M20 Dreaming

[Terry Oxandale]

I agree on the need to get this "right". I know I moved mine around quite a bit, and tried various things before I was able to confidently know I could close the rear hatch without hitting any portion of the motor or its ancillaries. I also had to ensure I could get to different parts of the motor for maintenance and service. The inverted Porsche T/A made up my mind on much of that, which only left the choice of choosing the lowest profile dry sump pan. When you've got a rear hatch that must fit very close to the motor, it doesn't allow much flexibility.

 

[Leon]

Hi Jac / Terry, I was going to look for a Jappa ring gear that was around the 10" diameter and most of these use the Hitachi geared starter motor so they have plenty of grunt in a compact unit. I even toyed with the idea of not running a starter at all so I could make a small flywheel and run the 7.5" triple plate clutch, then use a remote starter on the back of the gearbox like the Indy and F1 cars do. The only issue is if you stall or spin off and don't keep the engine running its a pain having to get a tow or someone to come out with your starter pack. To get the engine low enough I will end up with 5" from crank centre to Bottom of sump. A question for you guys, If I was to run a wide full length sump such as they use on boat engines, baffled and trap doors would it be possible to run a wet sump that shallow. I know you guys are going to say " WHY !!" the short answer is cost. The second is I don't want anything belt driven off the front of the engine, I'm going to run the fuel pump off the cam and water pump off the crank the same as they do on sprint cars. I may run the water pump off the cam as well, there are water pumps that you can run the fuel pump as well. Sprint cars also run the dry sump pump off the cam with the fuel pump but I don't have that much room unless its only 2 or 3 stage oil pump. My other thought was an internal dry sump system, Barns used to do them and they are a very simple 2 stage pump, 1 scavenge to the tank and 1 suction back to the engine. Interested in your thoughts, Please don't shoot me for my out of the box thinking. cheers Leon

 

[Mesa]

Hey Leon,
Why not a remote mount electric water pump? You can put them anywhere, I wish I would have used one in my build.

 

[Leon]

Hi Rob, good to hear from you, I have thought that as well the issue there is no alternator, How much power do they use?? I was at a Classic meeting a while back and checking out F5000s noticed 1 that was not running a Magneto but normal dissy. They said they just ran as a total loss system and the battery lasted a whole race but if you were running an electric water pump as well I wonder how long before the battery loss charge and the engine started to miss fire. All things I need to do more research on, there is of course HP to be had with non engine driven pumps.
How is you SLC coming along, haven't seen anything for some time. Cheers Leon.

 

[Mesa]

Don't know how much power the pumps use sorry. Some endurance race cars run the alt off one of the halfshafts maybe that would work for you, plus it looks as if it belongs on a race car, even if not that car. I am of the mind I want the least amount of at track pain, must be able to start the car myself with a little extension of the index finger.

I have a great story on my blind introduction to race bike 'total loss' systems, what a painful lesson, but that as they say is for another time.

Keeping my nose to the grindstone, not the keyboard. Interesting topic yours, as I am working through a starter issue that is not going away, then it's real close to firing. I think. I hope.

Cheers

 

[Terry Oxandale]

May I ask why you don't want to run anything off the front of the engine? Is it a space or room issue, or lack of access for servicing?

I ran a total loss system for a number of years, but it became a pain to always recharge the battery. I was using a belt-driven water pump at the time, and only a single fuel pump. Yes, the battery lasted well enough through the length of the events, but needed a good charge in the end. I eventually installed a single-wire off the driveshaft just to ensure I could start the engine if it stalled near the end of the event.

 

[Jac Mac]

Why do people think boat sumps/pans will work on cars? they dont, boats are like aircraft and bank in toward the turn which tends to keep oil in the pan, cars lean away from the corner and the oil wants to climb out, totally different with all the G forces working against you, while Ive built pans such as you describe they are always on the edge of disaster and with the lateral grip you 'should' be able to acheive on this car the dry sump is a must have.

 

[Leon]

I hear what your saying Jac, just researching options at this point. have you had anything to do with the "insump" systems like the Barn's System I nearly bought one from Steve Hildred some time back to put in my 4x4 Comp truck, he had it in his Monaro that runs in the "Muscle Cars".
Terry the main reason is simplicity, I like the clean look and "Nothing to fly off" idea, also there isn't a lot of room in front of the engine. If I use a mechanical water pump and a Mag then it just leaves the oil pump to drive. Thanks for the input guys.
Cheers Leon

 

[Jac Mac]

The Barnes system you mention wont gain you any ground clearance as it is two pump sections stacked ( 1 pressure/1 scavenge ). It also loads up the dizzy/pump drive gear by whatever loads the scavenge pump incurs, not a good feature. Why not simply cut an alloy engine mount plate for front of block and extend it sideways to allow all pumps / accesories etc to mount on that.

