Need best "bang for the buck" for my 350

Discussion in 'Small Block Tech' started by NJBuickRacer, Mar 16, 2002.

  1. NJBuickRacer

    NJBuickRacer I'd rather be racing...

    I was wondering what I can do inexpensively to my 350 for now until I have my 455 done to get more power. The motor's a little tired but runs smooth and doesn't tap/knock/smoke. It's the original engine in my '72 GS, I'm installing 3.73s this week and throwing on a pair of hi-flow mufflers I have lying around. I already have an HEI installed and played with the carb but didn't get enough improvement from these. Any recommendations as far as tuning, etc?:Do No:

    Thanks,
    Artie
     
  2. brblx

    brblx clueless

    i'm not the brightest peanut in the turd, but:

    if everything works right, carb is built well, ect, i'd go for maybe some headers, a new intake, and a new cam. since we have a lack of good heads, porting your stock ones might help out.

    that's about what's planned for mine. of course, to do the above, other parts may be needed (new rockers for a particularly hot cam, ect). nothing's really cheap, ya know.:puzzled: :ball:
     
  3. Mike Atwood

    Mike Atwood The Green Machine

    I can honestly say....that's one I haven't used ....yet:puzzled:
     
  4. 72skylark

    72skylark 4 Doors of Fury!

    you didn't mention what type of carb you have, but putting on a 4 brl will make a big difference if you have a 2 brl. Also recurving the timing will make a good differnce. I recommend the Crane kit. The one with the adj. vac. advance diaphragm, and the spring assortment. The HEI conversion alone will not give any power. it mainly eliminates the need for changing points, and will make it run a little better in poor conditions. Make sure you changed you plugs when you did the hei swap, cause I think it wants a different plug, with differnent gap...

    Thoose 3.73 will probabally make that thing launch like all heck. My 2.56 launch pretty hard...
     
  5. NJBuickRacer

    NJBuickRacer I'd rather be racing...

    I do have the 4-BBL already, and went with lighter advance springs to get the advance to come in a little quicker. The adjustable vac advance is in too, I have another set of heads here that I can port-match and install if anyone thinks it's worth it.

    Thanks
    Artie
     
  6. NJBuickRacer

    NJBuickRacer I'd rather be racing...

    I was also thinking about just doing a hone and re-ring next weekend as my 455 isn't going to be done for at least a month or two. I have access to a lift and a fully equipped shop whenever I need it. Would it be worth it to shave .025 off the heads, and throw in a mild cam?
     
  7. Mike T

    Mike T Well-Known Member

    Got a nice little q-jet nitrous kit sitting here in stock...

    Mike T
     
  8. Darryl Roederer

    Darryl Roederer Life is good

    Artie,

    Try and assess the base condition of the engine as it is now.
    Compression test
    Leak-down test
    Spin on a new filter, dry, and listen for rod knock.
    Oil pressure at idle

    Base engine ok? Then move on to the basic tuning tricks.
    Hook it up to a diagnostic machine
    Good spark
    Hitting on all 8
    Timing bounce [timing chain]
    Enough advance??? Too much???

    Everything there looks good? Move on to the induction/exhaust
    Carb tuned out properly?
    Is it big enough? Install the one for your 455
    Exhaust big enough? Install the one for your 455
    Choke opperating properly

    That's all good, move on to the driveline/acessories
    A/C hooked up? Take the belt off
    Fan clutch working properly
    Tranny tight, good converter? Install the one for the 455
    Enough rear gear?
    Enough rear tire?
    Enough rear suspension?

    Everything working properly, tuned out correctly? Then, and only then, consider opening up the motor for rings/bearings/etc.


    The best bang for the buck, listed in order, after all the above:
    #1, 125 HP nitrous kit
    #2, hot street cam [wide LC to increase cyl. pressure]
    #3, headers
    #4, ported heads
    #5, aluminum intake
    #6, hot ignition [MSD, Petronix, etc]
    #7, more compression [shaved 70 heads, ajustable push rods]
    #8, total performance rebuild including all the above, plus more...
    If all that fails
    #9, 455 BB replacement!!!!!

    The 350 can be the basis for a fantastic street engine, but a SB can only go so far. There is also a serious lack of information out there on hot rodding buick 350's, and only a limited number of aftermarket parts producers... Unlike a SBC with a thousand proven combinations, and a million parts producers.

    The buick 350 is a long stroke motor, that produces killer low end torque. It loves to breath, but seems to like a little restriction in the exhaust, so a 3 inch system really is'nt nessecary, a 2.5 is pleanty.

    Rear gears can make a world of difference. I'v got a bone stock 69 GS-350 rust bucket with 4.30 gears, and it pulls harder than a lot of 455's I'v been in... But by 50 MPH, it's all over.

    If your going to replace it in a couple monts anyway, I'd just make sure it's all working properly, and go with the nitrous kit. If nothing else, you can re-sell that and get most of your money back after the swap.

    Good luck!
     
  9. NJBuickRacer

    NJBuickRacer I'd rather be racing...

