Register now to get rid of these ads!

Puttin' Perfume on a Pig...307 Tech?!

Discussion in 'The Hokey Ass Message Board' started by Fat Hack, Feb 20, 2005.

  1. Tim
    Joined: Mar 2, 2001
    Posts: 17,098

    Tim
    Member
    from KCMO

    Probably took the crank and put it in a 350 block for a 327 and stuck "whatever" back in the 307 block and wondered why it rattled lol

    Because of the quench/ piston height issue you can't just use a 283 piston even though it's the same bore. However I have read of people using 400 connecting rods with 283 pistons and it balances out.

    Maybe one of us should call JE seems like the easiest way if Beaner is correct
     
  2. I've done a few 307s -
    *Pistons have been flat tops with valve reliefs *
    *about 0.025 in the hole
    *with steel shim gaskets
    * 76cc heads.
    And Perfect quench distance.

    The main reason was to drop NO emissions. NO is formed in the combustion chamber above a certain heat threshold. Dropping the compression prevents NO from forming.
     
    porknbeaner likes this.
  3. You can get 6" rods from a Ford 300" 6. That would move your piston .30 up the bore. Granted there is some machine work involved to make the Ford rods work and you would have to have two Ford 6s to rob but it is a solution. I would need to measure a 307 to tell for sure but it may put you over the top or pretty close to it. If you were within a couple of thousandths you could perhaps shave a forged piston.

    The 400 rod is shorter than the prior small block rods @ 5.565 instead of 5.700. The 400 rod would shove your piston .135 farther down the hole not make it closer to the deck. Closer to the deck is what you want.

    A set of JE pistons will run you in the neighborhood of 600-800 dollars, plan on the bigger number unless you can talk them into letting you run sticker on your car or you are a magazine guy who is willing to tout them for fun and profit. :D

    And after the fact they raised combustion temps and began running catalytic converters. LOL

    The problem arises from the fact that the engineers were not engine builders well that and the bean counters were involved. Anyone knows that you don't lower compression by shoving the piston farther down the hole you dish the piston to lower compression. :D

    Thanks for the number by the way, I have not measured one in quite q while and didn't recall the distance. ;) .025 would make running a 6" rod and a stock piston not work. But I'll bet you can buy 283 pistons with an adjusted pin to run a 6" rod. Maybe.
     
    Last edited: Sep 18, 2017
  4. Tim
    Joined: Mar 2, 2001
    Posts: 17,098

    Tim
    Member
    from KCMO

    Where did you source your pistons out of curiosity? A couple places have stock rebuild pistons avalible but they look to be even lower compression than the stock slugs
     
  5. Most rebuild pistons have a lower compression height to make up for added bore. When you increase your swept volume you increase your compression.
     
  6. All rebuilder Pistons have a low compression or pin height to compensate for the fact that you've decked the block. They are one step ahead of you saving the need for machining piston's tops and if you don't deck the block you're fucked. See how they help you. :D:eek:


    I absolute love a 307 build, but it's got to be the right candidate to start with. I love them because they are cheap and the dollar per HP ratio can not be beat provided the right candidate. My recipe is about $600 for 325 Hp.


    Once you need bore and oversized Pistons they are exactly the same cost as any other engine and the dollar per HP ratio plummets like a rock.

    I start with a decent short block that doesn't need machine work or Pistons. Most 307s have led an easy life and although running perfectly well were pulled just because they weren't something else.
     
  7. Tim
    Joined: Mar 2, 2001
    Posts: 17,098

    Tim
    Member
    from KCMO

    I like mine well enough, and every time we've had the heads off everything looks good but I'd be knocked over with a feather if I saw it made 325.
     
