ok i did a vaccuum test, no leaks-i blew MAP gas all around the intake no idle isseues, instead of propane if that matters. my preload is 3/4 turn past zero lash(is that to much preload?) the cams at +4, i dont want to retard it because my midrange sux as it is. i have HS rockers-could they be causing HP loss or TQ loss due to there heavier weight than stock? is something wrong with my setup somewhere? i dont have a pulley installed yet but i do have one, but wanted the most out of the car before i installed it. im gonna tear the exhaust apart to see if my cats are blocked up, but i doubt it. i think this car is a hater

 

might be in the cats,are they the high flow metalic substraight type?

 

random tech metal matrix high flow cats

 

Pdd, you have Harland Sharp rockers? Aren't those non adjustables? If so then:
1- You just need to trq them to 22lbs past 0 lash
2- Your preload is determined by your p-rods, so I would check if they aren't too tall. (did you do a swipe test?)

 

what is a swip test? they are non adjustable HS rockers.

 

Since they are non adjustables then the turn method doesn't apply. They need to be trqued down with an accurate trq wrench to 22ftlbs past the point where you can't twist the p-rod by finger.

The swipe (wipe) test:
Remove rockers on cylinder 1.
With a marker blacken the flat top part of the int and exh valves
reassemble everything
disconnect injectors and coil packs
Crank motor over 2/3 times for a few complete revolutions at a time
take the rockers off cylinder 1 again
read the mark left on the top of the valve.
1- if it is well centered, then your geometry is right,
2- if the mark is closer to your rockers, your rocker stands need shimming
3- if the mark is further to the outside of the head your rocker stands need shaving
http://www.holley.com/HiOctn/TechSer...ECVTTech1.html

Once you have the wipe centered, then you need to measure correct preload on your lifters to determine if you have the right length p-rod.
on stock lifters, it is between .030>.060
Less than that too short, more than that too long.

 

THANKS. I'll try the swip test when i get a chance

 

I edited my post since the wipe method as I decribed before is for flat tappet (sorry SBC flashback).
That method is true on stud type rockers in LSx motors (like Comp Magnum)
In LSx motors who have rocker stands and hydraulic tappets the wipe method adjusts geometry and preload, while p-rod length adjusts only preload.
So first get your geometry right, then adjust preload via pushrod length.
That is the difficulty in aftermarket rocker set ups.

 

i have a qustion about teh torque of the rockers, i torqued my rockers down to 22 or 24 ft lbs, on the write up it said to just torque them. should i pull off the vavle covers and do it like said, once the pushrod stops twisting? ive never read that before

 

i used this write up which uses the turn method
http://www.ls1howto.com/index.php?article=21
so preatorz-should i not use that method?

 

i used the cam install guide on there with the stock rockers and they said just torque them, id like to know if i did it right

 

Every aftermarket has their own little tricks, for non adjustables (stock or not) it is straight forward. Tighten bolt gently untill you cannot twist the p-rod by hand (no need for it to be forceful). Once you reach that stage it is 22ftlbs with an accurate trq wrench.
Personaly I like to bring both valves at same height "compression height" (not necessary, but that is me)
After that you need to check preload on lifter just to make sure you have the correct p-rod length.

Preload measurement:

I normaly prime the motor at this time with coil pacs and pump still disengaged and fuel line disconected (use container for any remneants in fuel line), butwith covers on (not to make a mess).

Once I have done 2>3 cranks with a few full revolutions and i see oil pressure for a few seconds, then I remove covers:

Hand rotate the engine in its normal direction of rotation until both valves are closed. You are on the compression cycle for that cylinder. (At this position the valve springs are at their least amount of tension making the job a little easier to do.)

Wait a few minutes, allowing the lifters to bleed down. Now, lay a rigid straight edge across the cylinder head, supporting it on the surface of the head where the valve cover gasket would go. Using a metal scribe and the straightedge, carefully scribe a line on both pushrods. Now slowly remove the torque from all valve train bolts, removing any pressure from the pushrods. Wait a few minutes for the pushrod seat in the hydraulic lifter to move back to the neutral position. Carefully scribe a new line on both pushrods.

Measure the distance between the two scribe marks, it represents the amount of lifter preload. If the lines are .030” to .060” apart you have proper lifter preload. If the lines are the same or less than .020” apart you have no or insufficient preload.

Hope this makes sense.

