Re-install IP on a 12HT (1 Viewer)

[watrob]

The problem is the rebuilt engine as the harmonic balancer already on, there is a exposed gear you can see where the IP bolts into has a set of 2 teeth with blue paint on them, there is a set of 3 times with blue paint thou.


I would assume that you would set the harmonic balancer at 11 deg BTDC?, see the attached photo shows.


The problem is which one of the 3 sets of blue lines marked on the gear to use, you can in the attached photo the twin blue lines which are exposed at 11 deg (and down lower another set just exposed).


The third photo shows a plug on top of the casing where the IP bolts onto, this is a inspection point to check the gear position.


The last photo is of the IP gear, I have checked everywhere on this gear and the only thing I can find is "2", does one highlight this tooth so it shows thru the inspection plug or does this tooth go between the teeth of the gear with the 2 blue lines?


How does one re-install a IP without pulling the harmonic balance off and the front gear cover off?

PS. Is it 4 revolution of the crankshaft for firing? so as each set of blue line pass by, the last set of blue lines at BTDC 11deg that are exposed is where the IP is "positioned, by painting the tooth that has the "2" on it, that is what needs to be seen thru the inspection plug?..............anyone for comment?

 

[lostmarbles]

I think you may need the timing cover off so as to be able to align both "2" timing marks Robert.

In other words, I think you need to align the "2" mark you've shown on your automatic timer (that fits on the IP drive) with the hidden one (facing the inside of timing cover) on the No.1 idle gear (that has those mysterious blue marks on it's teeth).

Then all's good when you have:

• the two "0" marks aligned between the crank timing gear and No.1 idler
• the two "1" marks aligned between No.1 idler and No.2 idler
• the "3" mark on the camshaft gear between the two "3" marks on the No.2 idler, and of course
• the "2" mark on No.1 idler with the "2" mark on your IP cog as mentioned above

But I know you're after another way that doesn't involve removing your harmonic balancer and timing cover ...

I'm interested to see if there is one too.......

 

[watrob]

I think you may need the timing cover off so as to be able to align both "2" timing marks Robert.

In other words, I think you need to align the "2" mark you've shown on your automatic timer (that fits on the IP drive) with the hidden one (facing the inside of timing cover) on the No.1 idle gear (that has those mysterious blue marks on it's teeth).

Then all's good when you have:

• the two "0" marks aligned between the crank timing gear and No.1 idler
• the two "1" marks aligned between No.1 idler and No.2 idler
• the "3" mark on the camshaft gear between the two "3" marks on the No.2 idler, and of course
• the "2" mark on No.1 idler with the "2" mark on your IP cog as mentioned above

But I know you're after another way that doesn't involve removing your harmonic balancer and timing cover ...

I'm interested to see if there is one too.......

There has to be another way, I cannot see that a IP service shop would remove the grill, radiator & water, take off a harmonic balancer and then the gear cover just to service a IP?

 

[watrob]

Via the harmonic balancer set to the (rotating clockwise) last grove which is TDC, the groves as they pass by are 18deg BTDC (2H), 11deg BTDC (12ht) and the last grove is TDC.


There are only 2 rotations, TDC will be either on piston 1 or piston 6, you want piston one ( both inlet & exhaust valve rockers need to be loose on piston 1)


On the IP (see photo below) you will find a flat spot on one of the teeth on the IP gear on the IP housing side , paint it white as this tooth needs to visible and centred in the middle of the inspection hole on the side of the front case by removing the small plug.


All done!

 

[lostmarbles]

OK, thanks to Diesel Australia the easy way to re-install your IP:-


Via the harmonic balancer set to the (rotating clockwise) last grove which is TDC, the groves as they pass by are 18deg BTDC (2H), 11deg BTDC (12ht) and the last grove is TDC.


There are only 2 rotations, TDC will be either on piston 1 or piston 6, you want piston one ( both inlet & exhaust valve rockers need to be loose on piston 1)


On the IP (see photo below) you will find a flat spot on one of the teeth on the IP gear on the IP housing side , paint it white as this tooth needs to visible and centred in the middle of the inspection hole on the side of the front case by removing the small plug.


