Whipple 8.3 Belt Issues
 

Information Requested:
Anyone running a 8.3 litre Whipple supercharger with a cog belt?

If so have you had any issues with the belts?

I recently went to the Power Tour and did some fly bye's and the belt on my set-up was completely shaved smooth...there were pieces of rubber everywhere. FYI--- I run a Jason 1600 8mm cogged supercharger belt.

The belt looked like it was completely shaved of any teeth. It made a friggin mess in my engine compartment. I opened the hatch to see the belt loosely spinning around the pulley. It eventually slipped so much the engine died.

I then inspected the tensioners they were fine and turned the supercharger by hand to see if there was any binding and it spun freely. Adjusted the tensioners applied some tension to the bare belt to restart engine it fired up and limped back to the dock at idle. Note: I was lucky to have the tools onboard to make the adjustments otherwise it would have been a long tow back.

There are quite a few 8.3 Whipple motors out there this cannot be an isolated incident.

FYI: I run a 8mm cogged system as the previous set-up called for a ribbed belt and they had slippage problems trying to turn such large helical lobes.

Anyone have same or similar issues love to hear from you including any solutions?

KAP

P.S. I will call Mr. Whipple tomorrow but always want to hear from other boaters.

We run the 8.3 on various engines and have not had a belt failure. We run our belts so the tensioners are on the back sides of the belt.

The 44 SL I have run all summer has 70 hours and there isn't any belt dust when you open the hatch for the first time.

I would recommend going to RCD, and trying the gates powergrip GT belt and RCD GT pulleys (gear tooth profile, not the round tooth HTD).

I would not recommend a polychain, because they don't flex well, they are noisy as hell, and to quote BigYellowCat, after a days worth of boating, it will look like smurf exploded in your engine room. We have run the same 2 gates powergrip gt belts and rcd gt pulleys for 5 seasons with zero failures.

http://www.rcdengineering.com/

And what animalhouse said, put the tensioner on the back side of the belt if you haven't already.

You might also want to think about a different pulley combo (same overdrive ratio though) as to change how many teeth engage at a time and to change the forces on how your snouts/belts are loaded, because the snouts/cranks do flex.

Hello AH:

I have about a hundred hours on the belt and I inspected it frequently with no signs of wear other than a little rubber dust which is normal.

To acheive tension on the setup you need to have at least one tensioner on the tooth side.

I love my 8.3 but this latest belt failure has me quite perplexed as to the why and how it could happen!

KAP

Saxman:

Great post and informative.

I have the round tooth pulleys three of them in candy blue. It sucks to now change to another system altogether.

I like your idea and confidence in the Gates powergrip and RCD GT pulleys. I guess we must go through the evolution process but first I would like to find out why this incident occurred.

One of the tensioner pulleys on the back side of the belt was a bit wobbly but don't think that is the causation issue.

It is my lay belief that something had to stop for a second or bind up with the crank spinning to shave off all the teeth. I need to post a photo of the belt for you to get an idea of what occurred.

KAP

Here is a photo of the current set-up and belt.

http://i215.photobucket.com/albums/c...511000913a.jpg

Only one tensioner is on the tooth side. The pulley on the port side [one engaged on the smooth side of the belt was the one that was kinda wobbly but usually that side has some slack so when I spool up it has room to tighten up without too much tension.

Mr. Whipple has been away so I will discuss further with him what to do. I should also post a photo of the belt it looks like a ribbed version now smooth all shaved down no teeth whatsoever.

KAP

Keep us posted if you don't mind?

I'm building new power, and planned to use the 8.3 over the 5, but I've heard about the belt issue as well. I thought they might have fixed the issue my now, so IF you have the time, could you let us know what Dustin says?

Thanks man, & good luck!

From what I have read, the 8.3 is the same blower as the 5, all depends on what rotor is the driving one.

Seems the 8MM rubber belt is only good for so much overdrive, then the tooth shredding starts. been thru it several times and upgraded to the kevlar or carbon belts. Only time I have broken one of them is by knocking the blower off or something running thru it

:drink: You TAFC guys are insane! :D :D

I THINK that the GT's are supposed to carry about 15% more load than the HTD's.... Don't quote me on that though.

If you switch to a GT system and get bigger pulleys (same overdrive though) so more teeth can engage, but you still tear teeth off the belt, I would say that there is some other serious issue.... The GT system and bigger pulleys should have no issues carrying the load of anything under 1500hp on a good sized screw blower.

