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Thread: High tick over

  1. #11
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    Thanks again Roger, I've played with the 650 dp before, I was led up the "it needs more fuel" route as it was stuttering almost a feeling of lean at the top end and so bought the 770 street avenger. When I fitted it straight out the box the top end was great but driveability at the lower rev range was awful and it was drinking fuel!

    Therefore after much research I put the 650 dp back to basics and I'm keeping it at baseline level until timing is done. I'm running an electronic distributor which looks stock.

    I've played with the grub screw before but I needed to know where the secondaries needed to be as part of getting the carb back tostock, I'm sure I've set my timing to your numbers so checking it Tuesday will answer that!

    But have to say thank you again for your advice.

    Lee

  2. #12
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    Ok managed to get some time on the timing!!

    I’ve read on the 351c forums that the timing is what you said or some are at 10 static and 36 all in at 3000 rpm

    I’ve put mine to 10 static but at 3000 I’m at 45/46!! It was a bit difficult on my own but when I initially timed the new electronic dizzy which looks stock, I’m sure I remember advancing it through the vacuum hole!

    So before I start on the carb as the grub screws have arrived, am I right to slow the rate of advance on the dizzy?

    Btw the tickover is now at 850/900 rpms and it’s not driving to bad either.

    Cheers

  3. #13
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    May 2003
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    The all in advance is mechanical only so make sure the vacuum is disconnected (and plugged at the carb).

    45 is too much if it’s only mechanical, I’ve never heard of anyone running that much. If you have the vacuum attached then 45 is probably ok for a lightly loaded engine. When you are at WOT, the vacuum will be zero so that’s why the 36 is about the max you want, any more and you will be robbing bhp. At 45 mechanical you risk damaging the engine.

    what dizzy are you using? Adjusting through the vacuum will only be adjusting the amount of vacuum advance you have, not the mechanical which is controlled by the springs/ Bob weights and stops.
    Last edited by RogerKnill; 29-01-22 at 06:21 PM.
    Roger

    RamSC 351 Cleveland

    on the road 20 years- nearly finished

  4. #14
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    Cheers Roger this is all good and welcomed information, I’m going to try again whilst it’s sunny - I have to tune away from the house as everyone moans about their house shaking!!

  5. #15
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    cheshire
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    Hi Roger, sorry it's been a while but here's an update.

    Timing set 32 all in 3000 rpm. Mechanical only
    Transfer slots set
    Holley 770 street avenger vac secondary.
    Tick over was 1400 but ran awesome with crisp quick response when revved, a bit of a stumble around 1/2 throttle but still ran best it has.
    Purple spring in vac secondaries
    Pertronix flamethrower dizzy on springs it was supplied with.
    Had to back off the tick over screw, lost my transfer slot position and back off the timing to get tick down to 900
    Now it feels like it's lost it crisp quick throttle response

    Do I have too much carb but it did feel so much better accelerating but with high tick over!!



    What carb are you running?

    Lee
    .............never drive faster than your guardian angel.

    cobraclub.com/gallery/showgallery.php/cat/633 - this is the link to my build photo's you have to put w w w . h t t p : / / in front of it!!

  6. #16
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    Quote Originally Posted by 427jlc View Post

    Do I have too much carb but it did feel so much better accelerating but with high tick over!!


    Lee
    Quite possibly. I ran a Holley 600VS on my Pontiac 400 engine for years - pulled like a train. I then tried a new 670 Street Avenger and suffered idle / off idle issues that required some major fiddling.

    Some links - https://performanceimprovements.com/blogs/news/carb-size-matters-what-size-carburetor-do-i-need
    https://www.holley.com/blog/post/how_to_choose_your_next_holley_carburetor_/

    Steve Brown

    CRC Regional Rep - East Anglia

  7. #17
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    Cheers Steve, on the Cleveland forums the 750 vs or do seems to be the carb of choice, I was getting bore wash with the 650 dp and the engine ran strong on Sundays test run.
    It was just the DAMN tick over!
    to be honest Sundays test run ran the strongest and smoothest ever, little but of midrange work to do.

    The Ford diy pages say for the Cleveland;

    Ignition timing should be somewhere around 6 to 12 degrees BTDC at idle and total timing at 3,500 rpm at 34 to 36 degrees BTDC. This keeps things safe and minimizes the risk of detonation. You want the air/fuel mixture on the fat (rich) side to prevent detonation and a lean meltdown.

    So I may try as low as 6 btdc but how to I get to 34/36 all in? Think is 6btdc should get the revs down?

    It's just that when it's backed off revving the engine from idle doesn't feel snappy or sharp.

    Anyone's thoughts is appreciated I know I'm close with this carb it's just timing has never been my strong point.

    I've ordered a set of springs for the dizzy

    Lee
    .............never drive faster than your guardian angel.

    cobraclub.com/gallery/showgallery.php/cat/633 - this is the link to my build photo's you have to put w w w . h t t p : / / in front of it!!

  8. #18
    Join Date
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    Following a rolling road set up on my timing from standard was a good few degrees advanced from standard TDC. They used listening and anti pinking for detonation and back off a few degrees. They smoothed out the midrange and gained 25 lb torque !
    I am running a 600 Holley on 2v heads the AFR was spot on all the way through revs so I never ran out of airflow. I guess with a high lift cam and 4v heads you need lots of airflow . You might well be over carbed unless its stroked or 4v and high lift cam.
    John Desz

    Essex & Herts Area Rep. UKCC

    Crendon No5 S.A. 452Cu in, Ford Fe, Tremec TKO600,

    Dax 351 Cleveland T5 2.88 PL

    Events posted and meeting updates follow Face Book.

    https://www.facebook.com/groups/170236225077355

  9. #19
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    Dec 2007
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    cheshire
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    Cheers Jon,

    Interesting you run a 600, is it vac secondaries?

    Also I'm on 2v opens heads with a very mild cam, it's only a 268h.

    I may sell the 770 street avenger and 650 DP and buy a 670 street avenger if the stress levels keep rising!!

    I have a full holley jet kit so jetting down is not a problem.

    Thanks
    .............never drive faster than your guardian angel.

    cobraclub.com/gallery/showgallery.php/cat/633 - this is the link to my build photo's you have to put w w w . h t t p : / / in front of it!!

  10. #20
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    Jan 2006
    Location
    Chelmsford Essex
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    I am running the same cam 268H and Mallory VAC on secondaries with Partronix contactless. Its a very noticeable kick when the secondaries come.
    When I had it on the rolling road there was a noticeable dip at 3350 rpm but the timing adjustment was advanced and this smoothed out the dip.

    The torque is flat from 1800 - 4000 rpm 360 lb peak at 2000rpm. I have a rev limit of 5,250 rpm as you really don't need to rev it.

    My engine was built by Racing Heads in USA who port the heads and are well know on the drag strip and still in business.
    John Desz

    Essex & Herts Area Rep. UKCC

    Crendon No5 S.A. 452Cu in, Ford Fe, Tremec TKO600,

    Dax 351 Cleveland T5 2.88 PL

    Events posted and meeting updates follow Face Book.

    https://www.facebook.com/groups/170236225077355

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