Chevy 350 headers on Buick 350?

Discussion in 'Small Block Tech' started by bino_5150, Oct 19, 2006.

  1. bino_5150

    bino_5150 Slab Rider

    Just curious... will Chevy 350 headers bolt up to a buick 350?

    if not, whats different?
     
  2. bignastyGS

    bignastyGS Maggot pilot

    They are totally different..The Chevy headers mount almost horizontally compared to the Buick. They are not even close...Sorry
     
  3. bino_5150

    bino_5150 Slab Rider

    ok, right as you posted, I was looking at side by side pics... I see what you are talking about...

    But as far as the ports are concerned, they are spaced correctly, right? Will the flanges bolt up to the Buick block? Because I can get Chevy block hugger headers for like $70 a set... I can cut and modify them. If the flanges bolt up, it would be worth it just to buy them to cut the flanges off, because thats WAAAAYYY cheaper than places like TA have the flanges listed...

    I don't mind a little modification... I am just curious as to what is the same and what's not... I had to make custom turbo manifolds for both my Probe, and for my friends MR2 when we swapped a turbo 3.4 v6 in it... I know a place that sells header builder kits with all of the mandrel bent pipe for like $60...

    Either way it goes, I still make out cheaper than buying headers... TA is one of the only places I found that has Buick 350 headers (I'm sure many other places do also), but it tells you real big in their catalog that the 350 headers DO NOT fit in the LeSabre; you have to cut and modify the pipes anyway... AFTER you just payed $400 for a set of headers...

    If the chevy flange works, $70 will get me the usable flange and collectors from the Chevy headers, and some useable pipe. Another $60 gets me the header builder kit with the rest of the pipe and all the mandrel bends I could possibly need...

    $130 = set of Buick 350 headers that fit perfectly on my LeSabre.

    If the Chevy flange doesn't bolt up, then I gotta come off the extra money for the Buick flange from TA, and still build custom-fit headers in the $200 range...
     
  4. 70aqua_custom

    70aqua_custom Well-Known Member

    The spacing is right but no, it will not bolt up. If you made your own flange you could possibly use the chevy pipes. That is if they clear everything. The SBC ports are quite a bit smaller.

    Pic is a 350 SBB header with a 350 SBC gasket on top.
     

    Attached Files:

  5. bino_5150

    bino_5150 Slab Rider

    ok, so then that part is settled... I saw earlier that TA Performance sells the flanges, I belive, for $140 plus shipping (but don't quote me on that price...)

    I can most likely go to the machine shop with a gasket and get some flanges made quite a bit cheaper than that.

    I think hacking off the flange and part of the bend on the chevy block huggers, it would only take a few inches of pipe and some minor modifications to make a set of Buick 350 blockhugger headers that would fir into the LeSabre and other bodystyles that the aftermarket headers don't fit...

    I don't see any reason why this wouldn't work... I think that this will be my next project...
     
  6. Justa350

    Justa350 I'm BACK!

    I've seen the flanges for SBB for $70 a pair on ebay. They aren't always available but if you have time to wait that would probably be your best deal. Pick up a cheap set of SBC block huggers from Summit and cut and weld! I think you could pull it off. :)
     
  7. GSXMEN

    GSXMEN Got Jesus?

    It's nice to see that the port spacing is so similar. That should give some easier options with various engine swaps. :TU:
     
  8. bino_5150

    bino_5150 Slab Rider

    yeah, this would be one of the easier manifolds that I've had to design... would anyone be interested in a set? I plan on playing with a couple different designs, but when its all said and done, I will only need one set. It would be nice to see a dyno or something, but I won't hold my breath...

    Once I get the basic design down and get a completed block hugger set, I want to make another set and start playing with the collector design and primary runner length.

    On smaller 4 cyl imports, optimal design usually comes from 4-2-1 style headers, although all of the headers that I've seen for the v8's use a 4 into 1 design. I'm wondering if there isn't some gains to be made from a 4-2-1 style design, seeing as how each cylinder bank is essentially a 4 cyl engine, especially if you are running duals. On smaller, high reving engines at least, the 4-2-1 design seems to be better at scavenging the cylinders.

    The 4 into 1 design is good for top end power, where as the 4-2-1 design is good for optimal performance across the rpm range.

    Most people tend to go with equal length primaries, however, on my 2.7 v6 PGT, unequal pipes make the most power. It also has an odd number of cylinders in each bank, also though.

    The ultimate goal, however, is a nice set of low-budget headers that will fit on the LeSabre and other body styles that aren't supported by other aftermarket manufacturers. Just because it isn't a drag car doesn't mean it can't have a lil kick...

    One thing I've learned... if you want an aftermarket, start fabricating.


    Here's some interesting quotes as far as that goes:
    One issue worth noting before having a look at the headers below is the ingition firing sequence. Since the D-series ignition firing sequence is 1, 3, 4, 2 (meaning cylinder 1 fires first, then cylinder 3, then cylinder 4, and finally cylinder 2), the smoothest exhaust gas flow will be attained by joining the 1and 4 cylinders and the 2 and 3 cylinders. The concept is to keep the exhaust gases flowing by not having two pulses enter the collector at the same time, which would cause excessive back pressure. This is called non-sequential pairing, and most of the D-series headers below apply this design concept. However, sequential pairing does allow for a broader powerband and better acceleration properties by pairing the energy from adjacent firing cylinders (ie. pairing 1-3 and 4-2). Given these different results, it is not suprising to see non-sequential pairing used for street headers that have longevity, well-rounded performance and ground clearance in mind, while a race header will benefit more from sequential pairing that harnesses the energy of adjacent pulses to create greater velocity and maximum power output.

    and this:
    The non-sequentially paired header design can do well if designed properly. Honda pairs them that way and that's probably one of the reasons all the aftermarket stuff is built that way. Yolu can get away with shorter primaries with a non-sequential 4-2-1 header where you can't as much with a sequentially paired 4-2-1. Sequentially paired 4-2-1s like primaries almost as long as traditional 4-1s and are therefore more difficult to build and likely to have ground clearance issues.

