63 replies to this topic

[Supercar]

I have an interesting mental exercise there. I am thinking about improving the weight distribution on my car with a transverse mounted engine by moving the engine back a little. Like on most FWD passenger cars, the engine is hanging in front of the front axle. I want to keep the axle in the same place but turn the engine around. The engine and the transmission will need to be converted to spin in the reverse direction. What would it take? I have a preliminary list here:

- Moving the firewall back.
- Moving the steering rack forward.
- Moving the timing belt tensioner to the other (loose) side of the belt.
- Redoing the water pump to still pump water, or using an external water pump.
- Redoing the oil pump (it's currently a dry sump, so no big deal).
- It's a DOHC V6 with a 1-2-3-4-5-6 firing order, so I think the cams will work in reverse.
- Redoing the crank and the cam timing sensors.
- What about the starter? Does it have some kind of thing that would prevent it from operating in reverse, like some one-way over-running or retraction mechanism??
- Replace the alternator.
- Replace the power steering pump.
- A/C pump (sorry, I just reinstalled it and I want to keep it working).
- Making sure the tranny gets the right lubrication in reverse.
- Do any engine lubricating things need to be changed?? I think the piston oil squirters should still work and all the slide bearing are symmetrical.
- Anything else that I haven't thought of?

Edited by Supercar, 16 August 2009 - 23:40.

[cheapracer]

For various reasons some engines have been reversed, BMW did it with their Daytona bikes to have the bikes torquing to the inside of the banking rather than up.

There are more complicated things possibly such as big end oil feed timing and the diff probably will be unhappy. The cam profile may or may not be symmetrical.

[gruntguru]

For various reasons some engines have been reversed, BMW did it with their Daytona bikes to have the bikes torquing to the inside of the banking rather than up.

Fiat 127/??? was produced in both rotations.

[Tony Matthews]

- What about the starter? Does it have some kind of thing that would prevent it from operating in reverse, like some one-way over-running or retraction mechanism??

I dont't think your Bendix drive would function, but I may be speaking out of my catalytic converter.

[cheapracer]

Fiat 127/??? was produced in both rotations.

Theres a few that you can quote such as Mitsubishi 4G63 and a few Hondas during their lives but I was being specific to an engine that went one way and was converted to the other way.

For whatever reason a few of the Japanese (as above) decided to put their engines facing to the right side of the car, maybe because their largest markets were LH drive and it lowered the production cost somewhere.

I dont't think your Bendix drive would function,

English maybe but the Japanese are forked.
(waiting for replies to that statement )

Edited by cheapracer, 17 August 2009 - 08:04.

[Tony Matthews]

English maybe but the Japanese are forked.
(waiting for replies to that statement )

I thought they used chop-sticks.

[Supercar]

For various reasons some engines have been reversed, BMW did it with their Daytona bikes to have the bikes torquing to the inside of the banking rather than up.

There are more complicated things possibly such as big end oil feed timing and the diff probably will be unhappy. The cam profile may or may not be symmetrical.

Ha! Just checked my old crank, and it appears to be symmetrical. Crank journals 2-3 are in the same plane, and all the oiling holes are perpendicular to that plane and drilled right through. Same with journals 4-5, and also 1-6. I could not find any rotational bias in its design.

I cannot tell about the cam profile, it's worth checking. It looks like the new firing order would become 6-5-4-3-2-1. The ignition is wasted spark type, so if I install the cam/crank sensors correctly then I wouldn't even have to rewire the coils. Nice! The diff is a Quaife helical type. I took it apart once and did not see any special washers that would affect the forward/reverse bias, so it should be okay too.

I dont't think your Bendix drive would function, but I may be speaking out of my catalytic converter.

Yep, I need to check out that Bendix more. Hope someone makes reverse rotation starters with the same tooth gear.

I need also to make sure that the clutch plate and the pressure plate works in the reverse direction. It does a little bit, else no serious engine braking would be possible, but I remember it has some flexible connecting links there that hold that pressure plate in place and work in tension and probably won't work well in compression.

Edited by Supercar, 17 August 2009 - 08:46.

[gruntguru]

Hope someone makes reverse rotation starters with the same tooth gear.

An auto electrician can probably convert your starter. I'm not an elec but I think it would only need the field connections reversed.

[Tony Matthews]

and all the oiling holes are perpendicular to that plane and drilled right through. Same with journals 4-5, and also 1-6. I could not find any rotational bias in its design.

This is something else I'm not sure of, but I think they all are (pependicular) as I can't think why they would need to be other than, and it would be more complicated to manufacture.

