Last year I asked everyone to help me choose some oil for my lawn mower just bought. I choose Tesco universal synthetic which now is a silly price ( was £10, now £23 ). B&S seem to have gone OHV so I gambled that modern oils would be OK. I think lawnmowers harder to classify than F1. 1992 xxxxx engine that could give 2000 bhp is if asked for a few laps ran on standard supermarket oil now not recomended for even old cars. I must not give the whole story here. It is very interesting and alas would get me into trouble. I still would say F1 easier than lawnmowers.
My reference book is called " Lubrication . A Tribology handbook " M J Neale . ISBN-0-7506-0882-A . It is by pure chance published 4 miles away. £25 was a very good price for a low publication book. It is a gem. It is very easy to understand.
My reference book is called " Lubrication . A Tribology handbook " M J Neale . ISBN-0-7506-0882-A . It is by pure chance published 4 miles away. £25 was a very good price for a low publication book. It is a gem. It is very easy to understand.
OHV = Overhead Valves?
As opposed to OHC = Overhead Camshaft.
I suspect even the lawnmower is subject to pollution control now? The engine never seen is OHV with same cam to valves as injectors for a diesel engine in cars. That would be as 1960's locomotives ( BR type 47 for example in common rail ) . Direct injection and no belts. Side valve will not allow optimum burning due to compression ratio verses valve lift compromises. The OHV is the least compex engine for most advantages. Up to 8000 RPM it is not a bad choice. If hydraulic tappets it is almost maintainance free. The Triumph twin being exactly how best to do the job or BSA even better as single rail. The Triumph used dry sump which can give slightly more power as long as oil squiters are added to repalce lost oil splash of a wet sump. Some wet sump engines have baffles to assit going uphill, again dry sump better although most are wet. The dry sump usually has a pump capacity of 150% to scavenge the oil in the sump. Triumph used a Pilgrim pump of beautiful simplicity. Carry a small punch and hammer in the tool kit to reseat the pumps balls. If a filter fitted that is unlikely to happen. You know if it is wrong as the bike ejects oil through the breather at about a pint a minute on start up usually. Triumph had a very simple oil presure indictor at the crank shaft end. A peg that comes out about 5 mm if all is OK. I have never known a Triumph fail due to oil problems if holes checked when rebored, simple and reliable. The oil they liked was BP Super Viscostatic 10W50. Purests used Texaco SAE 30 ( and 20 or 50 ) as did Ducati. Piston rings cause most of the problems, even oil leaks due to crankcase presure. I am told VW petrol engines no better.
Nige, I don't know about diesel engines, but regardng petrol engines, OHV was never as effcient as OHC, let alond DOHC 4 valve per cylinder engines, with cam opening variators (which are meaningless only in turbo assisted engines). Getting engine efficiency of sa 80 hp/litre with OHV engines is not easy at all.
I hear a lot of people cryng for the good, old days of big bore short stroke Italian type engines (e.g. Fiat's 80.5x55.5mm 1116 cm3, 80.5x68 mm 1296 cm3, etc) which were made to tune, due to extremely short stroke, even at mad RPM the length of way was very small even at very high RPM. This general type of engine was buried by emission regulations, since companies soon discovered that smaller bore and longer stroke engines could be suited for emission laws much more easily. Current modern cars, e.g. Honda's current new 2 litre engine are 81x92 mm versions, at still healthy 6.200 rpm. Good for Euro 6 regs.
I hear a lot of people cryng for the good, old days of big bore short stroke Italian type engines (e.g. Fiat's 80.5x55.5mm 1116 cm3, 80.5x68 mm 1296 cm3, etc) which were made to tune, due to extremely short stroke, even at mad RPM the length of way was very small even at very high RPM. This general type of engine was buried by emission regulations, since companies soon discovered that smaller bore and longer stroke engines could be suited for emission laws much more easily. Current modern cars, e.g. Honda's current new 2 litre engine are 81x92 mm versions, at still healthy 6.200 rpm. Good for Euro 6 regs.
That's a side valve arrangement.
not an overhead valve arrangement.
Many pre-second world war vehicles had this and those that carried over until newer designs were ready for production still used this until the 1960s.
Somewhat oddly OHV and OHC and double OHC already existed in the 1920s but seemed unpopolar for series production.
It's not about efficiency.
The comparisons you are trying to draw are about rev ability.
OHV can give >100hp/litre, cf Clubmans racing class.
But this is at high revs where OHV technology is near it's limit. The life of the valve train will be relatively short.
