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+--- Thread: Engine stripping (/showthread.php?tid=11961)
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RE: Engine stripping - David Taylor - 24-09-2011
I'm not suggesting that dyno checks be used as a complete replacement for engine stripdowns as there is always a margin of error. But, in response to Lee's question "Yeah, can anyone confirm that this could be accurate?", it's accurate enough to give an indication of whether further investigation is merited.
If the top 3 bikes are all within expected BHP and torque parameters, unless there's a protest, I can't see what's to be gained from stripping the motor. It's a VERY expensive process getting an engine rebuilt as it really needs substantial expertise.
Personally, I wouldn't contemplate putting an engine back together myself when I knew it had to reliably withstand up to 16000rpm and extended use in safety critical conditions. I'm certainly not capable of dialling in cams and suchlike so paying an expert to do it is the only option.
RE: Engine stripping - pat slinn - 24-09-2011
David, would you, or in fact anybody be happy to be beaten by somebody on a bike that does not comply with the regulations, if you were technically they have stolen from you the prize money. You, together with everybody else sign a piece of paper stating that your bike complies with the technical spec. It does not have to be an oversize engine, it can be illegal components inside the engine. even cycle parts !. Do people remember when Suzuki, ( Relentless ?) were thrown out of a TT race after a protest resulted in the scrutineers finding a camshaft that was not to the required spec ?. Of course everybody was in denial that they knew about this. I believe the official excuse was that the non spec camshaft had been numbered incorrectly !!!!. perhaps somebody knows more about that one ! Would the scrutineers have picked this up if somebody had not told them what to look for ?
RE: Engine stripping - Manx Mist - 25-09-2011
I heard a few years ago that there is equipment available to accurately measure bore size through a plug hole.
Stroke can obviously be measured easily this way anyway, so if this technology does exist it will save a mass of time and money.
Has anyone got any info on this? I know this doesnt address things like camshaft lift and other internal specs for supersport regs but at least it could be used for the basic capacity checks.
And thinking about it, if it doesnt already exist, it wouldnt be that hard to make such a device to accurately measure bore size, i've got a design in my head already.
RE: Engine stripping - Lee - 25-09-2011
(25-09-2011, 12:31 AM)Manx Mist Wrote: I heard a few years ago that there is equipment available to accurately measure bore size through a plug hole.
Stroke can obviously be measured easily this way anyway, so if this technology does exist it will save a mass of time and money.
Has anyone got any info on this? I know this doesnt address things like camshaft lift and other internal specs for supersport regs but at least it could be used for the basic capacity checks.
And thinking about it, if it doesnt already exist, it wouldnt be that hard to make such a device to accurately measure bore size, i've got a design in my head already.
Just asked my mate Google.
Our American friends call this a "Cubic Inch Tester." (Google it) From what I have read it's widely used on their V8 car racing.
I think it works like a compression tester. It measures the volume of air in the cylinder as the engine is turned over.
I found a guy on a forum who describes it's use:
It is basically a graduated cylinder with an indicator inside that will measure the amount of air pumped out of the cylinder through the spark plug hole when the engine is cranked over with the valvetrain closed. The temperature of the engine is measured prior to the volumetric reading as gases are greatly affected by temperature. The volumetric reading is then compared to the corresponding volume on the chart at that temperature to give the actual volume of the measured cylinder. When multiplied by the number of cylinders in the engine, it gives the total displacement of the engine. This is an effective way of measuring the engine's displacement without tearing it down.
The reason this is done is for making sure an engine is at or below the maximum displacement for certain racing classes such as stock car racing and drag racing. It is NOT done to determine the fitness of said engine.
If the volume of the cylinders from each manufacture was known this tool could be used for comparison.
YES. This would only help in the displacement rule. (just incase)
RE: Engine stripping - Malcolm - 25-09-2011
Can''t see it being a starter where testing of the modern day in line OHC or OHV engines most commonly used in motorcycles are concerned.
In an OHC engine, the cam drive (chain/gearing) would have to be removed/disconnected in order to eliminate operation of the valves, plus the spark plugs from each cylinder also being removed.
In an OHV engine, the push rods, rocker shaft and rockers would have to be removed in order to eliminate valve operation, and again, all spark plugs would have to be removed.
It's not a big step from either of the above, to actually lifting the cylinder head(s) in order to view and measure the cylinder(s).