Yep, I need to check out that Bendix more.

Have I got something right? I feel a bit weepy...

[Tony Matthews]

I've just had a thought... I don't think your starter pinion will like meshing with the ring gear in reverse, due to the lead-in - or whatever it's called - ground onto each tooth on both gears. This is handed, and it could be difficult if not impossible for them to engage. And noisy.

[JtP1]

Changing the ring gear isn't that hard,just find the right diameter gear with the different tooth grind.

But you will need new cams and probably the belt tensioners repositioned. Though some engines are stressed to run in only one direction.

[gordmac]

Would it be any easier to reverse the rotation in the diff?

[Joe Bosworth]

Keep the engine rotating the same way and you will (obviously) have multi-speeds backwards and single speed forwards.

Just a bit inconvenient but most simply corrected by arranging to flop the ring gear of the diff to the other side of the pinion.

It might take a bit of machining but that is simple and straight forward compared with fiddling the engine to go the other way.

First ran into this 45 years ago when I changed dif ratios in my Lotus and carelessly flopped the pumpkin the wrong way in a dif housing with symmetrical bolt pattern. Fortunately woke up to it before driving the car on to the trailer.

Regards

[gruntguru]

Keep the engine rotating the same way and you will (obviously) have multi-speeds backwards and single speed forwards.

Just a bit inconvenient but most simply corrected by arranging to flop the ring gear of the diff to the other side of the pinion.

It might take a bit of machining but that is simple and straight forward compared with fiddling the engine to go the other way.

First ran into this 45 years ago when I changed dif ratios in my Lotus and carelessly flopped the pumpkin the wrong way in a dif housing with symmetrical bolt pattern. Fortunately woke up to it before driving the car on to the trailer.

Regards

Unfortunately the OP said its a transverse engine so we should assume it has spur (parallel) gears to the final drive. A (remote) possibility would be replacing the final drive gears with a chain.

Edited by gruntguru, 17 August 2009 - 11:43.

[Ian G]

In Australia in the 1960's we had the Lightburn Zeta, Motor ran in both directions,4 reverse gears. Also in the 1960/70's,exact details are hazy, but there were rumours that competitors had modified their gearboxes so that reverse was in fact 1st,officials took the stories seriously, cars had to reverse out of the scrutineering bays.

Edited by Ian G, 18 August 2009 - 00:48.

[cheapracer]

Would it be any easier to reverse the rotation in the diff?

. A (remote) possibility would be replacing the final drive gears with a chain.

Not remote at all, it's THE answer.

Edited by cheapracer, 17 August 2009 - 13:46.

[cheapracer]

In Australia in the 1960's we had the Lightburn Zeta, Motor ran in both directions,4 reverse gears. Also in the 1960/70's,exact details are hazy, but their were rumours that competitors had modified their gearboxes so that reverse was in fact 1st,officials took the stories seriously, cars had to reverse out of the scrutineering bays

My Dad was involved in the first Lightburn Zeta's, he often mentions them - usually LHAO

Many older 2 stroke engines, Villiers etc. will start backwards, sometimes a decent backfire when trying to start one is enough to do it.

[McGuire]

My Dad was involved in the first Lightburn Zeta's, he often mentions them - usually LHAO ;)

Many older 2 stroke engines, Villiers etc. will start backwards, sometimes a decent backfire when trying to start one is enough to do it.

Yep, vintage two-stroke autos (like pre-1905) can be reversed by the slowing the engine rpm down to just about zero and then yanking down on the spark lever to ****** the timing. Rather abrupt but quite effective.

When I first saw the subject line I thought perhaps this thread was about running a motor forward AND reverse, like a dirigible engine. Plain old reverse rotation, that's easy... sort of. Relatively speaking. However, I don't believe that relocating the engine from just ahead of the spindle CL to just behind it will improve the static weight distribution as much as one might think, especially in proportion to the cost and trouble involved. A bucket of Krugerrands in the trunk might be the more cost-effective solution.

[Joe Bosworth]

Grunt

You replied above, ¨Unfortunately the OP said its a transverse engine so we should assume it has spur (parallel) gears to the final drive. A (remote) possibility would be replacing the final drive gears with a chain.¨

Isn´t the final drive a ring and pinion dif?? I can´t remember ever seeing a road car that does not have a R&P except for some very old chain drive things with a solid axle.

Why do you want to fiddle with chain drives on the way to the dif? Leave the drive to the R&P as stock and flop the ring. Or is there something that I don´t recognise?? Or is rthat too easy??

