Get your new damper. Press it on.

As Patcon already mentioned. Measure the thread depth to face of damper hub ( Including washer )  with the depth gauge  of Vernier Calipers. Subtract 5mm from measurement to make sure bolt doesn't bottom . Call ARP and tell them you need a Crank damper bolt Xmm x Ymm x Z mm. I'm sure that they will have something close enough. They make all sorts of single use fasteners that are not listed Online nor in their Catalogs.  

Edited July 11, 20186 yr by Chickenman

Thanks CM. I checked ARP’s site first and they list lots of damper bolts, but nothing specific in a M16x1.5. I will call them once I have the damper and see what they have. 

The washer seems to be just as important. I’m guessing they have a something that will work. 

I did verify that the Kameari bolt/washer is the right length for the BHJ damper that I am now going with. 

Jonathan, I thought about just using a rebuilt stock damper, but decided to try to make the engine more reliable this time around. 

On 7/11/2018 at 12:19 PM, Jeff G 78 said:

Thanks CM. I checked ARP’s site first and they list lots of damper bolts, but nothing specific in a M16x1.5. I will call them once I have the damper and see what they have. 

The washer seems to be just as important. I’m guessing they have a something that will work. 

I did verify that the Kameari bolt/washer is the right length for the BHJ damper that I am now going with. 

Jonathan, I thought about just using a rebuilt stock damper, but decided to try to make the engine more reliable this time around. 

Ok, I know the OP has resolved their issue but here is my 2 cents in case anyone else is asking this question / reading this thread in the future.

 

I run an ATI super racing damper on my very modified street driven L28 because it really is one of the best non-fluid dampers out there.

 

Yes the bolt does need to be longer than stock and my engine builder had one machined for me.

 

The stock pulley is 150mm but the ATI is 70mm. So it is turning the alternator and water pump at less than half the stock rated speed.

 

Cooling:

 

Have I ever overheated idling in traffic on a 30c summer's day? No. Has the temp gauge gone higher than before - totally! The gauge has gone to just over three quarters which it never did with the stock size pulley - it rarely passed half way before.

 

The temp gauge fluctuates more on and off the power than with the stock pulley.

In reality a mechanical water pump / fan will be spinning at half the speed that the stock pulley would drive them.

Charging:

 

I had my alternator rewound / uprated to 90A constant capability and a slightly smaller pulley put on. At an idle of 900rpm the volt meter dances between 12v and 13v. At 1200rpm it's steady. The LED headlights do flicker at idle between 900-1100 rpm.

Most alternators do very little below 1500 spindle rpm.

Other options:

 

Kameari do a fluid damper with two pulley sizes one closer to stock and one that iirc is about 110mm (ATI is 70mm). See RHDJapan website for the street version.

 

Another benefit is that the fluid damper will never need to be rebuilt.

 

BTW - on my stock damper on original stock engine I found it to be loose and moving 1cm back and forth!! Gulp! So it does happen even on bone stock engines.

Edited March 5, 20196 yr by AK260

Ok, I know the OP has resolved their issue but here is my 2 cents in case anyone else is asking this question / reading this thread in the future.

 

I run an ATI super racing damper on my very modified street driven L28 because it really is one of the best non-fluid dampers out there.

 

Yes the bolt does need to be longer than stock and my engine builder had one machined for me.

 

The stock pulley is 150mm but the ATI is 70mm. So it is turning the alternator and water pump at less than half the stock rated speed.

 

Cooling:

 

Have I ever overheated idling in traffic on a 30c summer's day? No. Has the temp gauge gone higher than before - totally! The gauge has gone to just over three quarters which it never did with the stock size pulley - it rarely passed half way before.

 

The temp gauge fluctuates more on and off the power than with the stock pulley.

In reality a mechanical water pump / fan will be spinning at half the speed that the stock pulley would drive them.

Charging:

 

I had my alternator rewound / uprated to 90A constant capability and a slightly smaller pulley put on. At an idle of 900rpm the volt meter dances between 12v and 13v. At 1200rpm it's steady. The LED headlights do flicker at idle between 900-1100 rpm.

Most alternators do very little below 1500 spindle rpm.

Other options:

 

Kameari do a fluid damper with two pulley sizes one closer to stock and one that iirc is about 110mm (ATI is 70mm). See RHDJapan website for the street version.

 

Another benefit is that the fluid damper will never need to be rebuilt.

 

BTW - on my stock damper on original stock engine I found it to be loose and moving 1cm back and forth!! Gulp! So it does happen even on bone stock engines.

IIRC, your engine builder used the Kameari crank damper bolt and washer Ali.

I also ended up with the Kameari bolt and washer.

IIRC, your engine builder used the Kameari crank damper bolt and washer Ali.

Nope Jon, he used the washer but the bolt was too short for his liking on the ATI so he had one made just like it but longer ...

 

 

Kameari on right new on left with washer on. You can just about make out that the new bolt is about a bolt head longer.

Oh and I forgot to mention, if you are attached to the classic look of a mechanical fan like I am, then you have to space it forward by about 7mm to clear the stickie outie bolts on the front of the damper.

 

Nope Jon, he used the washer but the bolt was too short for his liking on the ATI so he had one made just like it but longer ...
 

 
Kameari on right new on left with washer on. You can just about make out that the new bolt is about a bolt head longer.

I stand corrected. It works fine on the Kameari damper :)

Oh and I forgot to mention, if you are attached to the classic look of a mechanical fan like I am, then hounded to space it forward by about 7mm to clear the stickie outie bolts on the front of the damper.

That's true with the Kameari damper too. I clearanced the back of the fan blades by about 1mm to miss the damper. I couldn't space the fan forward because my fat radiator is in the way.

I got around to installing the BHJ damper today.  It went on great using the crank bolt to draw it in.  The 0.001" interference fit made it tighter than a stock damper, but it pulled in very easily with the bolt.  The Kameari bolt and washer were just the right length.  The only thing I need to do now is fabricate a new pointer as the scale on the damper it forward of the pulley rather than behind it like the stock damper.  Since the whole reason for the engine teardown and new damper was a loose crank bolt, I used red Loctitie this time around.  ?

That is one sexy bit of kit!!!!! Nice work.

 

This is what I had to do - it's rather large but it will never vibrate onto the damper especially as it's 2mm thick steel ;)

 

 

 

 

I had an ATI dampener on last year's race engine and we had no issues. This year's  engine is a rebuild using parts from an earlier race engine. That engine had a BJH dampener which if not kept oiled begins to rust pretty quickly.  Inspection of the crank months ago revealed no damage or scoring. Today I got a call telling me that the inside of the dampener was damaged. I will post a picture tomorrow once I get a chance to go see it. An ATI is on the way. We did not install the BJH so I'm unsure why.