OHC can be designed to rev much higher and still retain a long life expectancy.
efficiency is very different
I think you would be surprised. OHC when 4 valve and twin cam might have an advanatage just due to better layout angles. Unfortunately that will not be a for saving fuel, side valve neither. Kawasaki had the very best Bmef ( Brake Mean Effective Presure ) in their OHC two valve engines right upto when polution became the issue. The disadvantage with OHV is price. OHC is cheaper, not least if Honda make it. They perfected using the aluminium without shell bearings for the camshaft. Some Honda engings use leaf springs for the valve. Mr Honda himself designed them. CB450 was the famous one.
Desmodromics are nice. The spring can be very light weight as the lever closes the valve. For this you need OHC. All OHC advantages come in at 10 000 RPM. Short stroke also. Mr Honda said if an engine can do 20 000 RPM the pulsation in the inlet stops. The engine becomes continuous flow. A bit like a fire storm. I am sure not if corrrect. None the less engineers believe it true. F1 nearly could do that when the V10. Air desmo.
Very long stoke engines are the better choice. What they might not give is the last word in BHP. The French tax system enouraged this as FHP tax as based or bore size. 2CV mostly was the barrel bore. I think Citroen found out is the 1920's that a 330 cc square is the optimum barrel size. If you think about it still ture today. 3300 cc V10 4 litre V12. 990 cc 3 for a motorcycle.
BR 47 Loco from memory had 850 RPM as tickover and 1050 RPM max. All the power came from forced induction and Star/Delta windings on the motor generator sets. The jet like whistle was the turbo. Comsuption was better than 2 UK gallons per mile, not bad when the EE shunter doing 15 MPH at two miles per gallon. UK gallon is about 4.6 litres. With a type 47 you only need 100 passengers to beat one man in the better cars. The average aircraft can do that .
Desmodromics are nice. The spring can be very light weight as the lever closes the valve. For this you need OHC. All OHC advantages come in at 10 000 RPM. Short stroke also. Mr Honda said if an engine can do 20 000 RPM the pulsation in the inlet stops. The engine becomes continuous flow. A bit like a fire storm. I am sure not if corrrect. None the less engineers believe it true. F1 nearly could do that when the V10. Air desmo.
Very long stoke engines are the better choice. What they might not give is the last word in BHP. The French tax system enouraged this as FHP tax as based or bore size. 2CV mostly was the barrel bore. I think Citroen found out is the 1920's that a 330 cc square is the optimum barrel size. If you think about it still ture today. 3300 cc V10 4 litre V12. 990 cc 3 for a motorcycle.
BR 47 Loco from memory had 850 RPM as tickover and 1050 RPM max. All the power came from forced induction and Star/Delta windings on the motor generator sets. The jet like whistle was the turbo. Comsuption was better than 2 UK gallons per mile, not bad when the EE shunter doing 15 MPH at two miles per gallon. UK gallon is about 4.6 litres. With a type 47 you only need 100 passengers to beat one man in the better cars. The average aircraft can do that .
@Nigel: You are confusing a number of different things there and sounding like 'the man in the pub'. I know you know more than that!
Pop quiz: the ford 2litre duratec engine can make >100HP/litre with nothing more than a Cam swap and free flow exhaust (and of course ECU program). Why would Ford make the rep mobile engine breath so well?
Pop quiz: the ford 2litre duratec engine can make >100HP/litre with nothing more than a Cam swap and free flow exhaust (and of course ECU program). Why would Ford make the rep mobile engine breath so well?
We are not allowed to talk cars so lawn mowers has to do. I guess type 47 loco's will be banned anon.
I did a serrious stydy of side valve engines. Alas they can not get around their problems. I took it as true as it seems counter intuitive. Conjecture. Piston has the squish or whatever. Head is flat except valve pocket. Surly if blown it will work ? Prime interest diesel. Remember the combustion takes place after the air is thrown in. The injector could be where ever suits best into the piston cut outs/swirl chamber. OK the valve lift might be less than ideal. It is a problem if the blower is < 1 bar. Even a simple blower is 4 bar. 0.9 bar is often all that is needed. A compression ratio of about 17 to 1 should be ideal. The idea is a dead simple engine of good output (>120 BHP 3 litre 6 cylinder ) that can mostly rebuilt in an afternoon. No cambelt and very simple. Sophisticated injection I would allow. Clutch also a 2 hour job.
My oncles friend was Harry Weslake, both living in Tram Road Rye. Frank had Tram Road built . Harry and Frank made tractors. Harry was a gas engineer who used gas measuring tools to improve engines. As far as I know he invented gas flowing. His idea is an ideal engine is also an ideal compressor. His kidney shaped OHV cylinder head used on the Mini. I never met Mr West as my mum insisted on calling him. Shame.
The man in the pub is to get people talking. I often get things wrong, the risk is worth it. If not the subjects get so dry. Very often a pearl comes out.
I made a phase plug with a 4 inch gloss paint roller. Funny how it takes away the verve sometimes. Mostly a good move and $2 a piece. Held by 1930's style spring curtain track passing through a drilled hole and fix with curtain eyelets to the driven unit screws. Black 1/4 inch heat shrink to make it look good. I minute to remove if a better idea comes to mind.
