ph2 engine brake

[FOWLER MAN]

:? As far as I can remember all ph2s started on the crank. I would have thought a cam start would be harder as 1 turn would need to turn the crank twice.

I've been around Petters AVA, PH, PW and PJ series more than 55 years and hardly ever came across many set up to start this way.
Petters own info bears out what TC, (Tractors),stated in his post though. ( see below)

Petter cold start.jpg

All these engines properly set up would start with one pull over a compression on a warm day and I don't think waxing in the fuel has much to do with a reluctant starter on a cold day either.
A big factor which is often overlooked is usng the right grade of engine oil.

[tctractors]

Well Daz, I dont want to say it but your talking a load of crap on this item, take a very popular Dumper of the Petter Lister age, the Thwaites 2 Ton all drive, thats the dumper with the skip that would near touch the ground, articulated steering fitted with the off set engine, this Dumper sold in the 1'000s being the true site work-horse, it was firstly fitted with the AVA2 then later the PH2, it was never fitted with electric start, the starting method was off the cam at half speed, lots of other dumper manufacturers stuck with the flywheel start making them less desirable and hard to sell or hire due to their crap starting on a slightly cold day, generators water pumps and cement mixers most often (near always) sported half speed start, as already said the correct oil and the correct setting/adjustment of the de-compressor lever helped with any hand starting engine, but I find your comment ill-informed and wildly inaccurate, so please think about things or do some homework on engine construction, the camshaft runs at half the speed of the crankshaft on 4 stroke engines, this means 2 turns of the camshaft = 1 turn of the crank, this means your arm has to move faster but the load is a lot less.

I hope this bit of script helps some tctractors

[daz28]

crap? maybe your getting confused with lister but the ph2 in thwaites 4000 started on the flywheel /crankshaft. the gear box sat at the front timing gear end.

I can also remember key starting ph2's as well.

I find your comment insulting. if I was wrong then correct me by all means. but I am not wrong.
a four stroke engine has 2 cycles ( 1 cycle +1 revolution of the crankshaft) the crank will turn twice to one turn of the camshaft.
first cycle
1 compression piston rising valve closed .pump cam lifting.
2 ignition piston falling valves closed
2nd cycle
3 exhaust piston rising exhaust valve open
4 induction piston falling inlet valve open
so to start from a cam shaft means you need to turn the crank twice. the starting handle will need more force to move but will turn the engine faster.


URL of the original image: http://i916.photobucket.com/albums/ad7/dazm28/dumper%20engine/_35_zps6135020f.jpg


URL of the original image: http://i916.photobucket.com/albums/ad7/dazm28/dumper%20engine/gallery18_zpsfe161a96.jpg

[Jeremy Rowland]

Okay gents lets just calm down a bit please after all this site is about trying to help others as much as classic machinery as a hobby in general; different folk see things differently and sometimes perhaps in typing things don't come across as clearly as they could have I've done the same myself.

Jeremy

[tctractors]

Daz, I never said anything about Thwaites 4000 dumpers as for cams spinning at twice crank speed??? generator powered by Lister engines near always had the drive taken off the Flywheel end, Thwaites near always stuck with the Petter engine even in their top size dumper at the time the 3 tonner that Peter Thwaite had help from a Uni' with the design was fitted with the PJ3 with key start so no dramas with a handle, its a fact that direct start off the flywheel is harder than off the cam, how you can say otherwise is your right to do so, the key start was not fitted to the 2 ton dumper that I spoke of and is nothing like a 4000.
tctractors

[martyn williams]

:? As far as I can remember all ph2s started on the crank. I would have thought a cam start would be harder as 1 turn would need to turn the crank twice.

I've been around Petters AVA, PH, PW and PJ series more than 55 years and hardly ever came across many set up to start this way.
Petters own info bears out what TC, (Tractors),stated in his post though. ( see below)

Petter cold start.jpg

All these engines properly set up would start with one pull over a compression on a warm day and I don't think waxing in the fuel has much to do with a reluctant starter on a cold day either.
A big factor which is often overlooked is usng the right grade of engine oil.

Hello Fred
We used 10 W grade oil on the fleet of dumpers,there were over 100 in the fleet, Liner, Winget and S & P etc.I was bloody glad when the company renewed the fleet to electric start machines .A a fitter, I was called out a lot in winter time to site to start machines in cold weather.When the company took on the S & P agency the entire fleet were renewed.
Martyn

[TrevorJ]

http://en.wikipedia.org/wiki/Gear_ratio

I dare say driving from the cam allows for faster engine rotation, which is generally helpful in starting most stubborn engines by hand.

[tctractors]

I have just re-read my post on the cam to crank job perhapse I might have grasped things on this key board doggo, anyhow to clear up this item the cam start was always called the Half Speed Start, as I have already said the cam and all other drive options on near all engines are driven at half cranshaft speed, so if you turn the cam 1 rotation the crank spins 2, the fact that you are using the gear reduction within the drive makes life a lot easier on the arm also speeding up the flywheel mass to help start.
tctractors

[morrison]

sooooo back to my handbrake/engine brake problem. Here are some more photos. You can see the seal has gone on the piston. Is this a set up any of you are familiar with and can help me with.

[michigan man]

Hi your dumper is a benford TT50,not seen one
Of these for years, there is a brochure for one
In the download section
Thanks