Beta Coupe GCRE upgrade

[betabuoy]

With my Coupe now out of storage, I’ve decided that it’s time to sort out the engine and to up its spec.  I’ve admired the work of Guy Croft for years and, in my view, there is no better place for an engine rebuild than his works… GCRE in Lincoln.  

A few weeks ago, I spent an afternoon with Guy himself: We talked for hours about pressure waves, cam overlap, primary/secondary exhaust sections etc and when it was time to go, I left with a copy of his new book which, if you don’t yet have a copy, I thoroughly recommend.  

Later, having removed the engine, I stripped it to basic components and - along with another block and three other heads - I took all the big bits to Guy for him to select the best items.  Guy chose a very original 105 TC head (with 43.5mm inlet valves); my coupe’s original block; the oil pump and sump; and finally, the aux driveshaft, crank and lightened flywheel that he’d modified for me back in 2006.

On my next visit, we discussed the spec for my engine.  My stated requirements were: Occasional daily commuter (that’s North Yorkshire roads – not city centres!); hoofing along country lanes; long-distance fast touring; and of course... the occasional track-day!

Work started in November and Guy has been sending regular updates: The head is nearing completion with ops including enlarged ports, improved gasflow, triple valve springs and race guides; and it will probably carry Guy’s IIIA cams for the best overall lift profile.  The block has been re-bored to 85mm and has had a light re-face; this will be powered by Guy’s own-design forged pistons (CR 10.2:1) and Cunningham ‘rods and for lubrication it’ll have a baffled sump with an added cooling matrix.

More pictures to follow as it comes together.

[HFStuart]

Are you back in the UK full time now then?

There's no finer place for T/C work but Guy's standards are so exacting ( ie his way or not at all  - fair enough with the knowledge he's got) that that must be setting you back a pretty penny.

I'll look forward to the results - I presume you'll be setting it up on the rolling road. What carbs will you run ?

[betabuoy]

Hi Stuart

Yes thanks, and its nice to be back. 

Carbs will be twin 45 DCOEs...that was an early decision for me.  And, as I understand it, the porting of the head has been all based around optimising that feed.  For set up, Guy usually uses and recommends the team from Northampton Motorsport and I see no reason to deviate.

Chris

[betabuoy]

Spent a very enjoyable few hours with Guy on Wednesday.  The head prep is complete and I must say the detail and quality of work is staggering.




The block has been thoroughly cleaned, refaced and bored to 85mm.  Guy has just microhoned the bores with FlexHone at 240 grade ready for GC race pistons and rings.



Having confirmed the deck height, next event is to order the GC JE A8M pistons... and of course do a bit of painting!

Chris

[betabuoy]

Another nice nice day down at GCRE last week and a pleasure to chat and watch Guy at work.  Whilst certainly not the most rapid engine build, this is more down to my project growth rather than Guy's slow progress.  My engine has been the one he agreed to fit in but its all coming along nicely now.

Photos below show the current state of play:

1. IIIA Cams in Boxes
2. Inlet porting, race guides and triple valve springs.

Engine block should be on the stand soon and ready for dressing.  New completion date set for early June... I'll post more pics as it comes together.

Chris

[betabuoy]

As a 21 yr old hooligan, it always annoyed me when the oil pressure dropped when cornering hard in my Beta.  Still an occasional hooligan - but a bit older(!) - I have great expectations for the new GCRE Beta baffled pan design... 

Tig welded sections give a bulkhead across the middle with a trapdoor that opens to allow oil over the pick-up.  This should minimise the aeration and oil starvation issues. 

[HFStuart]

I've got one of them. I can testify I didn't get any oil surge with it fitted - unlike the previous trap door design.

[mangocrazy]

I've got one of them. I can testify I didn't get any oil surge with it fitted - unlike the previous trap door design.

Was the previous design also one of Guy's (and the one that BetaBoyz sell) ? I've just fitted that one to my engine so will be a bit miffed if the new design is substantailly better. Mine will only get road use, though.

[rossocorsa]

I've got one of them. I can testify I didn't get any oil surge with it fitted - unlike the previous trap door design.

Was the previous design also one of Guy's (and the one that BetaBoyz sell) ? I've just fitted that one to my engine so will be a bit miffed if the new design is substantailly better. Mine will only get road use, though.