I did a serrious stydy of side valve engines. Alas they can not get around their problems. I took it as true as it seems counter intuitive. Conjecture. Piston has the squish or whatever. Head is flat except valve pocket. Surly if blown it will work ? Prime interest diesel. Remember the combustion takes place after the air is thrown in. The injector could be where ever suits best into the piston cut outs/swirl chamber. OK the valve lift might be less than ideal. It is a problem if the blower is < 1 bar. Even a simple blower is 4 bar. 0.9 bar is often all that is needed. A compression ratio of about 17 to 1 should be ideal. The idea is a dead simple engine of good output (>120 BHP 3 litre 6 cylinder ) that can mostly rebuilt in an afternoon. No cambelt and very simple. Sophisticated injection I would allow. Clutch also a 2 hour job.
My oncles friend was Harry Weslake, both living in Tram Road Rye. Frank had Tram Road built . Harry and Frank made tractors. Harry was a gas engineer who used gas measuring tools to improve engines. As far as I know he invented gas flowing. His idea is an ideal engine is also an ideal compressor. His kidney shaped OHV cylinder head used on the Mini. I never met Mr West as my mum insisted on calling him. Shame.
The man in the pub is to get people talking. I often get things wrong, the risk is worth it. If not the subjects get so dry. Very often a pearl comes out.
I made a phase plug with a 4 inch gloss paint roller. Funny how it takes away the verve sometimes. Mostly a good move and $2 a piece. Held by 1930's style spring curtain track passing through a drilled hole and fix with curtain eyelets to the driven unit screws. Black 1/4 inch heat shrink to make it look good. I minute to remove if a better idea comes to mind.
You are forgetting scavenging and volumetric efficiency, both of which a sidevalve (flathead to our cousins across the pond). sidvalves are great when you have to decoke every 3000 miles not good when you want power. OHC allows a pent roof which gives a great combustion area, good fuel mixing and excellent scavenging. An engine is a tuned system after all.
I love big diesels. Deltics cos they are so bonkers in concept and the valencias that used to be in our High speed trains. Who couldn't love a 90 litre V12!!!
I love big diesels. Deltics cos they are so bonkers in concept and the valencias that used to be in our High speed trains. Who couldn't love a 90 litre V12!!!
Yep, that's where you get with this.
Never believe what people tell you. Someone said the Napier Deltic engines were rebadged Junkers. This is not true. They do progress Junkers types. The Deltic engines were not popular with BR because Napier supplied power packs and didn't encourage BR fiddling with them. Bewdley has a Deltic. The engine room is spotless and the engines in white ( 2 ). What a work of art this two stroke diesel is. The crank is interesting. The sound is wonderful. Diesel over Steam except LMS 8F ( I want one of each please ).
https://www.youtube.com/watch?v=HEpqrVpH890
Never believe what people tell you. Someone said the Napier Deltic engines were rebadged Junkers. This is not true. They do progress Junkers types. The Deltic engines were not popular with BR because Napier supplied power packs and didn't encourage BR fiddling with them. Bewdley has a Deltic. The engine room is spotless and the engines in white ( 2 ). What a work of art this two stroke diesel is. The crank is interesting. The sound is wonderful. Diesel over Steam except LMS 8F ( I want one of each please ).
https://www.youtube.com/watch?v=HEpqrVpH890
(But a Briggs & Stratton lawn mower is a car, a 100 year old one. Including the relic side valve engine)
Given that mowers have to work at a single operating point (well 2. Idle and mow) whilst running with 9 year old dregs of sump sludge 100 year old tech is not a bad starting point.
Aside: After 15 years of abuse the spark plug on my honda 535 broke. Discovered that some left over plugs from the mazda 13B rotary I had fitted. This was a very non stock engine so I have race gapped high temp plugs in a mower. Still starts first pull. same could not be said for the 13B!!!
Aside: After 15 years of abuse the spark plug on my honda 535 broke. Discovered that some left over plugs from the mazda 13B rotary I had fitted. This was a very non stock engine so I have race gapped high temp plugs in a mower. Still starts first pull. same could not be said for the 13B!!!
Thanks fellows, for the intro to the Deltic, I've been having a bit of fun looking around - these are a couple of choice videos I came across:
https://www.youtube.com/watch?v=E2F2qsRZ06k
https://www.youtube.com/watch?v=V8dJrnADE4Q
https://www.youtube.com/watch?v=5omgoWuXl6c
Lovely stuff,
https://www.youtube.com/watch?v=E2F2qsRZ06k
https://www.youtube.com/watch?v=V8dJrnADE4Q
https://www.youtube.com/watch?v=5omgoWuXl6c
Lovely stuff,
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