Belt problems? with V7-JT supercharged engine

[azgolfrat]

Hey Guys,

Got about 100 miles on the new engine after start up & tune with Marty (some heavy duty draws!) and started to hear an occasional squeal when driving car when its cold. Then I began to hear an odd frequency noise from the front of the car, a low frequency vibration sound that repeats about once per second. I also noticed a very light coating of black dust on the front side of the timing chain covers. Then, when cold and idling, turning on the AC creates an ungodly set of noises. If the A/C is turned on when the engine is at temp from driving, the noises do not occur.
The belt, which is not OEM length, as the supercharger install requires a different length belt, looks ok, no obvious damage seen. However it does seem to deflect quite a bit when pressed down on with pressure from my index finger. Maybe 3/4 to 1 inch.

One last turd, the tensioner is new, but its a Delco part. It had to be slightly modified to fit with the supercharger install; the small "fin" on the back end was taken off with an angle grinder. This is per supercharger install instructions from Chris at ADTR (ha ha...the Delco thing wasn't Chris's instruction).

Again, this problem wasn't present until after about 100 miles.

Thoughts?

[blazen71]

6 or 8 rib belt? What size S/C pulley? You are getting belt slip which is common with a 6-rib belt and a smaller S/C pulley. An 8-rib belt is the common solution. There are a few cheaper/easier things you can try first.

1. Gates RPM belt https://www.gates.com/content/dam/ga...t-newbrand.pdf

2. Stiffer belt tensioner. I assume you're using the stock Marauder timing cover. https://americanracingsolutions.com/...elt-tensioner/

3. Griptec S/C Pulley https://zpegriptec.com/

[justbob]

Make sure the blower pulley is 100% true with the rest. Quite often the blower bracket needs a few slim washers behind it to track true.

Jerry makes a stand off bushing for adding another idler pulley on the long run from the alternator down to the power steering to address belt slap. It works great!

As for a tensioner, I wouldn’t bother with anything less than $400 and brand name myself. It is literally the key to achieving proper boost. The car I sold was a manual tensioner and I loved it. When it was a Trilogy car I ran a ThumpRRR tensioner at 20#s boost and never once had slip.


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[Blown3.8]

8 rib setup on the one I did. Stock tensioner. Just shimmed the blower as best I could like Bob said. 26psi it makes some dust but no belt noises.

[azgolfrat]

Hi Guys, thanks for the info.
The belt is a Gates Micro-V K06116 , also has 6pk2827 printed on it. 6 ribs. JEG's lists it as 111.29 length and 111.86 outside circumference. Interestingly, I cant find it on the Gates website. The link from Blazen (thanks) points me to a little bit shorter possible replacement.

The SC pulley is hard to get to in order to measure, and the SC kit supplier isn't sure what size it is (2.5 yrs ago shipped), but I made up a sorta gauge and got close..
from outside surface of belt on pulley to outside surface of belt on pulley, 180 degrees apart - 3.44 inches. If you subtract off twice the belt width you get 3.12 inches. So, not sure if it is a 3.2, 3.33, or 3.4 OD.

Couple things
1) At this point the engine makes the noises I described above well before boost ...in fact at idle
2) At idle , if I stand on the side of the engine and fix my line of site on the plane the belt is turning in, I can see a low frequency movement back and forth (left to right, right to left)) of the belt; not much, but perceptible.

Questions -
1) if one goes to 8 rib, all the 6 rib pulleys are being changed out, correct?
2) can you give me a primer on how to check for belt alignment of SC pulley with everything else and how to go about shimming if needed (I'm guessing shim(s) between the pulley and the SC?).
3)A manual tensioner is not the spring-loaded type? Get the belt where you want then tighten?

Thank very much guys. Still learning a metric butt load.
-KK

[justbob]

Shims go between the blower bracket and the block. As for alignment I’ve always just done it by eye but Gates sells an alignment laser that I’ve seen work awesome.




My manual tensioner was for a 2” wide cog drive pulley kit on my centri build. I ran manual tensioners for both accessory and blower.


