434 timing..

[jsw444]

whats the best place to start......i always ran the 406 at 34 degrees just wondering if big cubes need different timing....

[gaz05]

What cylinders heads? comp?

[MasterSbilt_Racer]

It is totally head dependent.

[jsw444]

dont have alot of info on the motor.....should have that this week.....i know it has 18 degree heads and is 14 to 1 compression.......we ran it tonite at 34 degrees .....run a little warm.......got a little work to do...i will post the motor info as soon as i get it...thanks guys.....

[MasterSbilt_Racer]

Don't know which heads you have, but I doubt you want to go over 30 degrees on gas.

[jsw444]

not sure either ...waiting for info from builder......i know performance engineering up here in michigan did them.....as soon i know i will post......30 degrees ....wow that seems retarded ...lol the motor builder has 38 marked on the balancer.....

[perfconn]

18* needs 32*

[jsw444]

just got done chatting with a guy that is real good with motors...he said 32 as well...........kinda leaning towards that........thanks everybody....learn something everyday .......

[hpmaster]

My 18 degree Brodix 421 has currently 33 degrees of timing and we ran it at 36 degrees for 3 years and one freshing with no problems. We retarded the cam timing 3 degrees and dropped the ignition timing 3 degrees on the dyno last winter to improve torque and hp curves. I am too broke and cannot risk a good motor guessing on mixture, lash and timing. Dyno time is where all that needs to be figured out not on 4m. jmho.

[jsw444]

so you are saying that you gained hp's and torque with less timing?????

[hpmaster]

so you are saying that you gained hp's and torque with less timing?????

You can change the torque and horsepower curves with cam timing.Not really gaining it but making what you have in torque and HP more useable by having at a different point in the rpm range. Retarding cam timing can delay and smooth out the torque curve somewhat at lower RPMS and can make an engine more drivable. A longer stroke engine inherently produces more torque and if the torque curve is too peaky and or too early you can end up with a motor that just blows the tires off. The best way to look at it is like leveling a hill in your yard without adding dirt but move the hill to a different spot or change the slope. Dyno time, if your engine is prepared with an adjustable timing set with a way to easily access it can be a help in changing the curves and helping drivability. Trying different header designs, pipes and mufflers/antireversion chambers can also help as can using lash adjustments and jet changes. BUT a bad cam will never be a good cam no mater where you time it at. Dyno time is about $500.00 but if you are prepared you can learn alot.

[FlatTire]

HPmaster provided some good advice. We've never left the dyno with less power than we originially showed up with. ;-)

[jsw444]

32 degrees was the ticket...motor ran much better and was running around 200 degrees on the track.....thanks again guys....this site is overwhelmed with good info......thank you.......