be verrrry careful

[billfisher]

ok so i do a lot of things with these mods, just for fun. just routine stuff like pull cams and tinker. don't ever lose your respect for the dreaded timing jump.


when i pull the cam gears i make black paint marks on the crank and cam gears.


always... except this time. i decided i was just going to skip it one tooth so there was no need to make match marks. i wasn't even pulling a gear off, just removing the tensioner and jumping the cam one tooth.

then it happened. when i was thinking about something else and not watching the lower gear it jumped 2 teeth. i felt it but didn't see it. i didn't know which way it jumped. and to make matters worse i was a few degrees from the top making the planned jump.

1 uper tooth = ~8.5*
1 lower tooth = ~17*

one thing about these interference motors is that retarding a few teeth is ok, but advancing a few teeth is disaster. losing the cam not in 'neutral' is disaster. luckily i had the cams in a safe position. so i jumped the lower a couple of teeth and started the LONG process of getting the timing links in place turning by hand a 9.8:1, 330 cu.in. motor. bruised palms. i felt no mechanical stoppages.

 

[billfisher]

so... as some of you know it takes many many turns to get the lower link to finally match the crank mark. so i risked the starter. it turns out the i had the timing back to factory by luck. so anyway it is retarded one tooth as planned and i have started the motor to be sure i have no bent valves. could have been very expenjsive with 12 valves to replace on each head.

i did the driver's side head with no issues. and it took a half hour as apposed to a whole day.

 

[Stan Weiss]

I do not remember do you have stock cams? OK so what have you felt driving the car after you retarded the cams 8 plus degrees? What is the low RPM and high RPM differences?

 

[billfisher]

it idles the same. i haven't driven it yet. i have a hockey game to go to. go preds.


i will let you know tomorrow. remember this has vct and the default position is 9 degrees advanced. so really i am changing to straight up. later.

 

[billfisher]

ok, here is the answer.


the idle is a little different. it lopes a little. it is also quieter at idle. not smoother, but quieter.

to describe the power i need to describe it before the change.

if you look at my dyno graph in the dyno section of this forum you will notice the sudden peak at 3600 then a gradual loss until 5000 where it quits. that is typical for the stock 16" runner intake. no matter what the bolt-on are the level will change but not the form. the highest truck based intake power level id 345rwtq and 280rwhp, that's in a 4x4 with around 25-30% losses. they all peak at 3650 and hp at 5100. they are 75mm throttle body limited also.


forward to me. i have eliminated the one thing no bolt on could overcome. 9 degrees advance of the cams.


ok back to the perceived power. when i ran this the first time it 'felt' like it wanted to rev to 6000. that's obviously not the case at all. it only really wanted say 4700. the torque drops so slowly it is impossible to detect without a dyno.

so i have a dyno and it quits above 4500.

now i can tell you it hits the rev limiter i have set to 5500 hard as hell. i doubt it makes power there, but it feels like it does in a way it never did before.


the motor runs better in every way it can. smoother, quieter and makes more perceived power than before. i know it does from dyno sims. i have a deadline of saturday morning to race, so i can't put the 11" runner intake with lightning throttle body on it by then. i did change the linkage on the TB today, but no more progress. i have to do the gears tomorrow. later .

 

[billfisher]

i'm just going to illustrate. not that anyone cares.

forget the number, and labels, but rather notice the power curve shapes and the way runner length shapes power. you can't completely overcome runner tuning.


here is what a 16" stock truck runner does to a mild bolt on 5.4 3v. notice the curve is shaped nearly identical to my dyno.

here is the same motor with the cams retarded 1 tooth. note the tiny shift in HP but little gains.

now note the effects of an 11" runner with stock timing. note that it is really a mismatch, neither torque or HP is great.

lastly here is my final setup. 11" runners with 0 cam timing. this is with a 75mm throttle body.


i will run 850+ cfm where the 75 will only flow ~733. so more HP to be added when i do that.

the real goal for me is to compete with Mach1 power ane ET's at the track. saturday i will post timeslips to support the 16" 0 degrees sim numbers.


LOOK AT THE PEAK RPM'S NOT THE NUMBERS. THIS IS ABOUT SHAPE NOT NUMBERS.

 

[billfisher]

BTW all of those sims are with stock intake 75mm flow and full stock exhaust. stock cams. etc.

 

[Stan Weiss]

It will be interesting to see how it does at the track.

 

[01Steeda]

thats pretty intresting bill, how many intakes have you played with so far... and when are you swapping to the 11"?

 

[billfisher]

i have 2 intakes. one stock the other has been i various stages of mods.

i'm going to swap to short runner soon. i am pretty burnt out from a week of too many projects.


the track is the final judge. i personally suspect that the long runner shortened to 14" with fully ported inlet wil perform better at these rpm levels. bigger cams and forgings with revving to 6500 is probably the only way to extract full power out of the 11" runners. Al says 7" runners are the best for 5.4. i doubt i will ever push the rpm's that far. but you never know.


one suprising thing about 3v or 4v 5.4 is the torque. 330 cubes exceed 400 flywheel torque is satisfying. of course if you look at Mach1's there are plenty with 340 rwtq with just bolt-ons.

 

[billfisher]

ok here is the verdict.



i ran

9.15 @ 77
60' 2.10

last year
9.35 @ 82
60' 2.0


so what does it mean you say? i lost enough torque from the cam phasing and removing the 'x' pipe and ....

lost HP from a mismatched 16" runner intake to offset the gears and suspensikon, which, by the way did not spin even on my last redlight run with ~wot at the line.


no ET or 60's for the redlight run. but it was by far the best leave on the line.

last year i stomped it from an idle to get the 2.0's 60'. it doesn't work that way at all this year. i have to get all of the stall i can without pushing the fronts.


so next time out i will try better running. i only had 3 practice runs. 10.0 @ 71, 9.35 @ 75 and 9.15 @ 77. i fooled with the fuel and got it wrong. 44psi is the magic number. i tried 52(9.35) and 40(10.0).


for comparison at this track. a stock 05 auto runs 9.4. a near stock Mach1 runs 8.7. a full bolt on Mach1 runs 8.29. my car ran identical to a 95 Z28. so that gives you the idea of the torque and HP losses.


if i had the time to get the short runner ready, maybe the results would have been different,. or maybe not. this is all new stuff trying to figure out what a 5.4 3v likes. i know one thing a Mach1 is bad-ass.

 

[Stan Weiss]

You ran .1 slower to 60 foot and ran than ran .2 quicker in the 1/8. which means you ran .3 quicker from 60 foot the 1/8. Sound good to me.

 

[billfisher]

i have a lot fo figuring to do before i make any other changes. i really haven't looked at it that way. i guess what i really need is a higher stall converter. i went conservative on the gears, thinking to let torque get my 60'. well i don't have as much torque as i did. so 3.90's are probably too tall. i may switch to 4.11 or 4.30.