All done!

Great discovery Rob

I suspect this may be something the Diesel Injection Shops like to be kept secret.

BTW- In your other thread (the build thread) you've mistakenly typed "loose on piston 6".

 

[yotahed]

Nice. I figured there must be an easier way if the 3B and 13BT were so easy...

 

[watrob]

Ok, IP installed, harmonic balancer set to TDC on piston 1 and the tooth on the IP gear with the shaved edge is smack dead in the centre of the inspection hole!

 

[Fern1109]

Hi guys,

I'm having the same problem, I'm installing a 12ht on my 1984 hj45 and every time I cranked the engine it goes from O rpm to wide open so I took the IP out and rebuilt it. The injections rack was stock and wont let the throttle body work properly, now I'm on the same exactly place as @watrob the harmony balancer and the IP are put and I'm wondering put everything back in time.
I did what @lostmarbles says about take the timing cover off to match numbers but I've been turning my crankshaft for hours without success, at this point I feel kind of lost without knowing if turning my crankshaft I gonna get my timing properly.

This is the closest I got to make them match.

 

[Chris Wilcox]

Appologies if this is off base as I don't have direct experience with this engine. But can't you just remove the gears and re-time it?
Give me a few minutes and I'll see if I can calculate the number of turns and direction needed from your yellow marks.

 

[Chris Wilcox]

If my calculations are correct you need to turn the crank counterclockwise 118 full turns.
Alternatively you could turn it another 3,656 turns clockwise to get it back in time.
Or just pull the gears and reset everything.

I double checked the calcs and I believe this is correct provided the gears are 32T, 51T, 37T, 64T. If I counted wrong tell me the right numbers and I'll plug it into excel.

 

[roma042987]

Hi guys,

I'm having the same problem, I'm installing a 12ht on my 1984 hj45 and every time I cranked the engine it goes from O rpm to wide open so I took the IP out and rebuilt it. The injections rack was stock and wont let the throttle body work properly, now I'm on the same exactly place as @watrob the harmony balancer and the IP are put and I'm wondering put everything back in time.
I did what @lostmarbles says about take the timing cover off to match numbers but I've been turning my crankshaft for hours without success, at this point I feel kind of lost without knowing if turning my crankshaft I gonna get my timing properly.

This is the closest I got to make them match.

View attachment 2368624

View attachment 2368627

No need to do all of that. You don't "need" the idler gears to be in time. They are simply idler gears. Only the cam shaft, pump and crank need to be in time. If the engine you're working on is still disassembled like in the photo above. I would just remove the two idlers, and reinstall them matching the crank and cam marks. Again, they, "idlers" don't "need" to be in time but what I described is easiest path forward. Lastly, easiest to Install the pump while you have the front cover off so you can line that one up with the markings on the gear face instead of the inspection hole.

 

[Fern1109]

If my calculations are correct you need to turn the crank counterclockwise 118 full turns.
Alternatively you could turn it another 3,656 turns clockwise to get it back in time.
Or just pull the gears and reset everything.

I double checked the calcs and I believe this is correct provided the gears are 32T, 51T, 37T, 64T. If I counted wrong tell me the right numbers and I'll plug it into excel.

Thank you for do the math haha that open my eyes to know i don't wanna turn this engine!!!!

 

[Fern1109]

No need to do all of that. You don't "need" the idler gears to be in time. They are simply idler gears. Only the cam shaft, pump and crank need to be in time. If the engine you're working on is still disassembled like in the photo above. I would just remove the two idlers, and reinstall them matching the crank and cam marks. Again, they, "idlers" don't "need" to be in time but what I described is easiest path forward. Lastly, easiest to Install the pump while you have the front cover off so you can line that one up with the markings on the gear face instead of the inspection hole.

That sound pretty logic to me and easier to do. the engine still the same as the pictures I posted so I gonna do this to install the pump and finish this faster.

Thank you for the advise @roma042987