TSP Level 1 350 Buildup info and dyno results

Discussion in 'Small Block Tech' started by Jim Weise, Apr 29, 2008.

  1. Jim Weise

    Jim Weise EFI/DIS 482

    Hi Small block fans..

    I have had quite a number of requests in the last few months for some more 350 info, and have a couple of current 350 projects going. So I decided to come up with a new program for the 350 engines, similar to our 455 program. As with the 455, we start with the Level 1 engine.

    Just finished and dynoed the prototype, and thought I would throw out the info here.

    The goal of this engine was max torque and good HP at low rpm, with good idle manners, for your typical cruising around GS 350. No cams with a rough idle, and works good with low 3 series gears, and a 2500 stall converter. (I will be developing a special 350ci Stage 1 9.5" converter based on this package).

    Just like all Buick's, heads are the key, and I used this engine for a bit of experimental work with the 350 iron heads.

    I laid out my guidelines like this..

    • Aluminum Dual plane intake, Q-jet and no spacers- so the stock GS Air leaner could be retained
    • 9.5-1 compression for use on Pump gas
    • Ported heads with oversize valves
    • No more than 220* of intake duration- for a nice idle quality
    • 1 3/4 headers- shorty headers will be similiar to the dyno sheet shown here. I did not test this particular motor with manifolds.
    • Max torque and HP with a broad flat torque curvewith peak at around 4000, and a HP peak right around 5000 rpm
    Here's the buildup on the prototype


    • 1971 Buick 350, complete Skylark core in good condition, standard bore
    • .030 over Speed pro pistons
    • Actual compression is 9.4-1
    • Full block cleanup and inspection
    • Brass frost plugs
    • My special mix of TA and standard cam bearings
    • ACL Rod and main bearings, .010 under
    • Magged and ground crank, set to my 350 spec of .002/.002 for the mains and rods
    • Resized 71 rods, with TA bolts
    • Standard oil pickup sizes, with stock oil pan and hardware
    • Remanufactured balancer
    • Honed with a torque plate (we machined our own)
    • Moly piston rings
    • Rebuilt stock 71 350 timing cover with booster plate and STG 1 60 lbs spring.
    • TA 212-350 cam, with 218/230 duration .453 lift, 110 LC, standard Buick Delphi check ball lifters
    • HD steel replacement timing chain set.
    • Cam installed at 107* (3*advanced)


    1971 "650" castings including:

    Complete glass bead cleanup and inspection
    Bronze K-liners for the guides
    Street/Strip Plus Ported intakes
    Street/Strip ported Exhausts
    TA 1.92/1.55 Stainless valves
    TA 1436 Stage 1 valvesprings
    Unshrouded chambers (60cc), 3 angle seats, back cut valves.
    Flow 255/167@ .500 (flow sheet below)



    • 1972 750 cfm Q-jet
    • TA Perf STG 1 350 intake (out of the box)
    • TA 1 3/4 Primary full length headers


    • Rebuilt Points type distributor with electronic conversion
    • Stock appearing and loomed plug wires
    • NGK V-power spark plugs

    This engine has great idle quality (13-14" of vacuum at 750 rpm, very slight lope). Low lift and light valve spring pressures keep the valvetrain silent.

    Here's the dyno sheet.


    A nice flat torque curve, with basically 400 ft lbs and 350 HP.. and great driveablity.

    With your complete core engine, carb and headers, this one goes out the door for about $6500..

    stump puller455 likes this.
  2. Matt S

    Matt S Matt


    Thank you for all of your work and the information on this 350. It's good to see that little brother is getting some attention:TU:

  3. rex362

    rex362 paint clear and drive

    "This engine has great idle quality (13-14" of vacuum at 750 rpm, very slight lope). Low lift
    and light valve spring pressures keep the valvetrain silent.

    A nice flat torque curve, with basically 400 ft lbs and 350 HP.. and great driveablity."

    this is exactly what us city slicker tire screecher's need out of our 350's (like me :grin: )

    nice job JW ...and I imagine there will be a level two in the future..
  4. Fox's Den

    Fox's Den 27 years of racing the same 355 Buick motor

    Can't wait to see what the master blaster 350 does. Nice job Jim.
  5. 71skylark3504v

    71skylark3504v Goin' Fast In Luxury!

