round teeth vs. square teeth (Efrain i need you input)

gse_turbo · Post by **gse_turbo** » Fri Nov 02, 2007 7:34 pm

while back i brought up a point with Kenny about timing system and i'd like to see what you guys have to say.

as everyone knows the timing belt is weak link, but there was never a problem like this with the 1st gen 16v motors .

the only difference that i can think of that would truly affect this is the belt style itself.

so is swapping to the older round tooth gears and belt an option? are the gears the same size (early 16v to the iron ecotec)?

garrett

gse_turbo · Post by **gse_turbo** » Fri Nov 02, 2007 10:56 pm

just compared the two cam gears and the C20XE gear has 42 teeth and the X20XEV has 46.

this just rules out using gears that are already available but i intend on making adj. gears anyways and round teeth would be easier than square to cut.

garrett

gse_turbo · Post by **gse_turbo** » Sat Nov 03, 2007 4:19 pm

Audacity Racing · Post by **Audacity Racing** » Sat Nov 03, 2007 4:41 pm

What's the diameter difference? The difference in teeth number is negligible since tension can be run on both sides of the system to adjust the slack... the primary ratio is developed by the diameter, not the tooth count

gse_turbo · Post by **gse_turbo** » Sat Nov 03, 2007 4:49 pm

Audacity Racing wrote:What's the diameter difference? The difference in teeth number is negligible since tension can be run on both sides of the system to adjust the slack... the primary ratio is developed by the diameter, not the tooth count

this is true about the drive ratio and diameter. tho i dont have a gear for a C20XE i do have the crank gear from the C20GET(same as the XE) and the T22SED. the tooth styles are different but the tooth count and diameter is the same so this leads me to believe that the diameter is smaller on the XE based on the tooth count. but like i said i dont actually have a C20XE gear to make the measurements.

garrett

Audacity Racing · Post by **Audacity Racing** » Sun Nov 04, 2007 8:52 am

If the crank pulley is the same size, so are the cam pulleys...

gse_turbo · Post by **gse_turbo** » Mon Nov 05, 2007 9:01 pm

i went back and got sild measurements... the T20/T22/U20 crank pulley is smaller and has more teeth(idon't remember the No. right now) s the C20 is bigger and has less teeth. to me this suggests that converting to the older round tooth would be stronger from that alone.

the cams and crank would have to spin at the same rate between the new and old motors so the conversion should be staight forward, you would obviously need to swap out your water pump also which is benificial.

garrett

Audacity Racing · Post by **Audacity Racing** » Mon Nov 05, 2007 9:04 pm

As seen on the Lacetti WTCC engine, I agree to the converting to round teeth

kinkyllama · Post by **kinkyllama** » Mon Nov 05, 2007 9:50 pm

gse_turbo wrote: you would obviously need to swap out your water pump also which is benificial.
garrett

Why would that be benificial? are the old ones better or something?

Hey I'm intrested in doing this conversion so if you need any help to see if it'll work outside of theory just PM me

Audacity Racing · Post by **Audacity Racing** » Tue Nov 06, 2007 6:14 am

I'm curious as to the cam position sensor input for this swap... I got to thinking and coming from a distributor engine would mean the required trip mass isn't there to trigger the sensor.

May be more trouble than it's worth, no?

Spider · Post by **Spider** » Tue Nov 06, 2007 8:23 am

Chains win!

gse_turbo · Post by **gse_turbo** » Tue Nov 06, 2007 5:33 pm

kinkyllama wrote:
gse_turbo wrote: you would obviously need to swap out your water pump also which is benificial.
garrett
Why would that be benificial? are the old ones better or something?

Hey I'm intrested in doing this conversion so if you need any help to see if it'll work outside of theory just PM me

good question... because the old water pump uses round teeth and the new uses square teeth the belt wouldn't grad the pulley properly and would prodly slip more than anything.

the other upside is that the older pump is more available and there for cheaper.

Audacity Racing wrote:I'm curious as to the cam position sensor input for this swap... I got to thinking and coming from a distributor engine would mean the required trip mass isn't there to trigger the sensor.

May be more trouble than it's worth, no?

my intent was to manufacture adj. gears anyways, if the conversion is worth wild then i'll go that route but incorperate a sensor pick-up

i just need a gear from the early model.

the round tooth is also easier to manufacture, a special tool would need to be made for cutting the square teeth.

garrett

gse_turbo · Post by **gse_turbo** » Tue Nov 13, 2007 11:17 pm

who has a early C20XE (Efrain) or like motor with round teeth? and does any one have a late C20XE with square teeth?

i need to get a measurement of the diameter for the round tooth cam gear. the count on the SOHC and the early DOHC is the same 42 and i think that means the diameters should be the same unless they used a different belt style and i don't think they did.

garrett

Post by **Efratech** » Wed Nov 14, 2007 1:47 pm

mine is a early... you making me take out the cam cover!!! its a pain in the ass to take it out!!!

mine is a 20xej

i asked at astra-mk2.com, today they should answer

gse_turbo · Post by **gse_turbo** » Wed Nov 14, 2007 5:05 pm

Efrain A. wrote:mine is a early... you making me take out the cam cover!!! its a pain in the ass to take it out!!! mine is a 20xej

i asked at astra-mk2.com, today they should answer

thanks,

XEJ!? i'm not familiar with that one, that's the J?

The original daewootech forum

round teeth vs. square teeth (Efrain i need you input)

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