 

[Terry Oxandale]

Terry the main reason is simplicity, I like the clean look and "Nothing to fly off" idea, also there isn't a lot of room in front of the engine. If I use a mechanical water pump and a Mag then it just leaves the oil pump to drive. Thanks for the input guys.
Cheers Leon

The reason I ask is that the set-up I'm using is a single, very small, serpentine to the alternator (no pulleys or idlers), and a cog-belt to the dry sump pump. It is all very close to the firewall, which is what I wanted, and it is all easily accessible from under the car. This is about as compact as it gets. This then would allow you to use an electric water pump.

 

[Leon]

It appears that no matter what, I will have to bite the bullet and spend the money on a dry sump system if I want this engine low in the car (which is a Must) as for the water pump, I'll do the research on Mechanical, I definitely don't want an alternator. I will check out some sprint car set up's and see if they will fit. I may have to belt drive the oil pump, Thanks for the input guys. I have been in the workshop the last couple of days finishing the gear box mould, I'm really pleased with the end result should get some paint on it soon so will put up some photos. Cheers Leon

 

[John]

Leon I used an alternator off a Daihatsu Charade, tiny little thing and just managed to squeeze it in with about 5mm to the chassis tube, didn't bother with adjustment just found a belt exactly the right length.
and electric Davis Craig pump is the go, in the 5000 it sits behind the seat, out of site out of mind, and no heat sink worries.

cheers John

 

[Keith]

Why do people think boat sumps/pans will work on cars? they dont, boats are like aircraft and bank in toward the turn which tends to keep oil in the pan.

Picky corner. Only in a planing hull Jac. A displacement or semi displacement hull will lean outwards.

 

[John]

Bike engines in cars are another case in point, some people just can't or wont understand why the bike sump wont work on a track car.
Me, dry sump every time. its cheap insurance.

cheers John

 

[Leon]

Thought I'd put up some pic's of the T/A case mould. I have painted it with a sanding filler so once it is hard will sand it with some fine grit paper to get a nice finish then paint it with a 2 pack paint for durability. I have to talk to the foundry as to how they want to cast it. There is a bulge on the right side for the reverse idler so it makes it just that little bit harder. The company I use do the Cases for Hollinger and Other after market company's so I'm sure this will not be a challenge for them.

 

[Russell]

Leon
For my small penny`s worth, I used the same Daihatsu alternator that John mentioned on a snake belt that drove both the alt. and water pump. This time it will also have a small Daihatsu alternator and a Craig Davies water pump which is mounted away out of the engine bay.
Cheers
Russell

 

[Leon]

More time spent on the T/A pattern, I had it split down the middle by a local mill that has a huge band saw I put it in a frame so it could be held properly and run through true and square. I then hollowed out the diff section leaving ribs top and bottom, these line up with the studs that will hold the side plates and give strength and stop flex in the sides, I then put bosses in where oil will be pumped in and extracted from with the pump that will be driven off the lay shaft at the back, one will spray onto the crown wheel as it rotates away from the pinion so as not to create hydraulic pitting and one will spray onto the main gear stack it will sucked from the diff section though a boss at the bottom R/H side at the rear. There is still some matching up inside the housing to finish but it is almost there. Some photo's to look at, Cheers Leon :thumbsup:

 

[Leon]

Just a quick note, I have found a crank driven water pump, Its a boat pump and is very compact and suits 454 cid Chevy. I will be able to cam drive the oil pump and fuel pump and if I run a Mag, Job Done !! NO alternator and NO belts. :2thumbsup: Cheers Leon

 

[Rick T]

Hi Leon

Been following your thread with interest, your tackling of the transaxle and wheels in particular are very impressive !

The Can-Am McLarens are very special to me, my Father having owned and raced various models for the last 30 years. We always do all our own rebuilds and maintenance on them so I will try and help with any queries you have about the original McLaren parts.

Cheers
Richard Taylor

 

[Leon]

Back home again and back to the project. Thought I better mock up the rear suspension with the T/A pattern and B/H Pattern to make sure the wheel base is right and the top mount, links and trailing arms are all heading in the right direction. The motor needs to go forward 40mm and when I do that the rest of it lines up perfect. I also checked the track and that is on the money as well. I have a couple of little things left on the T/A pattern and then it and the B/H are off to the foundry. I have also bought a flywheel and triple plate 7.25" clutch. Some photos of the mock up to give you a rough idea of the lay out.

Leon.