750rwhp carnage

[quake]

first i stretched a stock t-belt, next i ripped 5 teeth off a new t- belt so i replaced it with a gates. Now this... this is all that is left of my oil pump drive shaft pulley. I think with the low belt deflection it may put too much stress on the shaft

 

[IJ.]

Seen a few of these that have exploded like that, quite often the slightest nick/mark on a spoke during assembly is enough to set it off as the pully is "sintered".

Pulling teeth off the timing belt is a concern what valve springs?

Are you preloading the timing belt on install, also what torque on the tensioner?

 

[quake]

ok i thought i was the only one. Quite possible with a nick as it was original. Valve springs are com cam bbc springs so not crazy tension. Preload was slightly past spring tension, and stock tq on the tensioner.

 

[IJ.]

A lot of times when poeople torque the Pully bolt they use a tool in by a spoke to the timing case and causes a "cut along dotted line" stress riser
(seen a bunch of these over the years so you're NOT the lone ranger this time Q)

I replace the tensioner spring each build and don't preload, can't see the Comp springs shearing teeth so something else is going on there (what's the seat pressure at installed height?)

Dumb question but is the lower pully facing the right way?

 

[quake]

i have a strap wrench that i use it is like leather, it goes around the gear like a chain wrench so no damage. All sprokets were assembled properly, but the crank bolt was not that tight anymore was at the factory spec when installed and had thread lock on it. Was thinking maybe harmonics as it is a stock crank pully?

 

[IJ.]

Was thinking more of before you got it damage..

Measure the snout on the crank and make sure it's not tapered (might have had a wobbly crank at some time in it's past)

Stock Damper is pretty useless at that HP level, even the off the shelf ATI isn't going to cut it for long you'd need one like Duane's special order unit.

 

[aznboik1mva]

first i stretched a stock t-belt, next i ripped 5 teeth off a new t- belt so i replaced it with a gates. Now this... this is all that is left of my oil pump drive shaft pulley. I think with the low belt deflection it may put too much stress on the shaft

this is how i got my first supra..the guy said he heard clunk clunk, lost oil pressure and the car wouldt start. 200$ and then 150 in parts and had a runnin 1991 targa 5 speed turbo mk3

 

[NashMan]

now i kinda wana cheak mine

never even thought of this or scean it that much

 

[quake]

i may pull it and use my spare crank, also i was lazy about the ati but after speaking with them about a custom pulley i was not impressed. I may also have a custom sproket made.

 

[quake]

so here is the plan.. on monday i wll pull the motor pull the crank and have my spare machined and balanced while i wait. Then go back to work and reassemble if all goes well it should be ready to start the same day.:icon_bigg

 

[hvyman]

Sweet!

 

[IwantMKIII]

is this still the stock (internals) motor from a long time ago?

 

[upgradedsupra]

i may pull it and use my spare crank, also i was lazy about the ati but after speaking with them about a custom pulley i was not impressed. I may also have a custom sproket made.

Since I had my custom ATI pulley made, they still have the drawings therefore should cost you less than what I paid. You have to pay to play Q!

Duane

 

[toyotanos]

You may consider trying a 5M oil pump drive pulley. They are not the "5-spoke" style that the 7M's use, they have 6 holes drilled into them so there is more material for it to hold together.

Pic: center picture on page.
http://yotarepair.com/ToyImages/5m-ge6.gif

 

[SupraJerry]

You may consider trying a 5M oil pump drive pulley. They are not the "5-spoke" style that the 7M's use, they have 6 holes drilled into them so there is more material for it to hold together.

Won't work, different belt tooth profile......

I've seen a custom aluminum oil-pump pulley here somewhere.

Are you running the 6M crank by chance ?

 

[Enraged]

if you measure the stock pulley, you could make a new one pretty easily. you can buy stock from https://sdp-si.com/eStore/ and then have the depth and bore cut at a machine shop.

 

[quake]

Since I had my custom ATI pulley made, they still have the drawings therefore should cost you less than what I paid. You have to pay to play Q!

Duane

i don't care what it cost but the guy i spoke with back when did not seem very informed when i spoke with them about a custom pulley.

---------- Post added at 05:27 PM ---------- Previous post was at 05:24 PM ----------

thanks for the help guys. A vendor should pick up on this and make one Hint Hint

 

[NashMan]

Won't work, different belt tooth profile......

I've seen a custom aluminum oil-pump pulley here somewhere.

Are you running the 6M crank by chance ?

that is incorrect and half ture the 84 85 are the same that's when they changed the belt to the same profile as 6m and 7m

i found that out with mk2 motor swap i used a 83 motor in 85 car and only had an 85 t belt so i had to swap the pulleys over and stuff


so if ti has knock sensor that is the one with the proper pulley


i might just swap to this now if i can find one

 

[Moy]

Since I had my custom ATI pulley made, they still have the drawings therefore should cost you less than what I paid. You have to pay to play Q!

Duane

If you don't mind me asking, how much did it cost you, and how many belts do you run?

 

[IJ.]

There are many high HP 7M's running with heavy valve springs that aren't killing the AUX pulley, I still say at some time in its past someone has marked nicked a spoke during install and being a sintered part it's a fail point, buy a new stock pulley deburr it carefully and install it exactly as Q described earlier in this thread and it will be fine..