  8. It's easy peazy to get 1 Hp per cubic inch- that's 307. Trying just a little can get you 6% or 18 HP more.

    It is a small cube engine so velocity is very very important. Treefiddy rules don't apply. 305 HO heads & steel shim gaskets, smaller intake runners small primary tube headers, 8" long transition cone to 2" exhaust with 2-1/4 mufflers and tail pipes. 305 vortec heads work too but it's hard to get an intake that fits without big runners. Power pack heads are good to but they are down on compression from the 305 HO heads. 305 heads from trucks and Vans are pretty good but not as good as the HO heads. 1979 one year only aluminum 305 heads are really good if you can find them.

    A Bigger cam will make bigger peak numbers and a steeper curve but the average drops when the bottom end doesn't come up quick. That 262 cam makes a really nice curve that comes up quick and stays level. If you drive it a higher average is better than big peaks. The 262 made the highest average.
     
  9. Tim
    Joined: Mar 2, 2001
    Posts: 17,098

    Tim
    Member
    from KCMO

    That's pretty much what I've got, well the headers are on the shelf. Maybe I'll drive it over to a chassis dyno and see what this monster is making, It's geared pretty high so the seat of the pants dyno is a little iffy
     
  10. What intake ?
    What's the primary tube size?
    Collector size?
    What does the transition to exhaust pipe look like?
     
  11. Tim
    Joined: Mar 2, 2001
    Posts: 17,098

    Tim
    Member
    from KCMO

    This is what I've got to go on and then into duals. The short headers have a 1.5 primary and 2.5 collector. I'll run duals off the ends of the tubes
    IMG_9591.JPG
    Right now I'm running vette ram horns with 2.5 openings necked down to 2 1/4 exhaust.

    Intake is Ann edelbrock performer es - not 100% on the es but I'll scroll back and check
     
  12. Tim
    Joined: Mar 2, 2001
    Posts: 17,098

    Tim
    Member
    from KCMO

    Just checked page 6 it is a performer es manifold.

    I also think the heads have been surfaced before, running felpro gaskets I'm figuring compression around 9.5:1 maybe a little higher

    Power feels strong right around 2600 rpm and up
     
  13. Deuces
    Joined: Nov 3, 2009
    Posts: 23,758

    Deuces

    Can I still buy .030" over 10.25 cast pistons for a 327 dirt cheap and who carry's those?????
     
  14. Tim
    Joined: Mar 2, 2001
    Posts: 17,098

    Tim
    Member
    from KCMO

    I don’t know what this has to do with the topic of this thread. Or if those pistons are available for cheap. I’d say google is your best bet
     
  15. Deuces
    Joined: Nov 3, 2009
    Posts: 23,758

    Deuces

    Part of this thread also talks about using the 307 crank in a 350 block...
    Or, I could be wrong....
     
  16. I just had a brand new set of 3.875 bore Pistons in my hand for a 4.8. $150
    Wonder what rods would work ?
     
  17. indyjps
    Joined: Feb 21, 2007
    Posts: 5,377

    indyjps
    Member

    307's are good to go, got a bad rap with very bad heads, low compression and 2bbls.
    305 1.94 heads on a 307 is an almost free combo, pair it with a used dual plane and almost any mild cam and it will be a good driver combo.
     
  18. indyjps
    Joined: Feb 21, 2007
    Posts: 5,377

    indyjps
    Member

    4.8 pin ht is 1.324

    9.025 deck, 0.025 piston to deck, 3.25 stroke, 1.324 pin ht, gives a 6.05 rod.

    L99 262 v8 from mid 90's in caprices used a 5.94 rod stock, Ive always been interested if someone has used these. They arent the rod length you need for the combo above, but its interesting.
     
    Last edited: Nov 24, 2017
    31Vicky with a hemi likes this.
  19. dualquads
    Joined: Apr 9, 2012
    Posts: 86

    dualquads
    Member

    I was told many years ago that the 307 crank is the same casting as used in a large journal 327, I bought one a few years ago to use in a 350 block, you use it in combination with 350 / 327 rods and 327 pistons to make a 327, lot more good 350s in the UK than 327s .
    Kev
     
  20. I have a question about the 307. I bought a new short block. Put in the 54. Could not get any way shape are form chevy starter to work. Jerked the 307. Now I can't sell the block,because a starter will not work on it. How about the rotating assembly. Can I get. Anything for it.
     