    I know if I go inside that the cam bearings are worn, as my oil press@idle when hot is only about 12 PSI (and around 40@idle cold). I was going to pull the motor and freshen it up this weekend with a crank kit, new cam bearings and a hone and re-ring. I was kinda trying to get a feel for anything that I should do to this little Buick 350 while she's torn down (head port-matching,oil system mods,etc.) as I've built mostly Chevy and Olds performance motors for previous musclecars I've had and countless other stock rebuilds on almost every make of car. The last GS350 I had, I freshened the internals and put a mild cam in (I think it was a Comp but I don't remember) with a new timing cover from NAPA to get my oil pressure up as my old one was pretty scored up in the oil pump area. It had decent power but I definitely wanted more. I was going to get the heads I have here(already been freshened up with new valves, guides and seals) cut down to bump my compression a half point or so and do a quick port-match. Also, I might pick up the cheapest performance cam I can find (anyone have a used cam lol) and pop it in while all is disassembled.
     
  10. Racin Jason

    Racin Jason SIZE MATTERS!!!!

    Throttle in a bottle!!

    Hey Darryl,

    I noticed you have mentioned N.O.S. a couple of times in your last post. I hope you or someone else has the answer.

    I have been pondering using N.O.S. on my car and was curious if it is safe for stock '68 rods? I know they are not as strong as the '73 and newer rods. I am currently rebuilding the engine to '68 specs and will be a stock bottom end (crank ground .010) and a slightly bigger cam.

    I just do not want a nuclear disaster at the racetrack! :Dou:
     
  11. Darryl Roederer

    Darryl Roederer Life is good

    Jason-
    I nitroused the hell out of a 70 motor, with the stock 70 rods in it.
    I started with a 175 hp kit, but could get zero traction with the open stock rear end.

    I ended up with a 125 hp plate on the same engine, and put thousands of miles, and dozens of bottles of N2O on the motor, with no bad expirences. Maybe I just got lucky:Do No: .......

    What does the 350 in is RPM's. I learned the hard way. Somewhere around 8000, something went CRUNCH!!!

    Number 5 rod broke at the piston pin, came thru the block, and the oil pan... A couple years later, I nuked a very expensive 455 by over-reving it also... After that, I became a firm beliver in the MSD 6 and 7 AL,,,, L for LIMITER!!! Keep my motors set a few hundred R's below the nuke zone now.

    My personal opinion, go for it!!! Keep the R's under control, and no more than 125-150 hp on the nitrous, and you should be fine!!!
     
  12. Racin Jason

    Racin Jason SIZE MATTERS!!!!

    Nuke Proof??

    Thanks for the info Darryl. That helps out alot!!

    I have the Accel 300+ digital ignition I am trying this year. It has the internal rev limiter, I should be ok.

    You mentioned about 8000 rpm!?!?!?! I got scared at 5000 with my stock setup. The new cam I am putting in now (just got it yesterday--yippee) will go to 6000 with new springs etc... Will the n2o take you to higher rpm levels? Would you experience valve float, colapsed lifters, or anything weird like that? I don't know very much about n2o, but I want to learn alot. If there are rpm gains, how many will you gain without getting into trouble??

    Thanks again! :bglasses:
     
  13. Dennis Halladay

    Dennis Halladay Well-Known Member

    Don't plan to take the RPM higher with use of nitrous. The nice part of nitrous is the instant torque it provides. I always set the shift light back a couple hundred RPM when I was going to spray. RPM is the root of all evil in the Buicks, nitrous allows the big power without the RPM and the motor will rev through way quicker when under spray. If you normally shift when you see 5000 RPM the car will actually shift later maybe 5200, when useing nitrous this multiplies, shift when you see 5000 engine may see 5500. Back the RPM down when under nitrous until you slow down then bring it back up a little. Nitrous motors don't have to be time bombs, but you can definately turn them into one if you don't use your head. I was amazed at how fast the torque comes in when the button is pushed when I saw it on the dyno. The line on the graph looked like it hit a wall when nitrous was induced, the HP came up fast also but not as extreme. HP and torque started to level off at a lower RPM with nitrous than without. I would get good rod bolts and have the beams polished and shot peened and keep the RPM down.
     
  14. Racin Jason

    Racin Jason SIZE MATTERS!!!!

    Thanks for the info Dennis.

    I feel a bit more confident that I did not just build a gernade.
     
  15. ijzane

    ijzane Well-Known Member

    Ported heads??

    Before you go porting heads, what casting # are they? I'm willing to trade/buy/ whatever a set of unported heads for our stock elim car for a set we have that needs all new seats. NHRA allows only 75% seat replacement. And of course we aren't allowed to port them, yet.

    May have a mild cam available. Stock lift, reasonable duration as opposed to the large duration that we currently use.

    good luck
     
  16. NJBuickRacer

    NJBuickRacer I'd rather be racing...

    Re: Ported heads??

    I'll get the #s off them this week...this entire project just took a turn for the worse as I got laid off from work on Friday due to the big tech slump. It looks like I may have to sell everything now, I may have more parts than this if you're interested. Also, the heads that are on the car now are '73 vintage and I'll take the #s off them for you also. I think I'm just going to finish the partially assembled 455 that I have and include it in a package deal if anyone wants the whole package.
     
  17. buick462x2

    buick462x2 Member

    have a 350 30 over with 150 shot on it shifts at 6200
    72 buick custom 13.01 @ 103.98
     

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