp Cams 266HR-14 Roller Cam (Dur. 210/220 Lift .500/.510)
Comp Cams Roller Lifters
Comp Cams 1.5 Aluminum Roller Rockers
Trick Flow G2 Aluminum Heads 2.02/1.60 Pocket ported
Port-Modified Edelbrock High-Flow lower baseplate intake
Intake ports gasket matched
Runner ports widened slightly
EGR block-off plate installed
SLP Siamesed runners
Accel adjustable fuel pressure regulator
Lingenfelter/Accel High Flow 22#/hr fuel injectors.
Stock upper plenum and throttle plate with a Hypertech flow booster installed.
GM ECM #01227165 (85-89 MAF system) with an ADS performance chip (88 350 TPI),
Stock MAF sensor,
Rebuilt HEI distributor with MSD ignition coil installed
MSD 6AL
MSD Spark plug wires
Hooker Shorty Headers
Custom Y-pipe
Gutted Cat
Flowmaster 3" cat back exhaust system

Thanks

Mark

Brian Felts

I think thats going to be a hot combo, however you are going to need a better chip to run it. I would worry about running a little lean in the upper RPM. That being said with a custom chip I think you will have a very fast car.



Brian

Mark W. Winning

Yeah, I kind of figured as much on the chip. The chip was used on the exact same combo, except it was a 350 and not a 383. His motor showed lean at the higher RPMs. I figure the chip should work well enough for the breakin period though. I am planning to setup my laptop for scanning and get a programmer.

Mark

OMINOUS_87

Injectors might be a bit on the small side. The cam also seems small for a 383. Since it is still waiting for assembly I would recomend port matching every single intake part you have and removing as much alluminum as possible. You are gonna need all the help you can to try and properly feed a 383 with an LTR setup.

Roostmeyer

iTrader: (3)

I don't think you would close to maxing out your injectores at all. Bigger injectors aren't going to give any gain unless you need them and will only worsen idle quality a touch. I do agree though to port match everything you can, expecially the slp runners and plenum. Also agree that does seem like a very small cam for a 383, even if it is an LTR setup.

Sounds like a very good setup post some before and after timeslips after your done.

badburban

I agree the cam is a bit on the small side especially considering those trick flows have 195 cc intake runners. They are definitley gonna like a bigger cam (Think lt4 hot cam). Ive got a 215/224 lunati roller cam in my burban (6300 lbs or so) with some SR Torquers and she screams. The bottom end (till about 1200 rpm is a just a bit soggy but thats with a stock stall convertor. When I build the trans the new convertor will solve those problems. But all in all your set up sounds very nice. I cant imagin how fast that would be in a 3200 ish lb car.

Josh

1bad91Z

iTrader: (1)

Strokers like to breath and make alot of torque. The LTR style intakes make alot of torque and not enough HP and doesn't flow all that great to feed a stroker. A better intake that would feed your 383 better and make alot more HP at the expense of a little bit of torque (which would be abundant in your case), would be the Holley stealth ram or TPIS mini-ram / LT-1 intake.

Next, I would pick a different cam. Something along the lines of my cam (CC XR276HR-12), but get it with a 114 LSA and 110 ICA.

Finally, computer tuning is the KEY to success. The stock chip wouldn't even fire up my car!

Doing the above would make your car ALOT faster than your current combo. But, you would still have fun with what you have.

Good luck!

Mark W. Winning

I have to push a six speed, so I was shooting to keep the low end torque down low. If I was pushing an automatic with a stall convertor, I think bigger cam might be the ticket.

I was looking at the Holley Stealth Ram and it gave up about 40 lbs of torque across the board until the higher rpms. It was definately better upstairs. They did a pretty good write up in the July GM High Tech. They even used the same spec cam as mine, but it was not roller.

Maybe once I drive it for a while and see how it does, I can decide if I want that torque/hp trade off.

My only other real concern is the ECM and wiring. The TPI system came of an 89 Vette with an automatic. I am going to be running a six speed. Should I get a painless harness? Keep the stocker? Are the ECM and BINS the same for auto and stick cars?

I just cannot wait to see what this thing will do in a 1/4 mile. Should be fairly fun!

camarojoe

I agree with the others about the cam being wayy to small. Go with something that has at least 230dur. on the intake side at .050 lift.

1bad91Z

iTrader: (1)

I'm pushing a 6 speed just fine with my 355 !! Trust me on the cam, go bigger. The next thing is you have to figure out if you're going MAF or SD. Yes, the .bin is different for a manual tranny car, but the harness for the auto will work. I'm using my stock wiring harness that my L98 350 with auto tranny came with. The biggest pain in the *** about installing the six-speed was cutting the whole in the firewall for the master cylinder and mounting it in the correct location.

Dragroc

I'm with what 1bad91Z said...totally.

Mark W. Winning

I guess I should have added a little more info. I installed a carb'd 355 and a six speed about two years ago. I also bumped the rear gears to 4.11's, blew em up and installed 3.73's.

My current motor is a 9.0:1 355 with Dart Iron Eagle 180's, CC XE262, 1.5 roller rockers, Holley Avenger 670 and hooker shorties. The car runs fine, but lacks the low end hit I would like. Unless I am really hauling butt (75+), six gear seems to lug the motor. At the track she just missed the 13's, but I hit 4th gear crossing the finish line.

I drove my friends 89 Vette with a 355 and 700R-4. The car felt REALLY strong. From a light he killed my car later that night. He pulled his setup and went with an LT1. I bought the cam, lifters, heads, entire TPI, MAF, ECM and wiring harness. Instead of building the 355 to match his, I wanted a 383.

Now you know the whole story!

I am looking for a motor with a good of idle pull and enough low end torque to make use of the six speed in my 3500 lbs car, and still run a/c.