It's most likely much better suited to the big block V8's used in drag racing for example (as you state), where these are kitted out with nitrous, turbo's, blowers etc and all of the associated plumbing.
My two penn'orth .........
.
RE: Engine stripping - Lee - 25-09-2011
(25-09-2011, 04:51 AM)Malcolm Wrote: Can''t see it being a starter where testing of the modern day in line OHC or OHV engines most commonly used in motorcycles are concerned.
In an OHC engine, the cam drive (chain/gearing) would have to be removed/disconnected in order to eliminate operation of the valves, plus the spark plugs from each cylinder also being removed.
In an OHV engine, the push rods, rocker shaft and rockers would have to be removed in order to eliminate valve operation, and again, all spark plugs would have to be removed.
It's not a big step from either of the above, to actually lifting the cylinder head(s) in order to view and measure the cylinder(s).
It's most likely much better suited to the big block V8's used in drag racing for example (as you state), where these are kitted out with nitrous, turbo's, blowers etc and all of the associated plumbing.
My two penn'orth .........
.
Of course, your right.
I got stuck in the train of thought about tools for measuring engine capacity.
Sure when the two strokes make a comeback we can explore this more in depth...
RE: Engine stripping - George - 27-09-2011
(25-09-2011, 12:31 AM)Manx Mist Wrote: I heard a few years ago that there is equipment available to accurately measure bore size through a plug hole.
Stroke can obviously be measured easily this way anyway, so if this technology does exist it will save a mass of time and money.
Has anyone got any info on this? I know this doesnt address things like camshaft lift and other internal specs for supersport regs but at least it could be used for the basic capacity checks.
And thinking about it, if it doesnt already exist, it wouldnt be that hard to make such a device to accurately measure bore size, i've got a design in my head already.
F1 have been using something similar and also at some german SB meetings, not sure of the exact equipment but have heard from many European riders that it has all but put an end to cheats.
With my engines Im not allowed to touch them, they are built and maintained by a well known WSS team at great expence. I would not have a problem with a seal being put on the engines and checked at the end of the season or at re build stage which is 1200k
RE: Engine stripping - Manx Mist - 29-09-2011
(27-09-2011, 09:29 PM)George Wrote:(25-09-2011, 12:31 AM)Manx Mist Wrote: I heard a few years ago that there is equipment available to accurately measure bore size through a plug hole.
Stroke can obviously be measured easily this way anyway, so if this technology does exist it will save a mass of time and money.
Has anyone got any info on this? I know this doesnt address things like camshaft lift and other internal specs for supersport regs but at least it could be used for the basic capacity checks.
And thinking about it, if it doesnt already exist, it wouldnt be that hard to make such a device to accurately measure bore size, i've got a design in my head already.
F1 have been using something similar and also at some german SB meetings, not sure of the exact equipment but have heard from many European riders that it has all but put an end to cheats.
With my engines Im not allowed to touch them, they are built and maintained by a well known WSS team at great expence. I would not have a problem with a seal being put on the engines and checked at the end of the season or at re build stage which is 1200k
i'm thinking along the lines of something which would enter down into a plug hole and thread wires out in possibly 4 directions to the bore wall, basically a dial gauge working through 90 degrees, although it is possible that lasers could take the place of the wire probes.
I've got a basic design sussed but i'm running out of space on the back of my fag packet here!
RE: Engine stripping - Chris Maybury - 01-10-2011
I know that it's not entering the debate but I have measured, faily accurately, the displacement of old OHV engines using a fluid.The fluid used being SAE 50 oil (To minimise leakage past the rings). The oil can be warmed a little to aid pouring and measuring, it will soon cool in the engine cylinder. This is not practical when the engine is in the bike but ok on a bench.
With the rockers, cam drive or push rods removed, remove the plug and tilt the engine until the plug hole is as near vetical as possible.
Ensure that the piston is at TDC
Using a laboratory burette, measure the amont of oil to fill the combustion space to about midway up the plug hole and record.
Move piston to BDC and slowly refill the cylinder to the same level in the plug hole and record.
The second reading minus the first, being the swept volume of that cylinder.
The effective compression ratio can also now be determined by dividing the total volume (combustion space volume plus swept volume) by the combustion space volume.
