ACCO 510A PERFORMANCE ISSUE

Lang wrote: With the 7.50-17 tyres the speeds are:

4.3 Diff
100kph 2627rpm
80kph 2102rpm

With the .73 overdrive
100kph 1918rpm
80kph 1535rpm

Lang

And those last figures Lang show the problem

Way out of were it would be comfortable

Even modern (2007) cars like my dunny door ute are really geared I feel to high as as soon as it hits any type of hill it drops a gear on the automatic

Im no expert at all on IH 345 motors but 2500 I feel would be comfortable

Paul

Hi Lang,thanks for your efforts. You are right,it is too high .I didnt manage the maths in the first place.
I have done this calculation over and over but cant see where the error is. Grey matter problem most likely.
International 510Aa Drivetrain Calculations
Tyres 750/17
Tyre Diameter = .82 metres
Circumference = 2.57 metres (Pi D 3.14 X .82 = 2.57 metres)
Diff Ratio 4.30 (PLATE)
At 3700 rpm (in fourth gear/direct) divide by Diff 4.3 gives axle speed of 860 rpm X 2.57mtrs (Tyre Circumference) is
2.57 X .860 mtrs = 2210 mtrs a minute (2.21 Kilometres) x 60 = 134 Kph Mmm? scary,something not right.
This truck tops out at about 3700rpm @ 80 kpm.
What do you think if I swap it for a 5831 with .85 overdrive. 80 kph plus 15% is 95 kph or am I dreaming.Thanks mate.Regards Abbuss

Thanks Wannabe, sorry I am having a few difficulties with messages on this site.You are right I thought lack of power might have been a tuning or carb problem but the're ok. I guess there is no other solution but go for a lower ratio.Thanks for your input.Regards Abbuss

Thanks John,that is interesting, would you be running a Fuller 5 speed overdrive or something .Mine has 17'' wheels.Many thanks .Abbuss

Thanks Lang.So according to your figures with the T 17 4 speed direct to the 4.3 diff it should do 100 kph at 2627 rpm. .Abbuss

My 1310 has a 354 Perk ,and as I mentioned ,does 100kph at 2800rpm (direct T17 to 4.3)......obviously approx ..........one thing to remeber is to measure the rolling radius from road /concrete to hub centre ,and use that.......the other thing using figures is they are for new tyres .......my old 1310 would not have known a new tyre ,ever.....I used it 20 years ,only truck I ever wore out (still in the yard,rusty).....it was great little truck ,and only too high geared was starting off with about 3 to-4 ton on it ,on a hill .....once moving ,all you had to worry about was stopping.....which was a lot more of a worry than the gearing.

Your only options with the axle fitted would be 4.88 and the 6.16 ratio from the front of a 16004x4..............with a 1600 axle ,basically you only got one option 6.16 ,or slower......The 4.88 in the IH axle was from the old days ,and was also used in the 4x4s,and is very subject to breakage ...the 4.33 has much bigger gears with coarser teeth ,and was designed to beef up the diff in the 1500s.

Here you go. This calculator saves the old brain.

When they say third gear they mean 1:1 direct drive. Ignore their 5 speed box as this relates to a particular gearbox. To work out the gearing for an overdrive just divide your diff ratio by the overdrive reduction and put the answer in the diff ratio box.

Changing tyre sizes does not make a huge difference (at least when compared with changing diff or overdrive ratios) nor does worrying about flat or worn tires. Any tire web site should give you tire diameter for your particular chosen size.

You can leave any box empty, if you know the others, to get the answer for ratios, tyre diameter, RPM etc

spicerparts.com/calculators/engine-rpm-calculator

First thing I think of when a 345 V8 lacks power is a dud sparkplug ....its quite difficult to tell if the motor has a bit of a miss ,so replacing plugs ,points ,and capacitor would be the first thing I d do .......second would be to see if it has a too big aftermarket carby thats jetted wrong to compensate.......Ive had several in trucks ,and IMHO ,they pull strongly from 1800 revs.,including one in a ACCO bogie tipper that used to work real hard ,and had masses of blowby....the one in the AB180 in the yard had no trouble handling a bogie trailer with 20 ton on,it was ex RAAF and like new when I got it......Replaced with a Perk many moons ago.

Abyss, not to confuse you anymore but the website is SPICERs you only need you gear ratio and the height of your tyre and what speed in mph and it will give you the revs from your input,