bore out a 4g32 saturn by 0.75mm safe?

[shuggy]

make sure the 4g32 head has the same amount of teeth on the cam gear as the 37, otherwise it wont work, easiest way would be change the gears over..

[topps]

yeah i transfered almost everything into the g32 head. rockers, camgear, camshaft.
that is why i dont see any issues that needs to occur.
im guessing i may be doing the installation of the belt incorrectly but im puzzled why is it hapening always on the 8th revolution of the crankshaft pulley.
and it always stops a the BTDC mark. *weird*

[shuggy]

doesnt make sense to me, if the camgear is the one matched to that block tehen there shouldnt be an issue..

[DanTurboLancer]

Might check?
- Number of teeth on 4G37 Cam Gear
- Number of teeth on 4G32 Cam Gear

- Number of teeth on 4G37 Crank drive gear
- Number of Teeth on 4G32 Crank drive gear

May have a miss matched gearing causing cam to lose its valve timing??

Has 4G32 head been machined and checked?

-------------------------------------------------



Hey Driftforlife

The bigger your pistons, the more weight the crank has to move.
Tends to make them less rev friendly.
If you can get away with not Boring and replacing Pistons, or fitting oversize pistons,
and can get away with just a Hone.

Spend your money on getting a good machine shop to check it all out and getting a good quality bottom end rebuild.
and then you might invest in more in head work.
Good carbs, exhaust and a Tune.

As an apprentice i hope you are going to give this ago yourself mate
Plenty of guys onhere to give you tech support.

And not to put a negative spin on it, (Touch wood now) if it was to have a catastophic failure,
because it hasnt been bored to max, you can get it bored out and reuse that block instead of chasing another one.

Just thoughts mate, Its your motor.
Have fun with it!
See you at the next cruise

[DanTurboLancer]

Hey Topps i just found this,
May help??


http://japanesenostalgiccar.com/forum/v ... php?t=5444


Cheers Dan

[topps]

thanks dan!

i think i transfered all the 4g37 parts on the 4g32 head. (except for valves)
so if im using the same 4g37 crank drive gear and cam gear, there shouldnt be any issue.

i guess there really is a mismatch in the gearing. have to be more careful with this one.

i guess city hunter had a better grasp of the topic. oh well, wish me luck mates.
thanks again.

[toruhiwi]

I have an early 4G32 balance shaft (square tooth belt) I fitted with with 4G37 (round tooth belt) camshaft and cam, crank, oil pump gears. I did this a few years ago and don't recall counting the teeth, but I don't think this is your problem.
The 4G73 was an early Nimbus with adjustable tappets.

Try backing off the tappet clearance, you may have a valve on fouling one of those high crowned pistons, especially if the head has been machined a number of times......

Roger

[77GDWAGON]

[quoteTry backing off the tappet clearance, you may have a valve on fouling one of those high crowned pistons, especially if the head has been machined a number of times......][/quote]

I thik this is your problem. 4G37 pistons wont work in a 4G32 unless they are machined. 4G37 head has larger chambers to acomodate the dome pistons. 4G37 has 9.5/1 CR
4G32 with 4G37 pistons = 11/1 CR or higher