327 cqm choices

Discussion in 'Engine Topic' started by Its_not_a_transam, Mar 25, 2019.

  1. Its_not_a_transam

    Its_not_a_transam Member

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    I had done a similar project i had built a 355. Flat tops. Xe262 cam. Air gap. 1 3/4 long tube hedmans. I was running a set of ported 492 humps. Shim gaskets. 3.23 rear end. 4 spd. It was very torquey down low and revved to 5800 or so. I found it was always in the power band at hwy speed. Made it somewhat difficult to drive smoothly. But passibg was a breeze. I switched it up for a set of proheader 64 cc heads. 2.05 valve. 195 cc runner. They were listed at 235 cfm if im correct. It revved to 6500. And was very snappy responce wise but it took all that lowend torque and moved it up in the rpm range. Car is 3750 lbs. On the hwy i will say ot was smooth and very tame but revved to 6500 very quickly and was nasty 3500 and up.. Engine seemed less temperamental in good and bad ways. The camelhumps were better around town and mid range..which is what i do most Maybe due to port velocity? I swapped out to 3.42s and it still seemed the same. We all know the vortec love. But i hate the added machining costs. The valve covers. The different intake cost. The crack happiness. Next is LS.
     
  2. Its_not_a_transam

    Its_not_a_transam Member

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    First motor ran 13.36 at 106. Sea level. 1.96 60 ft. Shifting at 5500. Never got a chance to run the same motor with the aluminum heads so just a butt dyno. Also swapped to an xe268 and 1.6 roller rockers. And a holley 650 in place of the old 600.
     
  3. jeff swisher

    jeff swisher Veteran Member

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    I ran the 280H often but many times I have it ground on a 108 or 106LSA.
    280H 110LSA in a 357" 3300lb Nova 456 gear and TH 350 converter stalled to 2200-2400 Do not know the compression but 450 casting small valve 305 heads from 1978, 1.72-1.50 valves.
    Ported and backcut. Runing a tunnel-ram and 2 600 edelbrocks it went 12.51 at 111 mph.
    Shifting at 6700rpm.
    I have the same cam in my 350" 3575 lb and it pulls hard to 7000 rpm.
    I had that cam in a 327" flat top with low compression like 9.2 and it was a turd below 4000 and was still turdish up top.
    I feel an earlier closing intake valve would really help in the lower compression deal.
    I feel a 268H on a 106LSA would be worlds better or even the 110LSA
     
    Its_not_a_transam likes this.
  4. Cardinal

    Cardinal Veteran Member Lifetime Gold Member

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    When it comes to cams and carburetors, less is usually more (powet) ESPECIALLY when it comes to low compression motors.
     
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  5. 1980RS

    1980RS Veteran Member

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    Huh, that's fuuny. Someone forgot to tell my super low compression 461 that. Every small cfm carburetor ran slower than the 850 mighty Demon.
     
  6. jeff swisher

    jeff swisher Veteran Member

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    You are feeding 461".
    Every big cube engine i played with kept going quicker and faster each time I stuck more cfm to it.
    Only engine I ever messed with that did not respond to a larger carb was a .060" over 327"
    Had a crower # 207 camshaft On a 108LSA I think it was around 228 or234@ .050 and .500-510" lift.
    Wish i had seen the specs.. a cam shop ground it and said run it with solids or hydraulics.
    I chose anti pump ups.
    The RPM intake was out for about a year and I was running them and used it on that engine and a little old 450 cfm carb was the king on that little engine.
    I tried a Q jet and 600 and 750 AFB carbs.. no other Holleys as I did not have any then.
    I tried all kinds of jetting and timing curves but that 450 from the mid 1980's era was the stuff for that car.

    3.08 gear 67 camaro 4 speed and it ran 13.8 ET. Used first and second gear only.
    I think it was around 1990 or 1992 when this happened.
    Traction was a huge issue.

    It had 461 heads on it.
    This was my cousins car and he was running 13.8 with a 100 or 125HP hit of nitrous and said it was fast.
    Yea right up to the time i beat him with a skinny tire 388 stroker Elcamino 225-70-15 tires.
    3840 lbs TH 350 and 3.08 gear That was a FIL vehicle I built.
    Next thing I know cousin is over with his 327 in the bed of his truck wanting it built.
    It had an earson 224 @ .050 and .447" lift with the old Torquer intake and NOT any port work to the 461 heads.

    After a cam, intake and head port it ran the same ET as the Nitrous passes.

    I still do not like small cube after building many 350's and a couple larger SBC engines.
    I got used to the TQ.
    To make the little engine keep up you need to toss more compression to it and step up the cam grind a tick.
    I found the same to be true of the 355 vs the 383.
    9.0 compression and 224 @ .050 cam in a 383 with ported old iron heads will run just about the same as a 10.5 compression 234@ .050 355" with same heads.
    Maybe the heads were limiting the 383 potential.
    One of the fastest street cars I rode in was a 283.
    I have no idea what was in it and he was not talking. But 8000 rpm shifts and second gear wheelies in an old 56 chevy was proof that what is in the inside counts.
    That engine looked slow with the factory valve covers and iron triangle heads.
     
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  7. Its_not_a_transam

    Its_not_a_transam Member

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    The c1h270 s cam apparently is 270/216, 110/lobe seperation.454" lift. I figure its probably a good cam to stick with and its already in there. Maybe throw a 1.6 rocker on it. Currently gonna run a comp cams1.52 magnum. Will have hooker 1-5/8 long tubes into 2.5 with an x pipe. 4 speed close ratio t10. 3.23 rear. Car is stripped to 3100 lbs. With a warmed over smog motor it was snappy. The 327 came to me as a "rebuilt 350" from craigslist as a garage cleanup on a house a guy bought .60 over. Trw forged pistons. H beamnrods . true double roller. Z28 aluminum intake. Fully built 461 heads (screw in studs ,guideplates) well it turns out to be a large journal 327. Im a 150 bucks into the whole shebang.
     
  8. Its_not_a_transam

    Its_not_a_transam Member

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    Took mine to the track last night with 12 degrees of timing in it. Could not get a launch at all. Horrendous 2.50 to 2.70 60 fts. Couldnt in 8 passes find a sweet spot rpm wise. Was spinning through 2nd. Through the traps 5500 in 3rd gear. Mph 102 -103 mph. Times were so slow i took my buddy with me. Ran faster et. 103.5
     
  9. jeff swisher

    jeff swisher Veteran Member

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    Sounds like you have some good reason to find tires that will stick now.
    Nothing wrong with 103 MPH
     
  10. Its_not_a_transam

    Its_not_a_transam Member

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    Went 101. 102 103 etc. With tuning and a good 60 ft i see 105 or 106. Was shifting at 6000 but tried 5500 and gained mph. Should be fun.
     

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