Kinda like your Canadian WP...... :lolhit:

when you say more teeth,would that be over 50?

No real clear cut answer. A certain % more than he has... maybe go up 1 belt size and get pulley's to match it (keeping the same overdrive though).

Also, some people don't like having bigger pulleys while keeping the same overdrive ratio because it will increase your belt speed..... But, slower belt speed also means less teeth engaging per a given period of time, and obviously the teeth on Kaps belt couldn't carry the load.

no chit........

Why not change the belt at 80 hours service. Maybe it shows no visable signs but reaches it's life span. Then you would have a spare for quick emergency.

We stripped the teeth back to back on new ones too. A rubber tooth 8MM will not take the load.
depending on length of the belt something like this may be a solution
http://www.rbssuperchargers.com/Stor...83&InfoID=3921

I never had a major problem with the purple dust, no worse than the rubber belts

I dont think the kevlar belts can be tensioned from the back side. It supposedly breaks down the strength. This is just what I have been told, it is very possible I'm wrong.

Comment:

I like your recommendation concerning the belt. The standard Jason belt is still $145... pay a little more for piece of mind the belt you recommend is only $179.00.

The overdrive should not be an issue.

It makes me wonder why the manufacturer wouldn't simply recommend or require this type of belt referenced above. Nah! I think something else is the problem no jumping the gun just yet. Mr. Whipple will know what the solution is to this issue.

BLEE, I will follow up for you on the outcome.

KAP

P.S. I called and left a message at Whipple will try once more again tomorrow.

Actually better than that, the Jason Gold belt. But this can't run with "GT" style pulleys.

There are no belt issues with 8mm. How many hours do you have on the belt? Had you inspected it recently to see cracking? Are you running the belts loose or tight or somewhere in between? Are you sure the motor isn't detonating, floating valves, hitting rev limit....? If so, you'll rip the teeth off. I had that at desert storm 2 years ago, floating the valves on 1 motor and it would rip the teeth off as the motor was missing up a storm @ 6000+.

The 1600 standard Jason is just a stanard run of the mill belt that works in 99% of applications. The Gates is the next best belt which has more kevlar inner support. Then the Jason Gold is better yet. Then you have to go to the Kevlar version but for your app, you shouldn't need any of the above.

There is not an issue with the SC or 8mm belt system. 8mm been around a long time and are just fine for these apps. The 8.3 and 5.0 are the same thing, just mirrored to other side. I had belt issues on my 48' OL for the powerboat shootout, but my push rolds were far too long (oops) and it was floating the valves. Belt couldn't accel/decel with motor, sc's like a flywheel, wants to keep going. So rev limits, loose belts, detonation all can hurt the belts.

Comment:

I have 94 hours on the belt inspect all aspects of the motor when launching kinda like a plane. Turn motor over primary concern is making sure water is flowing into strainer.

Then observe belt tension on everything to see if any chatter or slop. Then close hatch and run it. The belt tension is about .30 off the tensioner on the port side. Not to loose and not too tight is what I was told by you. Observe it with just enough freedom to tighten up when hammering down but not loose enough to cause it to roll over on the top.

Now tell me about detonating issues what does it do...belt wise... I thought the knock sensor jumps in at this point to take away timing to protect motor?

I have had a lot of hours on this belt perhaps I should change it every 55hours.

I need to post a photo of the belt and the light bulb will go off. The belt is intact just all the teeth are gone crazy stuff.

KAP

Be sure to set your belt tension when Motors are hot and or normal running temp. My motors grow a lot and we always had problems until we simply adjusted final tension when motors are warm.

No need to post pic of belt, thats what the rubber belts do when they fail, as there bonded to the inner liner. At 94 hours, your at the end of the belt life, if not passed it.

You can't see belt chatter unless you run all rpm's and driving conditions as many different harmonics come into play during different loads, etc.

The belts need to be pretty tight, I've tried the loose settings and semi tight, don't seem to work, they do some insane things on the dyno. When you set them up tight, they last longer and don't chatter nearly as much.

For wrap, you want to have 180deg of wrap on top, no more. The bottom, port idler is just there to lightly touch the belt, which helps with the chatter/harmonics. The main adjustment is the lower starboard idler, push this until you can't twist the belt more than half a rotation.

