matt87FC

iTrader: (12)

ok so this may seem dumb but I have to ask anyways since searching hasn't turned up anything for me for some reason. So basically I am getting ready to be able to start up my swap, and I am now doubting myself and thinking I MAY have used my n/a hub pulley on the t2 hub.

I know the holes are offset on the hubs so that the pulley can only go on one way, so is it even possible to put an n/a pulley on t2 hub? IF so, is the leading timing mark different between t2 and n/a? The pulleys both came off an s4, just one was n/a and one was t2. I cannot find my other pulley now to compare them so thats why I am here asking you guys.

So any help would be appreciated. I dont want to just wing it on the timing since I am building a high compression 4 port t2, so a few degrees off could be even worse for me than normal as far as detonation issues.

SpikeDerailed

iTrader: (7)

The hubs and pulleys are matched pairs. While they can be interchanged they should never be. If you're in doubt find a known matched pair and verify you have the right combination on your car.

The timing marks arent a tii or n/a thing, its a matter of if the pulley is proper for the hub, its its not the timing marks WILL be off.

RRTEC

iTrader: (13)

Ok,

Pulleys are year specific (i accidentally used an s4 pulley on an s5 motor once..) T2 to N/a Doesnt matter as much as series of the car. The timing marks are different between series.

Buy a used Racing Beat main pulley, line your current one up after you set it with the RB one and then mark the old pulley to match.

Done.

RotaryEvolution

iTrader: (30)

i suppose i should just start doing this as a service as well since i have the fixture all made in order to set the pulleys up to perfect timing at TDC, 5ATDC and 20ATDC.

anyways, if anyone needs a timing pulley to be matched for the markings you can contact me and i'll do the service for $25 plus return shipping.

if you think you may have borked it you can swap the pulleys on an engine and see if there is any difference in the timing marks, some are a bit off but sometimes you get lucky and have 2 that are relatively similar and swappable without any adverse affects.

matt87FC

iTrader: (12)

The pulleys and hubs are both s4 AND from the same year in fact. So does anyone know how different they are or is it really made specific for each engine? I find it hard to believe that mazda made custom hubs/pulleys for EACH AND EVERY engine produced for these cars and can never be mixed and matched. Does anyone have any concrete evidence from mazda on this subject?

KARACK- I may take you up on that offer. Ill pm you if i chose to do so.

j9fd3s

iTrader: (3)

i tried a stack of pulleys and hubs, and most of them were close, but there were a couple that were way off. so it seems like they are a little sloppy, and then there is the odd one that's just way off.

i would do what Karack suggests, and put the other pulley set on, if it matches, you're fine if it doesn't then you get to try and figure out which one is right

RotaryEvolution

iTrader: (30)

yep, i've tested a few as well and there is no real rhyme or reason why they aren't all machined the same way.

seems to me they never planned on the pulleys to ever be removed from the engine and were all machined by hand and have some give in any direction by a few degrees until you get into different engine series and then there is a much wider margin if you mix them up.

bumpstart

only in the US,,where your s4 turbo and NA engine share the same spark locations which is different to s5


in the rest of the world , s4 NA IS the odd man out in relation to spark positions
these DO have a unique hub that is around 20 degrees offset if placed onto any other engine ( besides the US n332 s4 turbo )
unfortunately the hub itself will take any of the s4/5 pulleys ,, which brings us to these issues

i have posted multiple pics in other threads with all the hubs lined up by keyway and the effects this has when you swap pullies in relation to the timing mark pin

the best way to find TDC or 5 ATDC is to used a matched hub and pulley and place it on an engine that has the keyway at 9 oclock ( 270 deg )

if you are not confifent to pull off the hub without messing up the endfloat
then you can line the engine to put the front keyway at 270 by observing the position of the flywheel balance bite,, or from the wings on the auto counter balance
EG

if you have a standard flywheel on,, ( view from rear ) then the bite missing from the back ring will be pointing at the exhaust at 3 oclock
if you have an auto counterweight ,, then the bumps will at 9 oclock ( view from rear ) down the spark side
( look down inspection cover )

RotaryEvolution

iTrader: (30)

that's still only a rough way to check timing and can be up to 15 degrees off even if it looks correct. problem is you line up the pointer and if the wing is somewhere between the 2 tension bolts you begin to wonder if you're looking at it from the right angle and accept that it's "close enough".