2.5ST MFI motor build

Nick Moss · Post by **Nick Moss** » Sun May 31, 2009 12:53 pm

This is the motor that will going into my ST replica - the pink one,

The build is being completed by Nick Fulljames of Redtek, he has already built the motor that we fitted to Ferry Man's Turkis Blue hotrod. That was a 2.9 motor built for torque and drivability, this is a much more radical motor, built to thrive on revs and will be powering a lighter shell.

We started with a set of perfect un-numbered 7R cases, that Nick checked for line bore, which was perfect.

Next he machined the barrel decks to ensure a good straight base for the cylinders and timecerted the head bolt threads to make sure we don't pull the ARP bolts out..

The insides were boat tailed, the main bearings were shuffle pinned and the oil pump bypass mod carried out

Nick Moss · Post by **Nick Moss** » Sun May 31, 2009 5:51 pm

The cylinder heads are based on 2.2S heads, machined for twin spark plugs, ported and flowed and fitted with new valves and guides. The barrels are Mahle with custom high compression pistons

Highfield · Post by **Highfield** » Sun May 31, 2009 7:12 pm

Nick

Bumped in to Francis Tuthill today and he mentioned a set of 2.5 P & C - are those going in to this engine if long stroke?

Ian

Nick Moss · Post by **Nick Moss** » Sun May 31, 2009 9:04 pm

The B&Ps that Francis saw were ones originally destined for this motor, but not used. They are 89mm Nickies with JE pistons.

johnM · Post by **johnM** » Sun May 31, 2009 9:17 pm

Looking great nick, it shoud be fantastic. Would love to build a similar spec motor. What fuel system are you going to use? carbs or MFI.

Kind Regards

oliveR · Post by **oliveR** » Mon Jun 01, 2009 7:34 pm

Very nice Nick!
MFI/high butterflies ???

Cam Arnott · Post by **Cam Arnott** » Wed Jun 03, 2009 11:17 am

Nick

What are your port and cam specs for this engine?

What sort of revs are you looking taking this to being long stroke?

Thanks

Cam

Highfield · Post by **Highfield** » Wed Jun 03, 2009 4:56 pm

Nick / Cam

I assumed an 89mm bore would be a short stroke with a 66mm crank !

Short or Long, will be watching with interest.

Nick - are the P&C on Ebay the ones from Francis

Would go nicely in my 2.4T for a long stroke 2.5 - trouble is I would need loads of other parts as well and that would be $$$

Ian

Nick Moss · Post by **Nick Moss** » Wed Jun 03, 2009 6:30 pm

Take one set of 2.2S magnesium stacks and throttle bodies, bore to suit the new ports sizes and fit with new bushes and butterflies

Nick Moss · Post by **Nick Moss** » Wed Jun 03, 2009 6:32 pm

The crankshaft is a 66mm stroke version from 2.2S, the rods are custom Pauter rods. This will be a "short stroke" 2.5

What sort of revs are you looking taking this to being long stroke?

Looking for 8000 rpm

are the P&C on Ebay the ones from Francis

The P&Cs are mine, not Tuthills, he just saw them at Husborne Crawley. They will need some work to bring the CR down to a sensible level with a 70.4 mm crank. They are 10.5:1 with a 66 mm crank

dizzycap · Post by **dizzycap** » Thu Jun 04, 2009 2:38 pm

very cool project!

i will be following this build closely as i am hoping to build (or have me built) a very similar engine.

Can you tell us more about the specs? Oil pump? Piston squirters? Cams? Distributor? etc.

Cheers!

Nick Moss · Post by **Nick Moss** » Sun Jul 19, 2009 1:29 pm

Nick Moss · Post by **Nick Moss** » Sun Jul 19, 2009 1:32 pm

Nick Moss · Post by **Nick Moss** » Sun Jul 19, 2009 1:44 pm

The head bolts are ARP, the oil pump is an SC type. The valve springs and retainers are custom JB Racing parts. The heads have been ported to 38mm and 35mm, twin sparked and the CR set at 10.4:1

Nick Moss · Post by **Nick Moss** » Sun Jul 19, 2009 2:02 pm

The cam carriers have been refaced to ensure a good seal with the covers

The rockers have been shot peened