Actually, talking about chain drive to the R&P, didn´t the EW Olds Toronado chain down to the geqrbox & dif? (Meaningless trivea!!)

Regards again

[Tony Matthews]

Actually, talking about chain drive to the R&P, didn´t the EW Olds Toronado chain down to the geqrbox & dif? (Meaningless trivea!!)

Yes. As it is meaningless trivea, I actually know that! Seven-row or summat chain.

...except for some very old chain drive things with a solid axle.

Notice my avatar?

Edited by Tony Matthews, 17 August 2009 - 17:32.

[GrpB]

1) You could leave the engine/trans as is, weld the diff solid, turn the engine/transaxle 90 deg and put it in the trunk (boot, whatever), make up a driveshaft with an inner CV spline on one end and a UJ at the other to a diff/axles from a 4WD vehicle up front and have someone make the tallest r&p they're willing to make. Or maybe just use large OD truck or tractor tires and live with the deep gearing, not sure what it's for.

2) Don't change engine/trans rotation, rotate the entire assembly so the valvecover(s) are closest to the ground with engine almost upside down. Work out lubrication issues.

Both are easier than getting multi forward and 1 reverse out of an existing transverse transaxle. Strange set of racing rules that this is more economical than buying a vehicle with the appropriate engine/drive configuration to start.

[gruntguru]

Isn´t the final drive a ring and pinion dif?? I can´t remember ever seeing a road car that does not have a R&P except for some very old chain drive things with a solid axle.

Transverse engine - I assume means FWD. 99% of them do not have bevel gear "ring and pinion" final drive. They use paralell shaft gears.

[saudoso]

Don't know the car neither the use, but since you even consider cutting the firewall off, wouldn't it be more effective to make it RWD? Just throw everything on the back seat?

[Supercar]

Unfortunately the OP said its a transverse engine so we should assume it has spur (parallel) gears to the final drive. A (remote) possibility would be replacing the final drive gears with a chain.

Yeah, a motorcycle chain or a V-belt like on a Harley.

I don't believe that relocating the engine from just ahead of the spindle CL to just behind it will improve the static weight distribution as much as one might think, especially in proportion to the cost and trouble involved. A bucket of Krugerrands in the trunk might be the more cost-effective solution.

I think you are right. Moving all the powertrain back by 15" would only alter the static weight distribution by 2%. I can reach that by simply modifying the wishbones and moving all the wheels forward by 2". I also have an option to do some suspension and body cutting and welding to lover the car another 2". I will need to plug in the tire model tomorrow, but I looked preliminary and it appears to be a much more effective solution. What limits my cornering right now is too much weight transfer in the front after the inside rear wheel lifts. Lowering the whole car as much as possible would address this more directly. Although I am sure a more rear-weight biased car would be more fun to drive.

[Supercar]

Don't know the car neither the use, but since you even consider cutting the firewall off, wouldn't it be more effective to make it RWD? Just throw everything on the back seat?

Naw, that would become a completely different car then. I do not want to design a new car out of less than optimal components. I just want to improve what I already have and what already works fairly well.

[gruntguru]

Although I am sure a more rear-weight biased car would be more fun to drive.

You will lose a fair bit of launch traction although loweing the CG will hep alleviate that.

[Supercar]

You will lose a fair bit of launch traction although loweing the CG will hep alleviate that.

This is an AWD car.

There is still a way to bolt on a transfer case to the tranny, even if the engine is turned around.

[Peter Leversedge]

Seems to me to be a lot of work to gain so little!!
PS go buy a rear wheel drive car

[ray b]

IF THE CAR MOTOR IS USED IN BOATS
THEN ALL THE BITS ARE ON A BOAT DEALERS SHELF

IN the USA most boats use chevy car motors in 4 V6 or V8
BMW and volvo allso have reverse rotation motors for boats

[Supercar]

IF THE CAR MOTOR IS USED IN BOATS
THEN ALL THE BITS ARE ON A BOAT DEALERS SHELF

IN the USA most boats use chevy car motors in 4 V6 or V8
BMW and volvo allso have reverse rotation motors for boats

Cool. If I decide to go that route later I then might as well do an engine swap for a twin-turbo Chevy V8. That would be a fun car.

[Joe Bosworth]

Ray

You said ¨ IF THE CAR MOTOR IS USED IN BOATS
THEN ALL THE BITS ARE ON A BOAT DEALERS SHELF

IN the USA most boats use chevy car motors in 4 V6 or V8
BMW and volvo allso have reverse rotation motors for boats¨

Are you sure???