 

well most of my pushrods were sticking up so getting them to touch and then torque would have been the same. do you think this is something that needs to be redone? id hate to take it appart but i would hate it to be wrong, when you did yours what was the TOTAL torque value you ended up at in the end?

 

22 ftlbs. If you do not do 0 lash on non adjustables (especially stock non shaft), you might bolt them on crooked as the rocker will twist. Not really an issue with shaft non adjustables but that way you make sure you center the p-rods properly (both in lifter cups and rocker end.

 

this sounds more complicated that it needs to be. all you have to do is torque the rocker bolts to 22ft/lbs. all you have to do is make sure the rocker tip is straight on the end of the valve. do them all at one time, then turn the motor over a couple of times and re-torque them just in case. that's how i did it on my 402........... 430+ ft/lbs of torque at the wheels would have flushed out a problem. over 1,500 miles on the motor. plenty of racing and spirited driving. everything's staying put.

 

Checking your preload and geometry might seem "complicated" but that is why everyone wonders why is a sponsor making 480 rwhp with the same package as you and you're only at 450 !/? (exemple)

These are the nitty grity areas that reduce your valvetrain noise, insures correct geometry for long life, and of course finds the missing HP's.

 

when i did mine i torqued them, spun teh motor a few times and rechecked it, so all should be good. i guess we will see if im one of you examples when i dyno lol

 

Guys,
degreing cam, correct rocker height, proper preload, tight quench, matching H/C, proper tuning, will yield more power than just slapping it all together.
Ask anyone with motor building experience.

I got 404rwhp/383rwtrq from a cam only + bolt ons on an A4, 3200 stall and 3.73 rear.
Want to know size of cam? 224/220, .581/.581 116lsa +0

Combo and paying attention to detail goes a long way.

 

predator, you know your stuff it seems so can you answer some things for me.

degreing a cam, if you are not advancing it and just regular dot to dot install this isnt needed correct?

rocker height, is that what we have been talking about? f13 cam and afr heads, allan knew about the set up and i got the whole kit from him, stock length pushrods on gm mls gaskets.

preload is what we were talking about right?

and can you explain quench more to us?

if you can answer these things maybe it will help out more of us with power issues with cam/heads (not saying i have one but i dont like to leave out detail) i like to get it right the first time but this is the first i have read this stuff in my last year searching for cam install tips and what not. thanks man, for all the info

 

Actualy, while a lot of people just do that (install dot to dot), they are blindly putting thier faith that the cam is the right one, that it is ground correctly and most important that it is indeed dot to dot and not off by a tooth or so. Degreeing the cam will net you all these info and confirm your installation is correct. (besides the ability to measure advance and retard)

Rocker height with either aftermarket rockers, heads or both, needs to be set correctly to obtain a correct geometry. This is important for correct lifter preload and to minimise wear and tear on valves, rockers, valve gides etc...
Once correct geometry is achieved, then you move to measure and obtain correct preload. Rocker height is checked with a "wipe test"

Lifter preload is one of the most important parameter to set correctly. Too much and it will lead to loss of power and eventualy lifter failure. With non adjustable rockers (stock or aftermarket), it is set by using correct p-rod length while staying within the lifter preload specs.
Quench or squish is the distance between your piston and head deck. The tighter the quench ie: .030>.038, the better flame travel and efficiency of burn is achieved. Tighter quenches also reduce detonation. For the street I like to stay around .035>.040 as carbon will build up and reduce tolerances over time.
Tight quench is achieved by measuring your piston to block deck distance (it will vary between motors) ~ stock blocks are .005>.008 and using a thin gasket such as .040, .042, .045 gaskets.
Let us say that you piston is .007" out of the bore, so .040 gasket - .007 = .033 quench.

There is a whole buch of methods and applications to make more power. One often ignored is the weight of the moving valvetrain in the valve assembly, called effective moving mass of valve assembly.
So lighter valves, with lighter springs (like 918), titanium retainers will add extra horses to your set up. Of course those have to fall within the necessary requirements of the cam you are running.
That is why bigger isn't always better and it has been proven that a cam such as 224/228 will make as much as 480+ rwhp on stock cubes with the right matching combo.
Unfortunately we are not all wizards and we try our best, but as I always say, "If it is done once, it can always be duplicated"
Bottom line, a sloppy job is never effective, research and patience, also $$$ will net some amazing setups on our glorious (yet relatively simple) LSx motors.