MPI Block questions?
Turbo Mini Forums

Got an MPI block and am thinking of buying it. Couple of questions though. I notice that the block has two pressure relief valve openings. which one is used? I use a adjustable pressure fitting if it is the lower one it will not fit cause it's behind the starter. I like the fact that the entire block is beefier but the oil system redesign has me concerned. This is for an scca type full race engine and will get the four bolt main treatment a 8 counterweight crank and abused on the track only. Not ever seeing an mpi block up close before i don't know if they have inherent problems. Should i buy it? Aaron

Racecar spelled backwards is Racecar

The top hole os for an oil temp sensor. I use a standard relief valve nut drilled and tapped to take a mechanical oil temp gauge, its the same threads. This is the main oil feed from the pump to the filter.

The lower hole is the oil pressure regulator, and yes, you will have no chance getting the adjustable valve to fit since the starter motor is in the way. I don't see why you need this anyway. If you want a little more oil pressure, add a washer or two behind the spring.

Whether it is an advantage or not, im not sure yet (other than the obvious) but the oil pressure regulator is now fed from number three main bearing oil gallery, not from the unfiltered feed oil from the pump. Now I know there are a couple of miglias running MPi blocks at least.

There are a couple of extra threaded holes on the front end of the block where the front plate mounts, shouldn't be a problem, but at least you are now aware of it. The other thing to remember is that there is no standard alternator mounting, but there are a couple of blank bosses cast into the block, which I drilled and tapped, then made a bracket to fit an alternator in the normal position.

The only real disadvantage is the different oil filer threads. You need to use oil filters form the Rover K series, but at least you can still get hold of OEM MG Rover filters for those fairly easily. I won't use anything ese, and stockpiled up on a few.

You will have to run Megajolt at least since there is no consideration for a distributor

everything else is much of a muchness.

There's also no hole for a mechanical fuel pump. There is a small hole for a cam sensor though, mine has been drilled and tapped and fitted with a little alu bung.

I'll be fitting an oil temp sensor like this one to the port on the front:

http://www.merlinmotorsport.co.uk/p1373/TE...oduct_info.html

I thought the standard relief cap was bit thin for drilling and tapping.

perfec. I'll do that then. Another justification for my lathe

Thanks Guy's, I think i will pass on the block for now. Aaron

Racecar spelled backwards is Racecar

Where is the block and how much is it? I'm looking for a spare and would happily swap it for a standard A+ block

Seattle Wa USA

Racecar spelled backwards is Racecar

ah.... Getting one from Mr Sprocket now, so all is well.