New member with a few Rovers, mainly P6b

Swede · Post by **Swede** » Wed Nov 17, 2010 12:54 pm

Hi there, Greetings from sunny Sweden.
I discovered this excellent forum whilst roving the www in search of information on diy applications for the Eaton M112.

I am in the process of putting two P6b back on the road, and at the same time working on two optional engines destined to go into these cars.

The engines are;
3,5 litre Rover SD1 CR 8,25:1
Cadillac 425 (7litre) 1977, 180 hp@3800 rpm CR 8,5:1
for one of these engines i have acquired a second hand Eaton m112, but I have not yet decided which engine is the better choice.
I also have two turbochargers scavenged from 2,5 and 2,4 litre diesel engines, one Garret T25 from a nissan Navarra pickup and one Hitachi CT20 from a Toyota Land Cruiser.

Bet you have some good ideas on what should go where and how?

I have already installed the Cad 425 in a P6 body and there seems to be room enough for the Eaton without any modifications to the bonnet.

I will return with some pictures if i find out how to post them.

Cavman · Post by **Cavman** » Wed Nov 17, 2010 3:18 pm

Hi and welcome, sounds like some interesting projects you have there!

I'm sure someone who knows more will be along soon, but my guess would be that the m112 wouldn't have enough puff for a 7L lump. much more suited to the 3.5 RV8. and I know this particular blower has been successfuly fitted to rovers before.

as I said, I'm sure more info will be forth coming, just my 2 pennies

James

kiwicar · Post by **kiwicar** » Wed Nov 17, 2010 3:36 pm

Hello and welcome to the forum I hope we can help.
With the SD1, this is a good base engine for a 3.5 rebuild, but the first thing you will need to do regardless of what you use as add ons is get the CR up a bit, you probably want to be around 9:1 to start off. I am presuming you are doing a full rebuild on this engine so I would get the block decked so the pistons are flush with the top of the block, then with comp head gaskets it is just a case of skimming the heads to give the right Compression ratio.
As for for what to use as power adder, the M112 is designed for airflow requirments of an engine making about 500 bhp on 8 to 10 psi boost, the 3.5 rover is really too small for this blower, as for your turbochargers individually they look a bit small, a check of compressor maps might be worthwhile and if you are looking for only a small increase in power they mite be able to be matched.
Now for the cadillac engine, again it all really depends what you are after performance wise, I think on a mild tune on the cadillac and at low revs the M112 could be set up to give moderate boost on an engine that does not rev above about 4800-5000 revs, again about 9:1 compression and about 8-10 psi boost and a set of mildly ported heads and a mild street cam, a blow through carb of fuel injection. I wouldn't expect to get much over about 375bhp as I suspect the heads are very limmiting power wise.
Best regards
Mike

Cavman · Post by **Cavman** » Wed Nov 17, 2010 4:38 pm

there you go Swede, told you. not the last time I'll be wrong I'm sure!

I'll get my coat........

Swede · Post by **Swede** » Wed Nov 17, 2010 5:08 pm

Thanks for the input, I should have mentioned that neither project is intended for obtaining maximum horsepower, I just have this need to develop interesting projects, will settle for somewhere around 200 - 300 hp on both engines if obtainable, this will keep both me and the cars happy. I have six P6 in total and will use these to keep two cars running, hopefully for the rest of my life. One car will have Seven Litre on the rear decklid, the other probably Supercharged, that was my plan anyhow. One will be automatic, the other will be 4 speed with overdrive.

As for RV8, I have 6 engines covering most of the CR ratios (all 3,5 litre), 2 sets of SD1 heads with the larger valves and several pairs of old heads. 3 of these engines are complete and in working order 2 of these are currently installed in cars.

The Cadillac engine was purchased from a friend as he upgraded his Cadillac to 500CI (with 4-6-8 conversion and EFI running on E85). This engine is complete, I have mated it to a TH350 and will hopefully have it up and running next summer, exhaust manifolds will have to be fabricated and I will have to replace the waterpump with probably 2 electrical units as well as i need to reposition the master brake cylinder before any driving is possible, then there is an issue with the distributor being too tall at present (HEI)

If you can point me in the direction of a good place to upload pictures can post some....or you can visit me at FB?