I could do all of the things suggested above, HSR, bigger cam, and anything else that will boast HP, but I may do that at a later date.

OMINOUS_87

Well if low rpm hit is what you want you are gonna have your hands full with that combo! If you have ever been in a TPI 383 you know what i mean, the hit like MOTHAS! It will run strong down low but will run out of breath real quick with that cam but apparently this doesnt concern you as you want all the power down low, its all good. It actually sounds like a pretty good combo, the only thing is though that will definitely giving up some of the massive torque you will be making as the heads are a bit on the big side for your plans.

Aslo what are full specs on both cams, the one you are running now and the one you want to run? dur and lift @.050, LSA

ctandc

What's up with everybody wanting to rev to the moon to make power ?


Port the intake out, match / smooth the runners, port the plenum.

The 383 is gonna be FUN on the street and track with this combo. You're cam is right where you're TPI is gonna shine.


Build the engine to make power from @ 2000-5000 RPM....mid range power is the TPI's other strong point.

And MORE Importantly, it's an absolute BLAST On the street, and it makes shifting / driving so much fun when you don't have to rev the crap out of your engine to feel like it's pulling.

My 350 TPI is MILD, and since the T5 swap ( .63 OD '92 World Class tranny ) and with 3.23 gears, the car is a BLAST around town.

I don't even normally use certain gears.....alot of times I'll rev 1st to about 3500 RPM and then shift to 2nd, go to about 3500 or so, then shift straight to 5th, and it doesn't bog a bit.


75 mph on the Interstate turning 2100 RPM = 23 mpg highway / 18-20 around town


Don't jump on the "peak HP" bandwagon. I don't even look at peak numbers, look at the torque / power curve... stroker TPI engines with mild cams have a FLAT line...they make the same power throughout a wider RPM range. Only problem is traction related


HTH

Mark W. Winning

My whole view on this setup is that I bought a working combo, minus the fact I am bumping it up to a 383. As a 350, this motor rocked in a Vette that was just as heavy as my Firebird. The swap to TPI will be hard enough without my mucking things up by changing the combo. From the great responces above, I think I have a good combo that has room to grow.

Now, six months or a year after riding around and tweaking this combo, you may just see a post about what to do next. I really like the Holley Stealth Ram. So, I may just up the cam and install the HST at a later time.

Mark

Mark W. Winning

I have the Keith Black hypers and was wondering what you all recommend for rings on this puppy. Normally, I just use the race rings, but since I am not spraying or boosting this motor, I am not sure they are the best choice.

OMINOUS_87

I used a Speed Pro set on mine. Just note that you have to gap the top ring larger than normal dude to the fact of how high it sits on the slug. Read the directions completely and gap properly for your application otherwise your top ring could butt and bye bye piston! If you have a further question just let me know.

Mark W. Winning

Well, you guys kept talking about the cam and I guess the car gods agreed. Last week, while cleaning the garage, we got a little rain. My cam and box got wet, but I did not know it. Needless to say it is well beyond ever being used again. It was a Comp Cams #08-304-8, 210/220, .500/.510, 114 centerline.

I now need to pick a new cam, but with a reduced base circle this time, since it is going in a 383. I have not idea how this motor is going to breath, but I would like to make and keep a ton of torque down low to make my T-56 more fun.

Can you guys give me some good cam suggestions?

Thanks

Mark

86 IROC

iTrader: (3)

If you stick w/ the LTR set up... LT4 hot cam, XR276, CC305 - or something similar. If you go with a shorter runner intake - CC306.

OMINOUS_87

Well I think 1bad91z is the first to run the XR276HR-12 in a LTR motor, he reports its all good. My vote would be for the cam one size smaller XR269HR-12. I just got my Superram 383 running with the XR276HR-12 and damn she is raspy. In fact it sounds so damn good out of the exhaust I just sit back behind the pipes and listen until I get light headead, and then step aside!!!

Either or I vote for Comp Cams!

Fevre

You don't need a small base circle cam, you can grind the rod bolts slightly to clear the cam, it is common practice. It removes very little bolt head material will not affect it's strength that much. I also agree a bigger cam is in order, just take the the cams recommended rpm range and subtract 500 to get what the strocker will operate in. Also subtract 500 rpm's from the stock tpi's rpm range too so you will only be good to about 4500 to 5000 with all the porting. I would really look at the LT1 intake, with the stroker and high comp you will gain low end grunt so you can run a bigger cam and not loose low end but will gain some hp up top in the 4500 to 5500 rpm range. Matched right your eng will pull form 1500 to 5500 rpm's like no one's business. I am working on a tpi/LT1 Fi system for my vette and I have a Crane roller cam that is 222/230 .540/.560 and with my carbed 9.1/1 comp 350 it pulls from about 2000 to 6000 very nicely. I look forward to having that cam in a FI supercharged LT1 intaked stroker.

OMINOUS_87

Agreed, you do not have to get a small base circle cam, I just ground down the rods in my 383 to make things fit. .050 is all the clearance you need.

Rippin92RS

Someone up the page said his heads might be a little too big. What heads would you reccommend? I was looking at the Pro-Toplines but what CC? 180?

Also, What is LTR?

Mark W. Winning

Almost forgot about this post. I finally got all the hardware back. The block is bored, line honed, etc. I had the mains studded.

Then, I changed my mind. While the block was at the machine shop, I bought a 98 LS1 Trans Am. Now, this motor doesn't have to be so streetable. I am tossing the KB hypers and the gap-less rings in favor of some JE forglings and some sprayable rings. I have a TPI plate good to about 200HP. That changes the whole cam thing. Should I use a NOS cam or go with a good roller and just spray on top of it?

Mark