I am far from a boat expert but have hung around a few V8 powered ones from time to time. These have been mounted with engines both forwards and backwards. I have sons that have both front & back mounted in pleasure/ski boats and been around a few multi-hull race boats that have all rotated conventionally.

The only changes that I have seen is in the twist of the props being used.

My knowledge base is a pretty small sample but am completely unaware of anybody reversing engine rotation for boat applications. If you can point to a real life example I will want to go find one so I can see for myself!!

Regards

[cheapracer]

¨
Are you sure???

Certainly, of course. It's by far easier to regrind the cam, redrill the crank, fit external oil pump, special water pump and special ignition or magneto than just go to the boat shop and buy a prop in left or right hand pitch.









































Sarcasm is a form of humor that uses sharp, cutting remarks or language intended to mock, wound, or subject to contempt or ridicule. It is first recorded in English in The Shepheardes Calender in 1579:

Hostile, critical comments may be expressed in an ironic way such as saying "don't work too hard" to a lazy worker. The use of irony introduces an element of humour which may make the criticism seem more polite and less aggressive but understanding the subtlety of this usage requires second-order interpretation of the speaker's intentions. This sophisticated understanding is lacking in people with brain damage, dementia and autism and this perception has been located by MRI in the right parahippocampal gyrus.

Edited by cheapracer, 25 August 2009 - 12:49.

[carlt]

Sarcasm is a form of humor that uses sharp, cutting remarks or language intended to mock, wound, or subject to contempt or ridicule. It is first recorded in English in The Shepheardes Calender in 1579:

Hostile, critical comments may be expressed in an ironic way such as saying "don't work too hard" to a lazy worker. The use of irony introduces an element of humour which may make the criticism seem more polite and less aggressive but understanding the subtlety of this usage requires second-order interpretation of the speaker's intentions. This sophisticated understanding is lacking in people FROM USA and GERMANY and this perception has been located by MRI in the right parahippocampal gyrus.

[McGuire]

My knowledge base is a pretty small sample but am completely unaware of anybody reversing engine rotation for boat applications. If you can point to a real life example I will want to go find one so I can see for myself!!

Very common in twin-engine, twin-screw pleasure boats, cabin cruiser class etc: one engine standard (OE) rotation, the other reverse rotation. Which engine is port/starboard in a particular application depends on the installation orientation (flywheel situated fore vs. aft) and type of drive. The purpose is to counterpose the output torque of the two engines, just as in aircraft. In regular use, there are thousands upon thousands of American V8s, especially SBC and BBC, set up for reverse rotation. Chris-Craft, Mercruiser, etc. All the necessary parts are quite plentiful in the marine world (mainly a matter of knowing which is what) so if you want to reverse the rotation of an SBC or BBC it's a relatively straightforward matter.

[Catalina Park]

It is quite common in Detroit Diesels for marine use too.

I have run a few diesel engines backwards, you let the clutch out accidentally (thinking that you are in neutral) and almost stall the engine, so you quickly push the clutch back in. The backlash in the driveline kicks the engine back to life but why is it running so rough?
So you give it a rev and it is shaking and knocking and the oil pressure is reading zero. Then the penny drops.
It was all ok, it wasn't my own truck.

[Tony Matthews]

It was all ok, it wasn't my own truck.

That's a relief, you had me worried for a moment...

[Catalina Park]

I wonder how the air filters look when they are full of soot?

[McGuire]

It is quite common in Detroit Diesels for marine use too.

Quite so... all the original GMC (aka Detroit) Diesels were modular in design so the same basic engine could be installed front-to-back or run in either direction. (The Allison V-1710 was also laid out in this manner.) Buses with 4-71 or 6-71 engines were configured to run in either direction, depending on the type of driveline used. A pair of 12-278 or 16-278 engines side-by-side, running in opposite directions, would be a very common marine installation. On smaller craft, a pair of counter-rotating 6-71s.

However, the original GMC diesel nomenclature created some confusion. Throughout the industry, "standard rotation" is held to be CCW as viewed from the flywheel, which GMC termed CW as viewed from the front pulley. Same rotation, opposite description. So a standard GMC engine would be called "right-rotation," which was really left.

... when you buy a pair of larger outboard motors (~140 hp up) you can spec them as a matched, counter-rotating pair. Their power heads rotate in identical direction, while their lower units output in opposite (away) directions. Not as critical in lower output installations -- the difference in handling is apparent but not objectionable.

Counter-rotating engines in twin-screw boats have fallen away in recent years -- as engines have become more sophisticated, they have become more difficult to convert. Meanwhile, there are far more options in outdrive systems than in past years. Still a lot of them out there, however.

