BRM engine help please!!

[trickle]

Can anybody help me with some history on a BRM twin cam out of a Lotus cortina?

[chunterer]

trickle,

I've moved the thread into the main History section as you wish to find out info on the car/engine as opposed to actual chassis numbers at present. You might get more help in here for now!

[GORDON STREETER]

I don't think that they were anything special although some early "Twinks" were supposed to be "tuned" by BRM (Jim Clark's come to mind).
I have seen these cam covers in Elans/26 rs/47s and Cortinas over the years so they probably mean nothing.
You can still buy them from Tony Thompson
I note its got a later crankshaft and could be a BD series one.
I'm aware its mechanical slide injection so it could have been in a single seater at one time ?.

[James Murray]

Interestingly its on mechanical fuel injection, probably Lucas. Pretty rare for a twincam and more common on BDA'S. Most of the injected twincams were used in FB in the USA and the UK based ones were put in saloon cars run by works teams or large privateer teams. What is the history of the Lotus Cortina you took it out of?

[GORDON STREETER]

In 1966 Team Lotus registered new cars for the new series of the British Saloon Car Championship, which ran up to Group 5, as regulations had been changed. Fuel-injection and dry sumping were allowed, and with Lucas injection and tuning by BRM, the engines could put out 180 bhp. As it looks like its been kicking about for a while it "could" be original.

[jonners]

did that really come out of a cortina?? surprised the metering head (if that's what it is) fits under the bonnet - although the cross member on the Group 5 cars was very far from standard.

the tale i heard about BRM twin cams was that they were special as BRM machined the inlet ports rather than porting them by hand - supposedly this made the engines special as each port was identical.

They lost a lot of heads during this process though as there was a lot of variations in the head castings..

The BRM phase 4 and 5 cams used to be all the rage but not sure anyone bothers now. We use a Cosworth profile on the inlet and a BD4 on the exhaust - or is it the other way round??

As Gordon says the cam covers are easier to get now than they were then.

There must be some other identifying feature for a 'proper' BRM engine though??

[Alan Brown]

To commemorate 25 000 Lotus twin cams having been built by 1970 Lotus presented Walter Hayes of Ford with the 25 000th engine. Accordingly, MN (15-10-70) did an article on the engine. Relevant quotes from it include: "Owing to production difficulties Colin Chapman asked BRM if they would continue development on the racing version of the twin-cam for 1965, so Tony Rudd's team set to ... Bourne's dry-sumped products produced some 155-160 bhp and equipped with fuel-injection (as they were in the works cars) they found as much as 185 bhp." Another quote refers to the Elan-BRM marketed by Mike Spence: "Through BRM's involvement with the preparation with the racing twin-cam came a subsequent arrangement with Mike Spence at Maidenhead to market special Elans with BRM modified motors. The power units were sent to Bourne and completely dismantled and then rebuilt with different inlent valves, Cosworth CPL2 camshafts and ten thou and 20 thou respectively came off the head and block. The object was to increase the power of the LF/105 motor by about 20 per cent without any loss in flexibility or smoothness."

An advert by BRM referred to Twin Cam tuning from £485 - Stage 1 135 bhp, Stage 2 155 bhp, Stage 3 175 bhp and Stage 4 180 bhp plus.

[rbs]

I remember a Cortina Rally car with a BRM engine, it could have been driven by John Bloxham, I will have to have a look at some old MN's to confirm it though

[jwoch]

The engine shown is a late mark two with the 701M (Escort) block. It could not therefore have been in a "works" era Mk 1 Cortina.
Some meeting minutes I have from the 60's indicate that Boreham tried BRM engines in the works Cortinas but they were unreliable. BRM were later confined to building Group 1 engines (e.g. for the Monte) which they simply blue printed. Tuned engines (Group2) were built by Boreham engineers.

[p261brm]

Originally Posted by Alan Brown

The power units were sent to Bourne and completely dismantled and then rebuilt with different inlent valves, Cosworth CPL2 camshafts and ten thou and 20 thou respectively came off the head and block. The object was to increase the power of the LF/105 motor by about 20 per cent without any loss in flexibility or smoothness."
.

A complete and as historically correct answer as you will get, but never knew of one with Lucas injection leastways not in a cortina, the FVA made them almost obsolete but some did appear in F2 along with BRM's own F2 engine. Now Alan grey matter stirring I will have check with man himself; just possible? Nomad Mk1 had one before the 1-5 BRM V8 was fitted.

[Gungebucket]

Originally Posted by jwoch

The engine shown is a late mark two with the 701M (Escort) block. It could not therefore have been in a "works" era Mk 1 Cortina.
Some meeting minutes I have from the 60's indicate that Boreham tried BRM engines in the works Cortinas but they were unreliable. BRM were later confined to building Group 1 engines (e.g. for the Monte) which they simply blue printed. Tuned engines (Group2) were built by Boreham engineers.

Not sure about the 701M block, how did you deduce that? The 701 block was taller than the normal twin-cam block and there would have had to be a spacer-plate between the front cover and the head... I don't see one.
Boreham did indeed have reliability issues with BRM engines and yes, all the rally engines were built in house. It looks as if the crank is a 12 bolt version, these were definately not available in the Cortina days and I have never seen a 12 bolt nominal 73mm stroke (standard twink stroke) crank. It could be a 77mm stroke crank. It could be an 1800cc engine, 77mm stroke and 85mm bore, in which case the block would have to be a "big L block" Does the block have a dumpy fat L cast into it as opposed to the skinny "L" on a standard block?
The injection equipment is definately Lucas. There is only one thing to be done...... it is going to have to be stripped and rebuilt! Another indication could be the cam at the back of the metering unit.... does it have a number stamped on it? Usually three digits from memory. Bring it down here and we will have a proper look at it!!

Just one other point.... when I was building Formula B engines they were 1600cc and had to run on carbs... not injection. That was in the early 1970's and things may have changed later. The formula B twin-cams were awesome ... ran to 10,000 rev/min and the pass mark off the dyno was 200 bhp (yes it really was ... 200 bhp from a 1600 twink on carburettors).

Hey Ho ... memories!

[fridgeman]

just think as a amateur by comparison the info above is not quite right,no offence meant but the 701 L block was the escort 72mm stroke and not to be confused with the later 711m x/flow item used to build the long stroke 77mm stroke twin cams with the spacer block.i also had a 701 bottom end with a old cosworth 12 bolt steel crank and rods.it had a x/flow top end and gear driven cam. holbay short stroke race engine.

i need some help as i am restoring a 1970 broadspeed escort twin cam that had a BRM engine.i have the bare bones of the engine that needs a lot of work but are there any defining numbers or marks to show if the heads the real deal.the blocks a 125e [i think] with some numbers ground off. GAFF steel crank and rods,but i think these were added later.



thanks guys.

[zefarelly]

701M is late 60's twin cam block, engine could be from anything, highly unlikely to be originated from a Cortina.

701m block is 198mm tall, same as 1500 precrossflow
711 x-flow 208mm for 77.6 stroke

not all the 701m blocks are as good as people think, many found their way back onto the cooking line . . . . there's nothing to suggest ( looking at the photo's) thats not one that passed inspection.

head could be from an Europa, rear pulley was used for the dynamo on those ?

[fridgeman]

i think that rear pulley rules a escort fitting out,not much room from the bulkhead at all.so if it did come out of a cortina its had a block change.interesting though how and where it all came together.

so is there identifying marks on a brm head.