Petrol through Eaton supercharger?

[sonus]

I am considering supercharging my Daimler 2.5 v8 as it will probably end up being just as expensive as getting 4 double barrel down drought carbs.

It looks like an Eaton M62 would fit nicely. I plan to stick with a carb, possibly a large Weber DCOE, to feed the charger and engine. However I think I read somewhere that these Eaton superchargers don't like to be a fed a petrol and air mix due to some coating of the supercharger vanes? Am I right or will it pose no problem?

Would it be difficult to tune a DCOE or similar from Dellorto to give correct mixture when air is being drawn through it by a charger or would I jet is as if it was just a bigger displacement engine?

[Woofwoof]

Any M62 I've seen was set up for air only but of course they've all been on injected engines. I'd also say the M62 was probably only designed with EFI in mind. Regardless, I can't see the M62 bearings & seals being designed to take air & fuel. I think it would be advisable to fit an intercooler (as they do suffer from heat soak) thus it would be more practical I'd presume to feed the carb boosted air. Just my 2p's worth.

[sonus]

I found the info about not feeding them air/petrol mix and it is from Eaton/Magnusson directly. However I've seen a few used this way and with the car covering only 5000km each year It'll probably take a decade before the seals and bearings let go(?). Also found this victorylibrary.com/supercharger/super-eaton.htm

Fitting the carb as a blow through isn't really practical as I'd fit the charger in the V with the carb facing rearwards and the charger output blowing down into a plenum feeding each intake runner. Possibly I could squeeze in a charge cooler, but I'll try without as I am max going with 12psi boost (158cubic inches engine with the 62 cubic inch charger geared max 2.3:1).

[sonus]

Like this

[sowen]

There's plenty of builds where the Eaton supercharger is used to suck through the carb, just that it isn't recommended as the fuel mixture can damage the rotor coatings I'm led to believe.

I have to ask, would a single Weber be capable of flowing enough air/fuel to feed the engineas the revs and boost goes up? 12psi on a 2.5 is a lot of air.

Have you thought about fuel injection?

[Woofwoof]

Sonus, I understand you wishing to mount the S/c in valley of the V8 with the carb mounted directly to the S/c as per your photo, makes a lot sense from a packaging perspective but really I'd imagine going EFI and using an intercooler would be the ideal way. Regardless, keep us posted of your progress.

[adam73bgt]

The supercharger kits for MGB's all use an Eaton M45 with a suck through carb and many owners seem to have racked up decent mileage with no ill effects, I think theres a guy running an M62 on an MGB in the same way too and he doesn't seem to be having issues either

[sonus]

After some more reading it might be that the lack of seals on the rotor bearings might be a bigger problem than the coating. The petrol washes away the exposed grease in the bearings prematurly wearing them out. However they are being used in the Moss kits for numerous MGs and many people have used them as I intend. Maybe the bearings can be "upgraded" to items with seals? Also due to the relative low cost of second hand units I might aswell try

Regarding fueling i'd like to stick to carbs as it is more in the period of the car (67 TVR Vixen V8 protoype) and what I think the factory might have done if they didn't go with the Ford 289 and 302 V8s. I will however need to do programmable ignition like MegaJolt or similar so might by a ECU that I can use as ignition only and then go EFI if my sentiment towards period mods changes. Would a DCOE 50 be made to flow enough?

[sonus]

And I measured the available height which is 25cm or 10" from bottom of inlet manifold flange to top of dashpot on the SUs.

Eaton M62 are 5" tall so that leaves me with 5" to make a plenum underneath the supercharger and possibly fit a charge cooler into.

Dynamo will have to be moved and the supercharger snout take its place.

Can moderne alternators be run the opposite direction and still make a charge? Reason for asking is that I might be able to fit one facing backwards in front of the engine.

[penski]

If you're looking for period mods then why use a modern supercharger?

*n

[sonus]

Oct 28, 2014 2:00:58 GMT penski said:

If you're looking for period mods then why use a modern supercharger?

*n

Good question

The Eaton M62 from a Mercedes looks "almost" like a roots blower and will perform better. The Mercedes M62 also has the inlet on the backside where as Roots type blowers usually has inlet on one side and outlet on the other making packaging difficult. I've actually got two cabin pressure Roots blowers from a DC airplane, but they are too small for my 2.5 liter V8.

[sonus]

Oct 27, 2014 11:12:35 GMT sonus said:

Like this

I spoke to the owner of the Mitchell Special running the above set up this afternoon. The car has now done some 10k miles with some racing and there is no sign of extraordinary wear on the supercharger. He was running 13 psi, but blew a hole in the block so has now reduced to 9psi and has been running this pressure for the 10k miles without problem. He is using a single Weber 40DCOE to fuel the 2 liter supercharged engine.

Looks like I might on to something here

[Woofwoof]

Sonus, if do decide to go for an M62 from a Mercedes and you don't require the electromagnetic clutch pulley I might be interested in buying it from you.

[sonus]

Oct 28, 2014 20:49:02 GMT Woofwoof said:

Sonus, if do decide to go for an M62 from a Mercedes and you don't require the electromagnetic clutch pulley I might be interested in buying it from you.

Or if you buy the charger with the pulley in the UK/Ireland I'll buy the charger ex pulley from you if you ship it to Norway

[mylittletony]

Awesome! Pleased I found this as I'm planning to supercharge my volvo 240 in the future. I plan on using a b230fk from a 940 turbo but as my car is carbed and ECU free, I'd like to keep it that way.

I was planning on ~10psi boost, possibly drawing through a twin choke weber although I was thinking downdraft instead. 200hp is my target.

Bookmarked!

[sonus]

I need to dig out my Corky Bell supercharger book from the attic

www.amazon.com/Supercharged-Testing-Installation-Supercharger-Systems/dp/0837601681

[mylittletony]

ha!! I dug my copy of this out just 2 days ago for late night reading...

Forced Induction Performance Tuning

[Woofwoof]

Oct 29, 2014 6:12:08 GMT sonus said:

Oct 28, 2014 20:49:02 GMT Woofwoof said:

Sonus, if do decide to go for an M62 from a Mercedes and you don't require the electromagnetic clutch pulley I might be interested in buying it from you.

Or if you buy the charger with the pulley in the UK/Ireland I'll buy the charger ex pulley from you if you ship it to Norway

If I come across one I'll let you know. 

[sowen]

I have a spare M62 (not for sale) which I have a plan to remove the magnetic clutch to fit a longer snout. The front cover plate on the magnetic clutch has the drive splines from the rotors, it's an integral part of the front cover assembly. A plan I had was to use an M45 front cover as that shares the same bolt pattern, only problem there is the rotor drive is completely different between the two. Not impossible but would be very involved to do a good job of. Easiest solution I came up with would be to cannibalise the clutch drive plate into an extension shaft rendering the clutch assembly rubbish

[Woofwoof]

Some of the U.S.cars are fitted with M62's, most of those from what I know have a long snout as standard. Have a search online & try eBay.com, you just might get the long snout on it's own. Worth getting front & rear bearing kit with seals too.