In decades past there were a number of single-engine power boats that employed automotive engines converted from standard (CCW) to CW rotation. Chris-Craft, Century, Correct Craft, to name a few... and there are still many of those around, too. Over the years I have heard many explanations as to why this was done, some of them downright convincing. Among other things, it is said that serious water skiers preferred them. Correct Craft ski boats commonly employed a single Ford V8 converted to reverse rotation.

[Tony Matthews]

I wonder how the air filters look when they are full of soot?

Er, sooty?

[Pullman99]

In Australia in the 1960's we had the Lightburn Zeta, Motor ran in both directions,4 reverse gears. Also in the 1960/70's,exact details are hazy, but there were rumours that competitors had modified their gearboxes so that reverse was in fact 1st,officials took the stories seriously, cars had to reverse out of the scrutineering bays.

I usually post on The Nostalgia Forum, but came across this thread as I have a primary interest in the World's Land Speed Record and had been looking at some information on the Rolls-Royce "R" Type V12 one of which was converted to run in reverse in Sir Henry Segrave's WWSR boat "Miss England II". This craft used two "R" Types so presuably this was done for stability reasons. However, I believe that there is still some research to be done on the details of this application.

My reason for this response is that a Lightburn Zeta appeared in shot (I think it was a car loaned by the car's makers to the film crew) in footage of Donald Campbell's 1963/64 LSR attempts at Lake Eyre. An Australian TV Producer I used to know and work with, Patrick Taggart, ex-Channel 9 and who was working at BBC South in Southampton in the '70s and '80s told me that the Zeta's makers were involved in a car sales scam that ended up with the company's backers losing a heap of money after only a relatively small number had been made. Looked a bit Citroen Ami like but not so well made!

[Joe Bosworth]

Mac & to a lesser degree. Cat,

Thanks for pointing out the twin screww applications. I guess I have only ever set foot in one such boat, (as opposed to ship).

I thought that one had both engines rotating the same way but never really bothered to go down deep enough to look. Too busy opening beer cans!!! That was definitely a cruiser so not high on my list except as a portable bar!

My sons never went to twin engines as believing that a 500 HP plus 454 BB or really hot small block gave all the necesarry performance without hauling the weight. Definitely not off-shore boats.

Thanks and regards

[McGuire]

Buses with 4-71 or 6-71 engines were configured to run in either direction, depending on the type of driveline used.

Here is one such GMC bus driveline configuration, the Spicer 45-degree angle drive. Typically used with conventional rotation (RH in GMC diesel lingo) 4-71 and 6-71 engines. Employed a 4-speed manual or Allison automatic transmission -- actually a one-speed torque converter with lockup clutch. The manual versions took considerable skill to shift properly. As the years went on, later models used 6V-71, 8V-71, and 92 series diesels. At one time the majority of city transit buses in North America were GMC.





The Scenicruiser buses that GMC Truck and Coach division built for the Greyhound Bus Lines in the '50s -- quasi-futuristic styling by Raymond Loewy with second vista level -- used a pair of 4-71 engines running through a fluid coupling. Nearly a thousand were built; later converted to single 8V-71. The bus end of the GMC bus and coach division was originally the Yellow Coach company, which GM bought into in the '20s and finally bought out during WWII. In earlier years before diesels came along, many Yellow Coach buses used Knight twin sleeve valve engines.

[h4887]

Er, sooty?

What is it, Sweep?

[Tony Matthews]

What is it, Sweep?

Can you ask Mr Corbett to warm his hand next time?

If only I had known where this would lead...

[desmo]

That angle drive looks daft, but the longer I look at it the more sense it seems to make given what they were trying to do.

[Catalina Park]

Er, sooty?

I suppose it would just suck the soot out of them when you run it the right way.

[Tony Matthews]

I suppose it would just suck the soot out of them when you run it the right way.

Until you reverse it again, and fill the exhaust with leaves and cigarette ends.

[SimonW]

Just to remind you all we have been here before
http://forums.autosp...ngine backwards

Simon

[mariner]

I have been away so this comment is a bit late.

Some engines use a cylinder to crank ofset which used to be called " de saxe" or similar. The idea was to reduce piston side thrust and so cut wear and friction.I do not know if this is still done but I would think reversing such a motor would give some nasty piston to cylinder wall probelms.

[Tony Matthews]

I have been away so this comment is a bit late.

Some engines use a cylinder to crank ofset which used to be called " de saxe" or similar. The idea was to reduce piston side thrust and so cut wear and friction.

I've seen that in model aircraft engines, sometimes the off-set is quite considerable.