After Tips On Preventing Belts Turning / Flying Off

[XFGHIA747 76]

So lads as title says, how do we stop crossflow's distroying belts at high rpm, my old engine was a happy 6200 and often rolled belts iv tryed larger alt pullys heaps of different belts and have only slightly improved, my new motor is going to be around 7000rpm and can see only more problems arising..

 

So any tips on whats best for these torque monsters and pics would be great,

Gilmore drive in my aplication isnt really a option as im very limited to room in a ke70 corolla...

 

Help would be great thanks guys

[Campo 869]

Wasnt a misalignment issue with the pulley/balancer was it?

[PRO250 1,506]

A good balancer

[XFGHIA747 76]

Na no misalignment issue alway made sure that was good had a few motors do it now, speedway enginrs etc,

 

So a good balance?? That could the problem wouldn't the engine not run smoothly at 6 grand if it was flapping about on the rubber? Or I have know idea haha,

 

Any suggestions on a reasonably priced balancer, Pro

[Campo 869]

I know whenever we had speedway engine problems with that it was always misalignment. Try romac balancer?

[ando76 4,354]

Alignment is critical as is belt brand. BOSCH = Shit, Dayco = good, Gates = best.

 

Short belts are the go if you want those revs and plan to back off every now and again as the whip is what throws the belts - when they are too long.

 

A good balancer is a help although I run a street powerbond unit on the skid ute and it is happy at those revs - now that the belts are short.

 

I made a custom low mount alternator bracket and run a separate belt for it and run a dedicated belt for the water pump. No more belt flipping for me.

 

 

 

[gerg 10,871]

Did my time on Benz buses and they were forever throwing fan belts. They were long and whippy (1st problem) and the idler used to flex under engine torque (2nd problem). Shorten your belt if possible. Check your alt bracket for rigidity to make sure it isn't deflecting under load and I'd even step down the crank pulley to water pump size or smaller so the belt isn't turning so fast and expanding from centrifugal force.

[Stevemack 122]

For long belts you need to make a roller for the long belt sections to stop the vibration at high rpm.

Can you adapt a serpentine?

[PRO250 1,506]

Na no misalignment issue alway made sure that was good had a few motors do it now, speedway enginrs etc,

 

So a good balance?? That could the problem wouldn't the engine not run smoothly at 6 grand if it was flapping about on the rubber? Or I have know idea haha,

 

Any suggestions on a reasonably priced balancer, Pro

Ask jas for the part number for the ATI those boys swear by them 

 

I run a massave steel one on my big engine it never did it again. Romac's are good but they dont seem good enough to totally fix the issue, when id flash mine past 6500 it would still turn it over, but the big one with nothing else fixed the issue. But you cant buy them anymore, mines a dave adams one

[slydog 7,873]

I run a short belt to the alt only but tbh the best way to keep a belt on @ big rpm xflow is to get the whole rotating assembly balanced as a unit from balancer (ATI or Powerbond SFI unit) to flex plate.If using a manual flywheel and clutch too.

 

The rest is a band aid on a bigger problem to me.

[SLO247 1,713]

Wrong thread.

[ando76 4,354]

Gee you would be a game man to rev an unbalanced x flow to 7000 Rob.  but I agree whole heartedly.  Good balance with all the components.  Good balancer and short belts. 

 

Something that is overlooked is the balanced inlet.  I know when we put the new manifold onto my speedway engine it improved the balance of the engine at high rpm.  It is a xf crank engine and despite the balance job you used to notice when the rpm got up there.  With the balanced inlet (each runner flowed the same cfm) the engine was hitting the 6800 limiter with ease and you just didn't know you were that high.  Anyone that has revved an xf crank engine hard will know the feeling I am talking about.

 

I have also had good success with using the air conditioning alternator bracket.  It is way stronger than the non a/c bracket and picks up the water pump bolts as well as the 3 bolts to the block.  It eliminates bracket flex but still leaves you with a long belt. 

[XFGHIA747 76]

Well there ya go thats a few things to take into consideration, going buy what yous have all said are all reasons thats can cause the problem I think my issue was maybe a bit of flex in the alt bracket as I only had the normal not he a/c type,

 

Thats interesting about the runner cfm being even ando I think that in theory makes a fair bit of sence and the more even the runner lengths to give a closer exact afr to the cylinder at same speed would make heaps of difference,

[Ando81 2,949]

I've seen this on speedway engines and the lads usually make up their idler to go on the longest stretch of the belt to stop it from whipping. Don't have pics to help sorry. I hate throwing belts though, every time I thrashed the old mans edxr6 the bastard would throw the belt off and he knew I'd been thrashing it

[ando76 4,354]

Ando81 - that is why I made the custom alternator bracket for my speedway car - which now does duty on my burnout car.

 

XFGHIA747 - It is more about even cylinder flow than equal runner length.  When you have even cylinder flow - with the inlet manifold fitted - you have a happy engine.  the individual runner - multi carb/injector set ups like you see on Ken's, Sly's, Wazzy's and Jason's cars are the ultimate as they not only give even cylinder fill but even mixture which really helps build HP and torque. 