This process can be fairly accurate and I seem to remember that the late and great Phil Irving mentioning something similar in his "Tuning for Speed" masterpiece.
However the big disadvantage is getting rid of all the excess oil before running the engine.
PS For the Green or Eco minded out there, use old engine oil
RE: Engine stripping - David Taylor - 01-10-2011
This has been one of the more reasoned and informed threads I've followed in recent times and I've enjoyed the contributions by some very well respected people. In reponse to your comment (Pat Slinn) about being beaten by someone using an illegal engine, I generally try to assume that my fellow competitors are within hailing distance of the regs...;-) However, on the odd occasion when there's some doubt, the ultimate sanction of engine stripdowns still exists. BUT, the reason I wouldn't personally be too quick to use this sanction is that (i) if an engine, despite possible use of illegal bits and pieces, is producing no more torque/bhp than a well assembled legal motor, there's no advantage gained by its user/rider and (ii) I'd only advocate the use of a stripdown by officials IF the torque/bhp figures made it obvious that the engine was clearly oversize.
Like nearly everyone else in club racing, my budget teeters on the edge of insolvency most of the time. When a mandatory stripdown occurs, I usually have to concede that the season is over for that machine as I can't take the financial hit of an expert rebuild without a winter saving up for it. If I'm in that position financially, I have to assume most of my fellow competitors are similarly constrained.
The final observation I would generally try to bear in mind is that even if I bent the rules completely out of shape and used a blatantly illegal motor, there's nothing that is going to make up for the talent shortfall I'm personally equipped with!
RE: Engine stripping - ade! - 02-10-2011
anyone caught cheating should be bannned for life from wherever they are caught. oversized motors - ban the rider. blatant engine regs on a works motor then ban the manufacturer. full stop. unless you ride a honda of course :-) if you do a lap 1 second slower than somebody else on the same bike, then he's faster than you. admit it :-)
RE: Engine stripping - beepee - 16-10-2011
How times change! Does removing the head really require an expert rebuild? By gum when I were a lad it were second nature to do basic engine maintenace like taking the head off.Even on a four pot job it ain't that difficult and the only expense would be a new gasket.
I do remember a very good friend of mine being disqualified fom the MGP 250 classic for having an oversize engine by approx 1cc! However his satisfaction of not knowingly cheating and lapping at 92mph on a 250.99cc Ducati was reward enough,well almost
Hey ho,old school, old fart talking.
RE: Engine stripping - ian charlton - 16-10-2011
come on now, be fair. That would probably have given him 2 foot 6 by the end of the race. Ruddy cheat,shame he got caught
RE: Engine stripping - pat slinn - 16-10-2011
(16-10-2011, 12:41 AM)beepee Wrote: How times change! Does removing the head really require an expert rebuild? By gum when I were a lad it were second nature to do basic engine maintenace like taking the head off.Even on a four pot job it ain't that difficult and the only expense would be a new gasket.
I do remember a very good friend of mine being disqualified fom the MGP 250 classic for having an oversize engine by approx 1cc! However his satisfaction of not knowingly cheating and lapping at 92mph on a 250.99cc Ducati was reward enough,well almost
Hey ho,old school, old fart talking.
I watched the factory mechanics, ( sorry, technications, I learnt in the IOM this year that mechanics, are now techniciations !) strip the Honda motors. There was no mystery to it at all, just using a normal looking tool kit. Rebuilding it did not seem a mystery, a few gaskets and common sense. It makes me wonder weather some of to days riders only want to race their bikes, and do not, and do not have a clue regarding the maintainance of them. Surely not rebuilding your own motors ( and bikes) takes a awful lot of pleasure out of racing them.
RE: Engine stripping - ian charlton - 16-10-2011
Yes Pat, i,m afraid it,s technitions in all walks nowadays. I took my DAF in for an abs fault expecting to see mechanics,fitters, in boiler suits with mucky hands to repair expecting a bill of maybe 2 to 3 hundred quid. What i got was service technitions dressed like they were going for a night out,dressed to the dabber, and a bill for 3016.00 quid. The abs worked and passed the mot, 3 weeks later packed in again. Then took it to local garage with fitters with mucky hands,oily boiler suits,cost 98 quid plus vat, and yes it,s still working 3 years later. I,d rather watch yourself and Steve Wynne pull a motor to bits anyday. Technitions Bol ks.