IW HB with Rollmaster dual chain?
09-27-2014, 06:43 PM
#1
Team Owner
Thread Starter
IW HB with Rollmaster dual chain?
I sent my flip drive for the cog belt conversion to ECS a few weeks ago and received it back this week. Alex had to replace my Summit HB with an Innovators West overdrive HB in order to properly make the conversion. I neglected to ask him if the hub needed to be machined like my ASP pulley was so I emailed him asking but thought I'd post here in case someone has already done this combo and knows the answer.
When I originally did my heads/cam job back in '02, I installed an ASP underdrive crank pulley along with a Rollmaster dual-width timing chain. The addition of the dual-width chain required the use of the included oil pump spacers which moved the oil pump slightly forward relative to the crank snout and closer to the crank pulley. Because of the forward displacement of the oil pump relative to the crank pulley, I machined the hub portion of the ASP pulley to clear the oil pump properly. At the time, this was considered a necessary mod to fit the dual chain setup. I never confirmed if there would have been interference between the oil pump and ASP pulley - I took people at their word because that's what was being broadcast on the LS forums at the time.
I was wondering if I need to machine the Innovators West harmonic balancer hub in the same way I did the ASP pulley hub to ensure I clear the oil pump. Can anyone tell me if this is necessary?
Here are pictures illustrating what I did back then:
I had a shop increase the length of the “A” dimension by ~.150”
You can see how the thicker dual chain/sprocket setup would force the oil pump to sit further forward relative to the crank snout and HB hub in order to clear the dual chain and sprocket thickness.
The spacers sit behind the mounting bolts between the oil pump and block. These are the spacers.
Stock chain/sprocket
Rollmaster setup
When I originally did my heads/cam job back in '02, I installed an ASP underdrive crank pulley along with a Rollmaster dual-width timing chain. The addition of the dual-width chain required the use of the included oil pump spacers which moved the oil pump slightly forward relative to the crank snout and closer to the crank pulley. Because of the forward displacement of the oil pump relative to the crank pulley, I machined the hub portion of the ASP pulley to clear the oil pump properly. At the time, this was considered a necessary mod to fit the dual chain setup. I never confirmed if there would have been interference between the oil pump and ASP pulley - I took people at their word because that's what was being broadcast on the LS forums at the time.
I was wondering if I need to machine the Innovators West harmonic balancer hub in the same way I did the ASP pulley hub to ensure I clear the oil pump. Can anyone tell me if this is necessary?
Here are pictures illustrating what I did back then:
I had a shop increase the length of the “A” dimension by ~.150”
You can see how the thicker dual chain/sprocket setup would force the oil pump to sit further forward relative to the crank snout and HB hub in order to clear the dual chain and sprocket thickness.
The spacers sit behind the mounting bolts between the oil pump and block. These are the spacers.
Stock chain/sprocket
Rollmaster setup
Last edited by Patches; 09-27-2014 at 06:51 PM.
09-27-2014, 11:37 PM
#2
Burning Brakes
I see dirt on your car!!! 
Seriously though, I have run the exact same double roller setup twice and never machined anything on the balancer. Haven't had any issues in over 60k total miles.
I do have a melling pump though and had to clearance all sorts of places to clear the chain/pump/cover. Check your chain clearance, and cover clearance with the pump spacers in there.
Also, when you go to seal it up for good. Make sure to use a very VERY thin film of silicone on the spacers to help them seal.
Seriously though, I have run the exact same double roller setup twice and never machined anything on the balancer. Haven't had any issues in over 60k total miles.
I do have a melling pump though and had to clearance all sorts of places to clear the chain/pump/cover. Check your chain clearance, and cover clearance with the pump spacers in there.
Also, when you go to seal it up for good. Make sure to use a very VERY thin film of silicone on the spacers to help them seal.
09-28-2014, 12:31 AM
#3
Team Owner
Thread Starter
The last pic is not my engine but is the same setup. I've had this dual chain and ASP HB on 12 years so it currently fits. What I need to know is do I machine the IW hub to make sure it clears. The pump is in. In fact, the timing cover is still on.
Last edited by Patches; 09-28-2014 at 02:29 AM.
10-23-2014, 03:18 PM
#5
Team Owner
Thread Starter
My machinist at work is adding in the extra clearance on the hub this week. I'm hoping to get it back from him before Saturday so I can start the installation this weekend. I will get pics up of the components in this thread when I get the HB back so you can see them before they go in.
11-08-2014, 05:45 PM
#6
Team Owner
Thread Starter
Got the HB back and, since it was kind of dull and all scratched up from all the machining at ECS and here at my machinist, I decided to polish it along with the flip drive brackets. I also cut off the part of the alt bracket A&A instructs you to and touched it up. I know none of this really shows when everything is installed but I sleep a lot better knowing it's shining under the A&A cover. 
Alex at ECS told me this is the first A&A flip drive they have converted to a cog config (they usually use Cartek's kit) so it took them a couple of extra days to go through the design to make sure they got it right. I also converted the A&A blower drive to an 8-rib when ECS told me they replaced my 6-rib HB with an IWHB that is an 8-rib pulley - figured I might as well and take advantage of running a wider blower drive belt.
Alt bracket mod
Cog modification with polished HB and flip drive brackets
I had my machinist cut in more clearance for the oil pump due to my dual chain. I had him take off another .130".
Alex at ECS told me this is the first A&A flip drive they have converted to a cog config (they usually use Cartek's kit) so it took them a couple of extra days to go through the design to make sure they got it right. I also converted the A&A blower drive to an 8-rib when ECS told me they replaced my 6-rib HB with an IWHB that is an 8-rib pulley - figured I might as well and take advantage of running a wider blower drive belt.
Alt bracket mod
Cog modification with polished HB and flip drive brackets
I had my machinist cut in more clearance for the oil pump due to my dual chain. I had him take off another .130".
Last edited by Patches; 11-08-2014 at 06:29 PM.
11-09-2014, 05:11 PM
#8
Tech Contributor
You'll need to clear off that coating where the bracket interfaces the block and the alternator chassis. Those need to be clean metal or else you're going to have serious electrical problems. The alternators chassis is what is called absolute ground. Not the frame of the car and not the battery negative post.
11-09-2014, 08:22 PM
#9
Team Owner
Thread Starter
You'll need to clear off that coating where the bracket interfaces the block and the alternator chassis. Those need to be clean metal or else you're going to have serious electrical problems. The alternators chassis is what is called absolute ground. Not the frame of the car and not the battery negative post.
I'll mark it up and clean the pc off in that area next weekend. I haven't mounted it yet so nbd at this point.
Last edited by Patches; 11-15-2014 at 04:30 PM.