 

I was very surprised to feel the difference with the new manifold with its even flow - but I spoke with Cam and he said when he was working with the v8 supercar stuff they would forgo flow for balance.  very interesting. 

[TF_250 398]

So lads as title says, how do we stop crossflow's distroying belts at high rpm, my old engine was a happy 6200 and often rolled belts iv tryed larger alt pullys heaps of different belts and have only slightly improved, my new motor is going to be around 7000rpm and can see only more problems arising..

 

So any tips on whats best for these torque monsters and pics would be great,

Gilmore drive in my aplication isnt really a option as im very limited to room in a ke70 corolla...

 

Help would be great thanks guys

 

This is what i used to have it worked But what a mess

 

 

changed to this and what a difference. ATI 917788

 

 

 

The belt brand is a big deal with the romac but after the ati went on I could use anything. The balancers that have the belt groove on the body is the problem the harmonics go right into the belt and off she goes.  IMO if you are planing to spin to 7000 you must have a decent motor going on there so why skimp on a balancer the ati unit is around $400 from the us last time i saw the romac wasn't to far behind that.

[XFGHIA747 76]

Thanks lads one way or another i can see ill get over this with ease,

 

Ando  - once again your always a wealth of knowledge, i couldn't think how much i have learnt from all us crossy nuts on here that are willing to spill beans,

 

tf-250 - thanks for that they really look alot better being full steel and having the pully running of the centre, a small amount of time re alinging water pump and alt to run off outer and it would be great.

ill see if i can get a link up to have a good look might be on the shopping list.

 

what manual flywheels do you guys use there is a few sorts i have noticed, a mate of mine has about 5 different one all thicker and thinner then one another one he has the amount of steel on the engine side of the flywheels is as much as the clutch side, how would this good and whats the best crank for the best balanced engine, ?? 

[ando76 4,354]

Jason - did you have your ATI balancer 'balanced'?  I know they say it doesn't need it and that you have to spin them up so that they settle and then they are fine.  Cam spun mine up at the rpm they recommended to settle everything then they chucked it on the balancing machine and it needed a bit of material taken off it to be true.  Ryan's was the same??? 

 

On the flywheel subject I think the XD manual flywheel had a bit less meat in it - making it lighter - but you could take the same amount off any other flywheel and end up with the same result. 

 

What you have to realise is the weight does not effect top speed but it does effect acceleration - and at the same time deceleration.  If you want an engine that spins up quickly then less weight is the key.  That is why we fit Quarter Master 7 1/4" dual plate clutches to our speedway cars and most are now even going to the 5.5" 3 plate clutches - particularly the V6 holden boys.

 

If you are planning to go to 7000rpm on a manual x-flow then there is no way I would be using a stock flywheel - well not without a scatter shield - I like my toes on my feet. 

 

For everyday use the 7 1/4" dual plate clutch will be acceptable but you will not be able to slip the clutch.  They are either on or they are off.  If you slip them you may as well grab 3, $100 notes and set fire to them as that is what you are doing to the friction plates. They come with a drive plate (it's made for an early Windsor) and then you have to use a C4 flexplate with the centre bored out and it bolts to the drive plate so that the starter has something to engage on.  If you are interested in going this way I will post up some photos of my set up. 

 

As for crank shaft - EF if you are going to turn it that hard. 

[Thom 6,651]

If using a 4.0 crank yella terra sell billet steel flywheels for 5.0l's and get it balanced to suit 6 cylinder

[gerg 10,871]

You can get them neutral balanced already can't you Thom?

[TF_250 398]

Jason - did you have your ATI balancer 'balanced'?  I know they say it doesn't need it and that you have to spin them up so that they settle and then they are fine.  Cam spun mine up at the rpm they recommended to settle everything then they chucked it on the balancing machine and it needed a bit of material taken off it to be true.  Ryan's was the same??? 

No ati specificly state not to. They are rebuildable and that one of Ryan's I serviced, so every time you rebuild it you will have to rebalance it?? Yes?? And they way you balance your engines as a whole, won't it chage the overall balance????

[wagoon 2,429]

I believe that jason's/my balancer was only used to balance the rotating assembly back to the pressure plate. I would need to double check with Cam regarding that to be 100%. From memory even my pressure plate was not touched.

[Thom 6,651]

You can get them neutral balanced already can't you Thom?

 

Yes you can I completely forgot about that, when I got mine they were out of stock of the neutral balanced flywheels I think it cost me $40 to get it mirror balanced to my old flywheel

[ronny 204]

Are you retensioning the new belts after some driving?

Ive found new belts stretch a fair bit

[ando76 4,354]

No ati specificly state not to. They are rebuildable and that one of Ryan's I serviced, so every time you rebuild it you will have to rebalance it?? Yes?? And they way you balance your engines as a whole, won't it chage the overall balance????

Each item is balanced separately so yeah there might be a need to re-balance just the balancer after it is rebuilt. In the same way the you re-balance a new pressure plate going onto a previously balanced rotating assembly - well if you are anal about balancing like me anyway.