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[blazen71]

I have a gates Drivealign and they work pretty good. The trouble is there's a lot in the way of the laser so it can be difficult to get to the S/C pulley. It does sound like at the least you have a belt misalignment if you can see it move. Check the sides of the belt for wear. That's a sure sign. For reference I have a 6-rib belt and 3.4" S/C pulley and that is right on the cusp of slipping even with all the preventative measures taken. If you switch to an 8 rib you will have to change every pulley including a new harmonic balancer. I can help you with the pulley p/n's if you ever decide to go that route. I will be changing to an 8 rib this year when I put a smaller S/C pulley on. The extra idler pulley Bob mentioned is a great addition if it fits. Another member here, local to me, put the same Vortech S/C on his Marauder with a stock marauder timing cover and the Vortech bracket below the alternator was in the way of putting the extra idler on? I have a Procharger so the brackets are different from a Vortech but here's a pic anyway. You can see in the pic that the edge of the belt is worn and the cords are showing. Look for that on yours. Have you changed all the pulley/pulley bearings? Maybe you just have a bad bearing in one of the pulleys? I would also mark the min and max of the tensioner range of movement and make sure it is at least half way or tighter.
Attachment 52348

[azgolfrat]

I have a gates Drivealign and they work pretty good. The trouble is there's a lot in the way of the laser so it can be difficult to get to the S/C pulley. It does sound like at the least you have a belt misalignment if you can see it move. Check the sides of the belt for wear. That's a sure sign. For reference I have a 6-rib belt and 3.4" S/C pulley and that is right on the cusp of slipping even with all the preventative measures taken. If you switch to an 8 rib you will have to change every pulley including a new harmonic balancer. I can help you with the pulley p/n's if you ever decide to go that route. I will be changing to an 8 rib this year when I put a smaller S/C pulley on. The extra idler pulley Bob mentioned is a great addition if it fits. Another member here, local to me, put the same Vortech S/C on his Marauder with a stock marauder timing cover and the Vortech bracket below the alternator was in the way of putting the extra idler on? I have a Procharger so the brackets are different from a Vortech but here's a pic anyway. You can see in the pic that the edge of the belt is worn and the cords are showing. Look for that on yours. Have you changed all the pulley/pulley bearings? Maybe you just have a bad bearing in one of the pulleys? I would also mark the min and max of the tensioner range of movement and make sure it is at least half way or tighter.
Attachment 52348

JB and Blazen, as always, Thank you :-)
Blazen, the only new bearing was with the SC pulley. I gather from posts I read that pulley bearings go out a lot on this engine. I wish I had known more when I had that baby on the engine stand. oh well.
I will mark min and max on the tensioner and check for "half way" as you suggest.
I think I could add an extra pulley between the alternator and the PS..see photo/arrow... is this the proper location? If yes, could you point me toward the correct 6 rib pulley?
new pulley locn.jpg

[blazen71]

You will have to look around for a pully for the location you're pointing to and see what fits. The pully would need a big offset. That boss is pretty far away from the belt. I have mine mounted to the left of that with a spacer, using a timing cover bolt hole. I'm pretty sure the location I'm using wont work with your set up.

[blazen71]

I pm'd you the the 8-rib part numbers. Or you can buy this kit and take out any guesswork https://www.lethalperformance.com/bg...rocharger.html

[Blown3.8]

Get the the tensioner as tight as you can and still get the belt on. A manual tensioner on the driver side would be perfect.

On Sherms whipple I remove the blower pulley to get the belt on. Cause I cant get the belt over the pulley lip.

[blazen71]

Trilogy uses a dedicated belt and tensioner? Right?

[justbob]

Trilogy uses a dedicated belt and tensioner? Right?

Yes.


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[azgolfrat]

Guys,
After more investigation of this problem (between frequent rounds of golf) I'm pretty sure it is the AC pulley that is bad.
So, I'm going to attempt to get the pulley out & replaced without disconnecting the freon lines.
(It's pretty busy under there with the sway bar, the SC air pipes and the transmission cooling lines providing interference)

But in any case, I have to get the belt off...seems trivial, but with the Supercharger in the way and the particular tensioner I have on there (non OEM), I'm having difficulties.
Can anyone suggest a BKM (best known method) for rotating the tensioner?

I've tried to grab is with big channel locks, but the angle required to get in there makes it difficult to grab.
I modified an ADTR tensioner wrench, but it is not going to work with the non-oem tensioner.

Any input would be much appreciated.
Thanks
-KK

[azgolfrat]

you guys might like this.
In order to rotate the tensioner, which couldn't be done the normal way(s), (see above)
I got a longish breaker bar, put it straight up and down on a floor jack and raised it from underneath the car into a little nook on the tensioner on the pulley side.
Wala.
-KK