    Last edited: Nov 27, 2017
  21. That doesn't sound right. Got the block casting # and a photo of where the starter goes? Sounds like a straight bolt starter on a large ring gear. JW
     
  22. You should post some pics of the problem and Some measurements.
    Are you saying you bought a "new 307 short block" ? If so Where did you get that?

    Your other thread might be a good place or here as well. I doubt it's a 307 problem,
     
    Last edited: Nov 28, 2017
  23. The block was in a guys garage for over 25 yrs. he bought from GM. I have a friend who had an auto electric shop. We used every possible way to make a starter work. Big and small flywheels. After a month of shims bolts and stuff I gave it up. 307 had a history of starter issues. Googled it several times. Numbers 3956618. 1968-79
     
  24. IMG_2055.JPG IMG_2056.JPG Here's the pistons coming out. Giving the rotating assembly to another old guy that will do something with it. Junking the block.
     
  25. In 1980 I bought a 72 nova with a wheezy 307 but the car was a factory 4 speed..Muncie M-21 with Hurst linkage. After about 6 months I swapped in a 327/350 cam, a Qjet on an aluminum intake and headers with dual exhaust. Really woke it up but with the small valve heads, it'd run outta power after about 5200 RPMs. Good news is I got 18 MPG on the hiway.
     
  26. Not sure why you won't measure and post some pics. Your measurements about the starter mounting boss can easily be compared to a SBC blue print.
    If every starter failed and shimming failed it must be a problem with the hole locations or boss height.

    http://67-72chevytrucks.com/vboard/showthread.php?t=280337
     
    Last edited: Dec 4, 2017
  27. I built a couple of SB Chevs with mount holes for only one starter type, cant remember what one....30+ years ago and im sure they were 307's. JW
     
  28. DBV
    Joined: Dec 28, 2017
    Posts: 2

    DBV

    I read through this post. I am looking for any and all info I can find on 307 builds. I have a nova only 283 block with a cast crank and forged rods, the current cam is the original cam and according to everything I have found, was used in the 195 & 220 hp 283 and 250 & 300hp 327, this is a low lift long duration cam, plans are to swap in a forge small journal 327 crank and 307 pistons, 062Vortec head from ‘99 5.7, these are suppose to work well with low lift long duration cam, eddy 2116 performer intake, Q-jet carb and headers, I have input all this info into the Dyno 5 sim software and get a max 440 hp, I don’t believe this so I am search for someone that has similar setup and if they know what numbers the are getting
     
    Last edited: Dec 29, 2017
  29. DDDenny
    Joined: Feb 6, 2015
    Posts: 19,144

    DDDenny
    Member
    from oregon

    Welcome to the HAMB.
    By "Nova only" 283 block are you meaning the 64-67 with the recessed oil filter?
    Regarding the info you found on that camshaft, what was your source, I can say unequivocally that the cam for the 325/350 HP 327's was NOT used in any other engine.
    I think that 440 hp figure is about a hundred hp higher than the combination is capable of.
     
  30. 56sedandelivery
    Joined: Nov 21, 2006
    Posts: 6,695

    56sedandelivery
    Member Emeritus

    I have a "nodular" iron 307 crank I took in as parts-in-a-trade; it had been fresh turned, then sat in a plastic bag in the garage, and now has rust spotting that comes off with a finger wipe. FREE to anyone who pays the shipping or comes and gets it. There you go! I am Butch/56sedandelivery.
     

Share This Page

Register now to get rid of these ads!

Archive

Copyright © 1995-2021 The Jalopy Journal: Steal our stuff, we'll kick your teeth in. Terms of Service. Privacy Policy.

Atomic Industry
Forum software by XenForo™ ©2010-2014 XenForo Ltd.