I think I recall that GC once commented to be that the BB one is a copy of his older design. I recall he did say it was ok as a design but he'd done an improved one since. I have the BB kit fitted to my sump but haven't tested it out yet as the car is still in bits. I did find that it didn't fit very well and needed quite a lot of adjustment.

[HFStuart]

Alan is spot on. Possibly I mucked up the installation but I didn't find it worked that well - although better than the OEM one.

[betabuoy]

The simple picture below hides amounts of blood, sweat and tears shed at GCRE.  The spec to use race gauges meant dealing with a mixture of BSP and Metric threads with the inevitable machining required to get the oil pressure gauge sender, oil temp sender and 20 psi low pressure warning switch ALL onto the Beta oil filter housing.  It took Guy a bit of careful planning; he called it - "putting new things into old things never designed for the purpose...."

All that said, he's done a nice job!

[WestonE]

Prepared to be shocked by the difference in readings and speed of response on these accurate gauges to the originals. I assume they take the place of the stereo and you use a Bluetooth amplifier for music from a phone?

Enjoy

Eric

[betabuoy]

Yes... I’ve discounted the idea of plastic pods some use for these gauges in favour of a suitably placed aluminium panel.  Haven’t completely committed to layout, but that area where the radio was is nicely in the field of view and is certainly favourite.

[betabuoy]

Oil filter housing now fitted.  The build up begins!

[Neil-yaj396]

The 'GC' blanking plate is a nice touch.....

[betabuoy]

The crank is in too.  

Its had the full GC prep: Unplug, remove old end bearing, decarbonise, Jizer and hot wash.  After inspection, all edges are demurred, thread out the oil galleries and slightly modify the oilways.  Guy's SOP - the cranks from 2 litre models MUST NOT be reground; if they're damaged, they're scrap! Instead, he simply prepares them by a light rub/polish with Scotchbrite before further Jizer and hotwash then re-plug of the oilways.  

[betabuoy]

The 'GC' blanking plate is a nice touch.....

Agreed.  And I think Guy has a stock of these so its a tidy solution for anyone considering going down the electric fuel pump route.

[George-S]

Hi guys,

Great work Chris looking forward to some more updates!

One thing I want to ask... I haven't ever heard of oil starvation before at least not on the coupes.
I am about to start my engine rebuild and would love to make a similar modification to my pan to hopefully rectify that issue for the future.
Stuart or Chris, can you talk me through what I need to do?
Any documentation would be awesome also.

I would really appreciate it!
Cheers George

[rossocorsa]

Hi guys,

Great work Chris looking forward to some more updates!

One thing I want to ask... I haven't ever heard of oil starvation before at least not on the coupes.
I am about to start my engine rebuild and would love to make a similar modification to my pan to hopefully rectify that issue for the future.
Stuart or Chris, can you talk me through what I need to do?
Any documentation would be awesome also.

I would really appreciate it!
Cheers George

It depends how fast you drive but the standard sump is rather compromised. This is due to the transverse layout it makes a good internal layout awkward for mass production. Essentially the cure is to cut out the original baffle and fit a more sophisticated option. GC will of course do a perfect job but not everyone can afford his prices, there is the BB kit or if you can find the pattern and are good at metal work you could probably make one yourself

[HFStuart]

  Guy's SPO - the cranks from 2 litre models MUST NOT be reground; if they're damaged, they're scrap!

That's a bit black and white. I think Guy acknowledges that the cranks can sometimes be saved but that it's not always worth it and for his engines he doesn't do it. The difficulty is the surface hardening on the OE crank and the possibility of micro cracking during re-hardening. To rescue mine (after I'd spend several hundred with guy doing all the ops you outline) I had it partially ground, re-hardened, crack tested and then re-ground to 2nd undersize. The depth of hardening is more than is removed in the final grind so you are left with a hard journal surface. The only problem I had was forgetting to take the woodruff key out of the crank  - it ended up with a ceramic like hardness and took ages to remove.

I ran that crank in my 150bhp engine for 4000 miles with no problems. Note I'm not saying that this process will work for anyone else. The crank may well fail crack testing. I thought it was worth a punt and got away with it.