Supra Dr

iTrader: (14)

As the na-t is becoming more popular, i have a basic question regarding cam timing.
I'm trying to help some one out , i searched here & SF looking, found little info.
In order to lower the CR a thicker head gasket is used. In general 1 - 1.5mm thicker than the
original gasket. Therefore the distance between the crankshaft & cams has grown that distance.
Do you need to use adjustable cam gears to degree the cams back in or is the differance
in new deck height so small that it doesnt matter?

The way i see it in theory the change in deck height would change the cam timing & the
total effective engine timing. It shouldnt effect normal drivability, but you could be missing out on some wanted HP.

Any experianced advice would be helpful
thanks
john

liberty

my friend who knows some things about this says....

liberty

to have this effect timing you would have to deck the head and block enough where you are changing 1 to 2 pts on compression....

ive heard very few cases of this problem, also make sure the belt tension is still good...

but if this was a problem then adjustable cam gear would fix regardless some good power gains can be made with cam gears i know stock tt supras make some where over 10rwhp with cam gears alone

Supra Dr

iTrader: (14)

right its basically the same problem as if you over milled a head or block, but in reverse.
the engine is growning in height. sounds as tho it really isnt a problem for most. the reason
i put this up is i have 2 seperate people w/ done, but problematic, NA-t's. i haven't seen
either car in person, but from their explainations & 'the tuners', its a timing issue. the intake
cam side of the belt sounds like its a 1/2 tooth off from cam to crank (about 5 degrees on the crank).
so i wasnt sure when you did the thicker headgasket you had to run adjustable cam gears or
do something else when doing the build up.
i'll leave it as installation error for now. unless someone else chimes in w/ another view.
thanks again
john

Jmcboost

iTrader: (10)

I've asked around about this too. Mark from ClubNA-t says that the affects are so small that you wouldn't know the difference. I Be that the timing is off enough to make a little difference but not much.