    Headers are designed for street or race and most street headers are far from optimized. If you look at almost any aftermarket USDM header company, their offerings for the Honda/Acura cars are non-sequential 4-2-1 headers, for most 1.6 civics and maybe even some of the 1.5s up to 2.3 Prelude engines all use 1-5/8'' primaries and 1-3/4" secondaries. Why? I'd say it's not for performance but $. They can buy more tubing of one size and get a better price for it, tooling is less costlky, coating costs are less, etc.


    I think some nice non-sequential paired headers would be nice on my LeSabre :TU:
     
  9. 87GN@Tahoe

    87GN@Tahoe Well-Known Member

    take those block-huggers and flip them upside down and send me some pictures :Brow:
     
  10. bino_5150

    bino_5150 Slab Rider

    yeah, thats the next big project. I think it will be fairly easy. I'll be sure to take a bunch of pics to post up.
     
  11. bob k. mando

    bob k. mando Guest

    however, on my 2.7 v6 PGT

    hmm. you do a stroke job on that?
     
  12. bino_5150

    bino_5150 Slab Rider

    go 60 over on the block, with some ford 302 to 347 forged I-beam stroker rods with a 2.1" chevy journal, and nissan 300Z pistons.

    This will also give you a slightly higher static compression, from 9.2:1 on your DE to around 9.5:1, maybe a bit more after you deck the heads (.050 to .060) and the block. 88 bore flat top pistons will get you more towards the 11.5:1/12:1 area. You will need a .1" copper head gasket, because the stock one is not thick enough, and you don't want valve interferance.

    You can use RSX pistons also, which are a bit more expensive, but will yeild a ZE-like 10:1 static compression.

    Also, all of these combinations weighs less than stock, and taking weight off the rotating mass will make your KL even more revvy...

    Your motor will now also be bulletproof to well over 550hp if you choose to boost and/or spray.

    If you build a ZE instead of a DE, All you will need is a good set of race cams and an MX3 flywheel, and you will be raising all hell on the circle track, and none of it will be noticable just by looking. by the way, if you do build a ZE, keep your DE valve springs...
     
  13. bob k. mando

    bob k. mando Guest

    my old man says "how bout using an Acura rod ... they're TI. plus a smaller big end so you can stroke the engine a little at the same time" :Brow:

    no, seriously, that's some cool stuff there. and to think, i've got an extra KLDE sitting around here that needs rebuilding. :3gears:
     
  14. bino_5150

    bino_5150 Slab Rider

    to the best of my knowledge, acura rods will not work inside the KL engine... not without some serious modifications, anyway, and not on the stock crank.

    the forged 347 stroker I-beam rods would be your best bet inside the KL. Like I said, you're golden to way over 500hp. The H-beam rods weigh more and require slight modification to the piston skirt to clear, but you wouldn't need them anyway unless you planned on hitting the 800hp mark on a KL...

    The best part of all this is no one will notice on the circle track, right? :TU:

    ~~~~~~

    As far as the headers go, I am ordering the Chevy block huggers, and I will modify them to work. I'll be sure to take a lot of pics for those interested, and I can probably make a couple extra sets if someone really needs some. Like I said, as far as I've seen, no one offers a set of Buick 350 headers that will bolt up to the LeSabre chassis. Hopefully we can change that...

    To Justa350 and anyone paying attenion, if you happen to come across a set of Buick flanges at a reasonable price, please shoot me a pm...

    I'll keep everyone posted.
     
  15. Skylark350

    Skylark350 Well-Known Member

    Bino - I'll take a set of those headers you're offering. My son has headers on his X-mas list already, but I can't believe how expensive they are! How much you want for a set?

    Is there really no cheaper alternative that will fit?

    1970 Skylark 350-4.
     
  16. GSXMEN

    GSXMEN Got Jesus?

    Headers by Ed has both 1 5/8" and 1 3/4" setups for the Buick 350".

    They're not cheap though.......about $130 for the flanges.

    If there was enough interest, I have a friend at a machine/fab shop that could flame cut a bunch of flanges. I could bring my old headers over for him to copy from.
     
  17. GSXMEN

    GSXMEN Got Jesus?

    BTW.....TA Performance also sells flanges for the Buick 350". They have the same sizes as above - no idea on price since their pricelist doesn't seem to work.
     
  18. Skylark350

    Skylark350 Well-Known Member

    I'll keep an eye out for flanges as well. Thanks for doing this, even if it's just the specs on how to build your own.
     
  19. 10sec 455

    10sec 455 Well-Known Member

    It would be like wearing your underwear for a shirt.
     
  20. rchandler

    rchandler so mote it be

    ta flange kit $136.00 comes with bolts and gaskets, also has stub tubes coming out of the flanges to ease fab time they are on page 119 of the new catalog
     

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