kiwicar · Post by **kiwicar** » Wed Nov 17, 2010 6:35 pm

Hi James
you are perfectly corect in that the M112 has been fitted to the rover several times to my knowladge, just the 3.5 is on the small size, the 4L and particulally the 4.6 are a far better match.
As for suggesting the 112 on the 7L of caddy It would seem far to big as you say and if it were a 454 chevy of ford 460 I wouldn't suggest it as they are designed to make peak power in the 4600 to 5500 range the caddy lump is a different beast, they aim to make power much further dowm 3800, 4000 is normally where peak power is aimed so a blower like the 112 that feeds a 4 litre jag engine at 7500 revs will do a 7 litre at 4250 maybe up to 4500 4600 revs but really no higher.
Best regards
Mike

Swede · Post by **Swede** » Wed Nov 17, 2010 6:50 pm

Exactly what I was thinking, The Cadillac figures say 180 BHP at 3800 revs, lets assume i run the Eaton 3 or 3,5 times faster and stay with the 3800 limit, that should be within the possible range of still producing some PSI...i have always liked cars with effortless low end grunt, and the P6 is a reasonably lightweight car, i reckon it will be around 1500 KG with this engine. I will most likely have to install a Jag diff.

Swede · Post by **Swede** » Wed Nov 17, 2010 7:01 pm

The 1970 P6b...tuning carbs....both petrol tank and engine had been out of commission for many years so i had to disassemble and clean the carbs several times before things were nearing normal....daily driver in the background.

Swede · Post by **Swede** » Wed Nov 17, 2010 7:04 pm

First time in the car....I was very concerned about if the engine would fit behind the radiator as there is very little space to move anything forward...or bacwards where the steering components are. It turns out there is just enough room if I remove the water pump and make some sheetmetal adjustments to the left hand side mount for the steering right next to where the brake cylinder is mounted. I will have to reposition the master cylinder as well because of both space and heat issues, it will probably go upwards and forwards. Work will start with engine/transmission mounts and then the exhaust manifolds are next.

Swede · Post by **Swede** » Wed Nov 17, 2010 7:13 pm

This is my 1970 P6b, it currently has a 1975 P6b engine and BW65 in unrestored but good running order. I have power steering installed in this car and my plan is to fit the Cadillac 425 in it. The old skyport will be replaced with a larger fabric sunroof from some (new) Peugeot or Citroen, when one appears at the wreckers. My aim for this build is good detailing and to keep it as a pure summer driver.

Swede · Post by **Swede** » Wed Nov 17, 2010 7:54 pm

...or like this?.......
1971 TC, this car will recieve a 3,5 litre RV8 and the Volvo 240 4 speed with overdrive. All parts assembled and fabricated, waiting for Volvo bolt pattern on the flywheel and then welding the bellhousing. I might go for a slightly turbocharged SD1 engine feeding through SU´s for the heck of it. My plan for this build is decent appearance and all year driveability. (none of the cars will be a daily driver) I know the Volvo Transmission is ok up to 150 hp if treated decently and we still have no problems getting them dirt cheap in Sweden, so I am building up a stash.

Cavman · Post by **Cavman** » Wed Nov 17, 2010 11:45 pm

Cheers for the explanation Mike, makes sense to me now. as they say: "every days a school day!"

maybe one day I'll get into Fords, chevy's etc.. but I'll stick to learning about Rovers for now I think, more than enough for me to start with!

Good luck with it Swede, I'll watch any build threads you start with interest.

Post by **Coops** » Thu Nov 18, 2010 12:07 am

just edited your pics swede so they now show on the forum mate

kiwicar · Post by **kiwicar** » Thu Nov 18, 2010 6:01 am

Hi
I presume you are aware that the M112 can't be used with a draw through carb, it doesn't have the right seals in it to use it wet.
Mike

Swede · Post by **Swede** » Thu Nov 18, 2010 7:40 am

Thank you Guys for the help and input, can anyone help me calculate an estimated boost figure on 7 litre/3800rpm and 3,5 overdrive on M112? I do not want to pursue this option if boost is negligible (or even negative)
I know that the Eaton is a dry unit, The 425 has been operated on E85 with EFI and MS by the previous owner so i can use his mapping for starters if i decide to go with MS management(very likely).

The picture of engine in car was taken this summer when i had purchased another car less engine/tranny for spares, it is ideal for cutting and shaping everything around the engine. My plan is to prefabricate all fittings and fastenings so that when the engine goes into the 1970 P6b (with the mk1 bonnet) everything is plug and play.

Regds/Joakim