Detonation, the same as rev limits, and or any type of misfire causes the engine rpm to stop, or slow down abruptly, the sc, with its inertia, wants to keep rotating, then the belt gets wrapped up and twisted, then when the motor gets back to normal firing, it accelerates while the SC is decelerating, causing a massive "snap" of the belt. Its extremely violent. If you watch drag racing, they'll show slow motion camera's on the belts when the motors detonate, and its unreal how the belt coils up like a snake then snaps, back and forth until it gives. The ECM, depending on the cal, should reduce timing and richen the motor, but this is AFTER the event has occured and depending on ECM processor speed and knock control, it could in fact allow it detonate multiple firings before it catches again.

And earlier I said kevlar, but I meant carbon. The kevlar belts can't be back bent. Carbon and rubber can. Carbon is the best belt but only available in a few sizes. You'll also have to change pulleys to the "GT" tooth pattern. You don't need this, but an upgrade to the "Gold" is a good option, also produces less noise. Its available in 1400,1600,1800,2000,2200,2400 mm sizes.

I think 50 hours is a good number for changing belts, then keep the old for spares.

wow, good info. i had no idea that the belts did that.

We are prob. working the 8mm set-up as hard as anyone.
195t on the bottom and a 43t on top = 452% overdriven! That's almost 30,000 rpm at the blower @ 6500 engine rpm.
Loose is what works best for us. Every engine is different. Stripping all the teeth on a belt isn't crazy, it's just what happens when they fail. I tried running a dual idler with the one on the left side just barely touching the belt to try to "calm it down a bit". We decided the the belt hitting a stoped idler and sliding across it to spool up to speed was inducing too much heat into the belt and did away with them. Going to forced engine oiling in the snouts helped lower the snout/belt temp issues also. We have found alinement of the idlers to be critical. You can make your own spacers but Manhatten Supply has some cool stainless U shaped shims in .010 increments to really dial them in. Idler bearings that are just a LITTLE bit rough will break belts too. It's all a bunch of little things that add up. When they are wrong, we can break 3 or 4 belts a day. When everything is good, 50 hours should be reasonable. BTW find all the pieces of those stripped teeth or your bilge pump will at a really inconvenient time!!! Here is a pic of a guard we have built to protect dry sump belts from collateral damage. Hope this helps, Eric

Whipplecharged:

Fantastic post thanks for the explanation. Your experience in this area is extremely valuable as what you take for common knowledge is news to me and everyone else:). It also builds confidence in the product.

I know 90+ hours is a lot on a belt but figured it would snap before it turned into whopper chopper rubber salad.

It makes perfect sense now. I hit the rev limiter doing the fly bye's kinda hard i.e...bump bump usually it is gradual to the limiter or just before it I back out.

The above is what I do the belt twist is new to me but makes sense.

I think 50 to 60 hours is going to be my service interval as I boat 100+ hours a season. This will allow me to change the belt mid-season and then have a new one until the season ends.

Ok! thanks I feel much better now as I know what to expect. I graduated from a 3.3litre Whipple which is an excellent product to the 8.3 which is whole different animal/monster in making HP.

FYI: I highly recommend/love the 8.3litre Whipple unit it puts out monster HP depending on the set-up from pump gas to race gas. Low profile fits under my hatch and virtually trouble free...knock on wood:lolhit:.
______________

Boyd:

I think your right on the money about the idler pulleys my port one is a little sloppy and it probably needs a shim. Now the idler bearings do you lube them with anything or are they kept dry. I do not lube them at all is this a mistake. I figured it would all fling out anyway.

Whipplecharged this would be good information to find on your website. Recommended service interval for belt and idler alignment and/or bearing replacement for the idler/tensioners. Any thoughts?

Boyd... I'm headed to the boat here shortly with standard belt in hand and I am really dreading the mess. I'm way ahead of you on the rubber in the bilge somehow it will get past that screen on the pump even if it is just a small little nodule and jam it up.

I'm gonna vacuum the hell out of the engine compartment/bilge.

Thanks again Whipplecharged for the excellent feedback it is much appreciated.

KAP

P.S. The drag racing metaphor of the snake coiling refreshes my recollection I know exactly what your talking about now.

P.P.S. Also Boyd your not the only one overdriving their Whipple to such a degree:drink: good to know I'm not the only one.

What about a cog belt?