    I LOVE dyno results! Nice Work! :beers2: In the next year I would like to be able to buy a 350 short block with forged rotating assembly capable of 7k-8k RPM for use with Twin Turbos. Jim, what are my options?
  6. Snowbound

    Snowbound Well-Known Member

    Other than the headers, would it be safe to assume we could get close to these numbers with a 340 small block? I think the key is in the heads, and being they are a different layout, I'm not sure what kind of gains could be had by porting these.

    Any thoughts on the little little brothers?

  7. 71customConv

    71customConv Platinum Level Contributor

    What would the potential gains be with long headers and an 800CFM Q-Jet? Did you see anything in the test that would lead you to believe the 750 was not quite enough carb for the build?
  8. Jim Weise

    Jim Weise EFI/DIS 482

    For that rpm, I would want to see you run a TA/GRP aluminum rod, with a custom dished turbo race piston. Also, some type of girdle would probably be required.

  9. Jim Weise

    Jim Weise EFI/DIS 482

    Your going to have to have headers to get these numbers.

    And I would expect that the 340 head should be capable of near this flow rate, fully ported.

  10. Jim Weise

    Jim Weise EFI/DIS 482

    It was tested with long headers.

    I did in fact try a 950 HP Holley and a 1" 4 hole spacer..

    Maybe another 8-12 numbers could be had with this combo, it showed about 8 ft lbs and 2 HP more, but I would have had to jet it down a bit to opimize it. I did not do that, as we were just seeing if it would lose power with that bigger carb, or gain anything dramatically, and it did neither.

    The vacuum readings at WOT were the same as the 750 Q-jet,(less than 1"HG) indicating that the 750 carb is not a restriction. I would expect no difference with an 800 Q-jet. This particular motor is not working even that 750 enough to tax it..

    The Q-jet would be my number one choice for this combo, as it will drive down the road very well, be very responsive, and get something that almost resembles gas milage, if you can keep your foot out of it.

  11. stk3171

    stk3171 Well-Known Member

    Great job. These are good numbers for a street engine.

    We just got my NHRA stocker off the dino and after all the tuning we managed 358hp. this is a all out duration cam non-ported stock valve-lift combo.

  12. bob k. mando

    bob k. mando Guest

    the power/torque numbers seem very similiar to a 602 GMPP crate motor.

    were you shooting for that or was it just happenstance that it wound up that close?
  13. Jim Weise

    Jim Weise EFI/DIS 482

    I am not sure what a 602 GMPP crate motor is, so any similarity in the numbers is coincidence.

  14. Jim Weise

    Jim Weise EFI/DIS 482


    I have the big brother to what you have there going to the dyno next week..

  15. bob k. mando

    bob k. mando Guest

    I am not sure what a 602 GMPP crate motor is

    check your PM's.
  16. sean Buick 76

    sean Buick 76 Buick Nut

    There will be a X-factor single plane intake showing up at your shop for the stage 2 and 3 level builds.
  17. techg8

    techg8 The BS GS

    great post! thanks for all the work!
  18. mmbs72

    mmbs72 Well-Known Member

    Hey Jim,
    Figured I'd chime in and give a status on how the engine is doing. After taking a far greater time to install the engine and new dual exhaust than desired she's in, looking sleek and running great. I don't have any actual before and after times to share, although I can say that the engine is sweet. It woke this car up and is making driving the car a good solid experience. It idles like a champ (as you noted it should), pulls throughout the entire range and it is a HUGE difference compared to the previous engine. I'm currently running a TH350, stock converter and highway gears, no absence of torque or pick-up to report.

    Too bad we didn't have time to compare the TA 212 vs. the TA 413 on these heads but still agree the 212 was a great ragtop cruiser choice.

    300sbb_overkill likes this.
  19. sean Buick 76

    sean Buick 76 Buick Nut

    Awesome news!!!
  20. Jim Weise

    Jim Weise EFI/DIS 482

    That's good to hear Matt

    Have fun!


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