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Need advice. Building 383 stroker(TPI?)

Discussion in '1973-1991 K5 Blazer | Truck | Suburban' started by coloradoblazers, Mar 18, 2002.

  1. coloradoblazers

    coloradoblazers 1/2 ton status Premium Member

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    The 305 has got to go. I was thinking of building a 383 stroker to replace it. Here's my plans, input is appreciated.
    Block: 350 4 bolt main bored +.030
    Pistons: Silvolite Keith Black hyperutectic
    Crank: Eagle cast steel
    Rods:Clevite 5.7"
    Cam:Comp Cam 4x4 extreme 270 226/234 480/.498" w/ hydroulic lifters
    Heads: world s/r torqers, but my only concern is they wont fit the TPI
    Asperation: 1987(ish) Camero TPI
    All this I want get, and have machined for under $3500. I would do all the work i am physicly/mentaly capable of.
    I hate to use destop dyno, i'd rather have real world results. I want to geat about 400+ hp and over 400 lb/ft torque(across a low RPM curve). Just in the planning stages now, so any help would be greatly appreciated(as well as donar parts-have cash!) Right now my sources are Jegs, Summit, SDPC and junk yards.
    Thanks Alot
     
  2. Blazer79

    Blazer79 1/2 ton status

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    Your plan sounds great. I might just suggest a smaller cam if you want the power down below. Somewhere around 204-206.

    I believe that a TPI will fit the S/R torquers. TPI doesn't fit centerbolt Vortech style heads.
     
  3. zakk

    zakk 1/2 ton status

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  4. CaptCrunch

    CaptCrunch 1/2 ton status

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    400 hp is not gonna happen with stock tpi runners, lower intake, etc. Also you are gonna have to change to bigger injectors for that kind of power. Plus a 400/400 motor is not gonna have the torque where you want it. Look into somethimg more like 325 hp and 400+ ft lbs. of torque. The GM 383 is about that ball park money wise... why not do that and top it with a quad. Then you can do FI down the road.
     
  5. shaggyk5

    shaggyk5 1/2 ton status

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    Talk to BlazzinOR, He's the freakin TPI guru allseeing buddah guy. He's got a TPI 406. He should be able to help you with all this.
     
  6. BorregoK5

    BorregoK5 1/2 ton status

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    I'd agree here, there are many shops that produce great complete 383's that are reasonably priced. I'm partial to Speed-O-Motive from past experience. The smallest of the 4x4 grinds will produce most of your power at the bottom end at the sacrifice of top end while the more radical of the 4x4 grinds are going to move that power band up into the higher rpms sacrificing at the bottom end. When dealing with a stroker, velocity in your rotating assembly can hit a critical limit by 6000 rpm if your not built to handle it. If your thinking about cast equipment then stay down below 5500 with all your power and run a mild cam. If you can afford to sink a fortune into an all forged rotating assembly then I'd reccomend looking into the steeper more radical cam (along with a much higher stall to get past the weight of the forged equipment, rotating innertia and all). The latter would get you well into the 400/400 range but would be more focussed on burstable power as opposed to everyday longevity(daily driving as opposed to drag runs). If you plan on using this truck for everyday things then focus on some of the other aspects like how much heat a high stall converter will produce, what kind of gas consumption you want to settle on and what type of hardware you want to spin and compromise from there. What you've listed above will get you pretty good gas mileage but the small injectors coupled with the steeper cam will narrow your useable power band. going carburated in the mean time would help and if you decide to get radical with it, you can sink some cash into a full flowing TPI when its convenient as suggested above.
     
  7. BurbinOR

    BurbinOR 3/4 ton status

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    Capt and Borrego have some good ideas there...........to get the motor you want AND TPI it all at once will probably blow your $3500 early on...........might plan this in two steps. Get the motor built WITH the head configuration you will be able to mate up with a TPI base to start with. That might include Vortec heads, since there now is a TPI base for Vortec heads. I have no idea if the heads you mention have the '87 up bolt config, so check that out. Cam selection, IF you want TPI now or later, needs to be considered..............I suggest you discuss with the cam supplier (Comp Cam in your case) what you are planning, and make sure they know what you are up to with the FI stuff.........it matters a lot.

    With TPI you have two choices - MAF (mass air flow, utilizing a mass air flow sensor on the inlet air to 'measure' the air going into the motor) or SD (speed density, using manifold air pressure <or vacuum as the interpretation goes> to adjust for air flow). SD came out in the 90 model year, all before was MAF. MAF is reputed to be able to handle a more radical cam profile, since I have SD and no real experience with MAF and a rad cam, I can't comment. What I would suggest is going to www.thirdgen.org , sign up as a member and start READING the TPI board..........a lot. Post questions about cam choice and TPI options and let the experts inform ya.

    Tho it was commented as such (thank you), I am far from an expert on TPI /forums/images/icons/shocked.gif, I have an extremely good combo in my Blazer and understand how it works, what makes it work, and how to keep it working. Picking cams I know little about, mine was chosen for me - and since I'm in Chicago and not near my info, can't tell ya right now what the specs on my cam are right now.

    TPI with stock runners has a reputation of not flowing much over 4800 rpm, even on a 350, let alone a 400. My 406 pulls very strong up to 5000 rpm, so some of the flow issue, tho probably supported by dyno results, are not as significant as you might believe. It's not like it feels like it is running out of air..........guess I should try to rev it over 5K and see what it does, but in reality I have NO need to rev over that. Was running the sand dunes out at Sand Lake WOT and never ran out of power, so that was my acid test. Anyway, there are lots of other options on TPI to increase the airflow - Mini ram, Super ram, Holley makes a port injection setup, Lingenfelter, guys on thirdgen porting/siamesing the stock bases/runners, LT1 intakes grafted onto TPI manifolds (adding the distributor hole), etc. In short, tho a stock TPI makes your motor happy, happy, happy /forums/images/icons/laugh.gif, there are options for someone who feels the need to rev the motor to the moon.

    400 lb/ft of torque on a TPI 383 will be simple, the hp figures might stay below 400 but you won't feel like it is weak, no doubt. I want to dyno my motor someday just for the heck of it.
     

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