Grey Motor Rocker Adjustment

[TorqueFC]

as  iwas saying we have tried everything that you guys have said!!!! that is why i suggested about having the lifter up. anyway i guess somehow we will work it out

[Dr_Terry]

Hi Guys.

Everything that gp & RET & others have said is basically correct, you never adjust tappet clearance with the valve open.

Let's start at the beginning. If I understand you correctly, when you adjust the clearances by the book, The motor will turn over easily & start, but you bend pushrods, right.

The main reason for bent pushrods is spring bind. What that means is that the cam lifts more that the spring can compress. This is because either the cam lift is too big or the springs are too compressed already.

Is is a stock or mild cam. Another thing to check is can you put a 20 thou feeler gauge in between the coils of the springs when the valves are fully open, after you have adjusted the tappets by the book. If you can't, get an engine builder to measure your valve spring set-up properly, I think that's your problem.

Dr Terry.

[SpeciFEcation]

Dr. Terry,

You may be on to something with the spring bind.

Reading back through TorqueFC's posts I am starting to assume that there is a lumpy cam in this rebuilt engine and that combined with the machined head, the different valves are why poor TorqueFC is having so many problems.

It really is hard to diagnose without seeing it.....

[earlyholdenfan]

I seem to remember some mention of a fairly wild cam for this beast! hhhmmmm.......
Matt ;)

[TorqueFC]

ahhh now that makes sense, as soon as you mentioned about the cam bells began to ring

below are the cam specs
also where there is a * it is in place of the degree sign which is not on the keyboard lol

RUNNING CLEARANCE:IN   .14"          EX.014"
LIFT@LOBE:                IN   .296"        EX.296"

ADVERTISED TIMING
Exhaust opens:        75*       closes    41*
Inlet Opens:             40*       closes    75*

.050" Valve Timing

exhaust duration:238*

SETTING SPECIFICATIONS
inlet lobe lift @ TDC on the overlap    .093"

i hope all of that makes sense

[colt]

Darcy, look at the running clearance on your cam specs. You need 14 thou clearance on both exhaust & inlet. I would say that you arent setting your gaps big enough. My cam is set at 15 thou. This may be your problem.
Colin

[TorqueFC]

hey colt

been there tried that. 14 thou still isnt enough, we ended up getting the motor running but id say that they will most likely need re adjusting. as it is now i believe that it was almost 40 thou or so. we went from the alrgest gap possible using the feeler guage, then slowly went to a smaller and smaller gap,, and 40 thou was right. the motor is not tappy whatsoever, although it is hard to tell (motor is bloody loud!!!!!!!)

anyway thanks for all of your help, hopefully we can work it out some time soon though, so we can re adjust them 100%

[Dr_Terry]

Hi Guys.

40 thou is a big gap. The motor would sound very noisy.

I don't wish to insult your intellect, but could you be using metric feeler gauges. These days that's all the tool stores sell.

40 thou = 1mm but .40mm = 16 thou. .40 is usually just marked as 40

Dr Terry.

[TorqueFC]

hi

just thought i would dig this abck up and tell ya's whats happend now. finally ot the motor in the car, and with a full exhaust the motor is really really tappy. went to adjust the tappets again, nope no way bend another couple of pushrods. anyway i measured the amount of spring that is there compared to a standard head and what do ya know, the head with 202 valves has a shorter span on the springs. im guessing this is whats causing all of the dilema and bending pushrods etc. i have thought, and re thought about it and this was the only thing i can think of. after all the mucking around and that  i thought hey what if they were different lengths, that would cause bending of pushrods and a big pain in the ass. anyway when i measured em, there is nearly 5mm differents :O:O:O

now i think maybe ill try to bolt on the other standard head that came off another running motor and see what happens, then monday morning down to the head joint to tell em to fix it!!!!!!

anyway i just thought id leave a post and maybe some one out there could clarify that this would be the problem???

[karter42]

Hi

This could very well be the problem.
I once had a customer with the same problem with a Harley Davidson. He had put a lumpy cam in and changed the valve springs and retainers. The high lift combined with the new bigger retainers was causing the underside of the top retainer to just kiss on the valve guide and bending pushrods. (he was using solid lifters) another problem was that the top retainer was hard against the rocker cover which was also causing some spring bind. A quick touch up on the linisher fixed the retainer but had to remove the valve guides and knock a little off the top of them.

Dave.

[colt]

Darcy, I reckon youve got it. From memory when I did my motor, the red motor valves are longer overall, this length has to be brought back to grey specs. The colletts are in the same spot though. Keep at it.
Colin.

[TorqueFC]

thanks colin

yeh im sure it will all work out ok. got the head off and dropepd it back, told him was nto happy!!!, he said because its such a large cam that he needs to change springs and it needs a higher seat pressure, currently it has a seat pressure of around 45, he said it will need a seat pressure around 110 (is this right??)

[nicko]

yes

[TorqueFC]

hi

got the head back today

they went through teh head, and teh cam specs, and eventually decided to fit xu1 valve springs, minimum seat pressure is 85

now tomrrow we will have the motor runnin right and il let ya's know how it goes