Sigma Hurricane Build

[Sigma hurricane]

Currently Starting a new Sigma Hurricane build. The car was bought from Robin Vincent when he sold off one of his flock due to a house move. The car had been bought back from a string of previous owners by Robin with lots of history.
 

I intially had no intention to change the Engine in the Hurricane as also had a T6 body is was going to build up as a bit of a track weapon, however the combination of realising that an IVA was going to be a real PITA and engine troubles on the Hurricane i quickly decided to reduce the number of projects.

The hurricane had thrown a rod whilst out for a drive accompanied by a bit of overheating resulted in the head coming off and seeing that the engine had clearly being put together badly at some point. Different size oversizes on the pistons as well as few other issues. However with it being peak summer and not wanting the car off the road for too long i quickly got the head skimmed with a unleaded conversion, Rod replaced and a good engine flush and back on the road.

Car was still running rough so thoughts turned to carbs and timing which on taking it to my local rolling road discovered HS4's shouldnt have been fitted either to the engine however with his expertise the needles were altered to sort that and the timing was adjusted as it was way out. Engine was transformed however still idled rough which we have put down to a worn camshaft.
This has  made me get to the point of thinking i might as well do a engine swop at some point as it could do with a bottom end rebuiild.

I had 2 sigma engines in the barn one used VCT and one spare sealed never used non VCT formula ford spare engine. 
Plan formed was to use the VCT head on the non VCT engine keeping the dry sump for the non VCT.

Indevidual throttle bodies and some head work as well as a new ECU should put the engine in the 160-170bhp bracket which is not bad for an engine significantly lighter than the stock 1300.

Gear box plans are using a RX8 gear box with an adapter plate

Rear end i have a R160 torsan diff ready to go in a 3.54 ratio (parts from 2 different diffs to make it up) plus a billet rear adapter plate.

I havent decided yet if to use the MGF outer bearing or use the stock uprights with a toyota starlet CV though currently leaning towards a MGF set up if i can work out a stock driveshaft that fits (fiesta one i thought would work was too small a diameter) 

Also considering converting the rear end to disc brakes using MGF calipers and a custom bracket.

Also considering getting the car wraped instead of painted as certain panels have reasonable flex and the current paint job hasnt coped well with that.
 

Will update as and when with progress.

 

[Sigma hurricane]

[Sigma hurricane]

A few photos of the before bits and bob's.

The hybrid subaru-> starlet CV driveshafts

My hurricane

The two engines

The T6 shell. (Apparently was the last one as was the one insde the moulds when the moulds went up for sale never to be seen again)

The billot CNC machined back plate. (I intially made it years ago before i started making a few of the standard cast kits with a friend)

[Nick Jones]

Hi Luke, and welcome. Serious projects indeed 

Met Jerry Vincent (Robins brother I assume) at a Castle Coombe track day  last year. Nice guy, driving, off all things, a Vincent Hurricane! Was too fast for me - was relieved to discover it was MX5 powered!

I imagine you’ve spotted my son’s Sigma Spitfire project? He’s made an MX5 gearbox fit the Sigma, but it wasn’t especially easy! Most seem to use the Ford T9, but they’re not very easy to find now.

Assume you are using the 6 speed RX8 ‘box? I have a 5 speed in stock but it’s really the wrong shape for. Triumph Chassis!

That CNC’d backplate is a thing of beauty. Far too pretty to hide under a car!

[Sigma hurricane]

Hi Nick, 

I haven’t actually, I fully read Chris’s T6 sigma build and issues when I was first considering putting it in the T6 shell. 
I also have spoken a lot with Gareth (gt6 sleeper) who did a sigma with a rx8 box in a spitfire with a bmw rear diff which you might recall?

Yep it’s a 6 speed, will probably need a wide angle prop too, the rx8 box I had anyway so worse case if it clashes too much can consider a T9. 
I had it up against a T9 a while back and the dimensions aren’t off by much and it’s a lot stronger gear box than the T9 and a lot cheaper too! First gear isn’t great but if you ignore first it should work well.

Yep the back plate is lovely. I have a mad idea of doing some billet rear uprights too, a bit like the cast Canley ones but they suffer from being cast. 
That and replace the cast iron lower wishbones with adjustable lower A frame ones.

 

[Nick Jones]

Ah, different Chris. The T6 Sigma was Chris Sherrington. He hasn’t posted on here for a long time unfortunately.

My son’s (older son, also Chris) is this one.

He doesn’t post on here but lurks. Think you may have had some contact via FB?
 

I think Canleys did make a few billet vertical links and wishbones early on and they were lovely, but the economics were horrible so switched to cast.

[Sigma hurricane]

Ahh il have a read through that tonight. Lumps of 7075 aluminium (often called aircraft grade) Are around £100 for enough to do the uprights. 1/4 of which would end up being reclaimed as scrap. Once the 3D cnc file is set up shouldn’t be too silly a price going forward… Another project idea to add to the list.

[Sigma hurricane]

Whilst awaiting for me to clear more room in the barn ready for the transplant, been sorting out some awkward bits. In order to avoid too much bulkhead trimming the rear water outlet has been modified. Still debaiting doing a casting run off a 3d printed model for a nicer slightly slimer better flowing profile, especially with the fact you cant buy the shawspeed ones any more.

On the plus side whilst clearing things out of the barn i came across a perfect original chrome gt6 mk3 front window trim suround!

[Sigma hurricane]

Been working on a few new options for driveshafts for the R160 this evening. I had come up with a custom solution previously using custom driveshafts and a toyota starlett CV which enabled use of the triumph rotoflex upright with no modification. I was also looking into the MGF route as i like the no shim bearing option however hit the wall of lack of rover 100 driveshaft availability. 

I thought ford focus/fusion might be a solution however the shaft diamter at the subaru innner CV end whilst being the right spline count is too small a diameter. 

After lots of fruitless searches and a year of thinking why isnt there a database with all CV joints and centre shafts on, i found a data base with exactly that and much more.

https://size.name/en

Found a few driveshaft centres with the right spline 22 inner 22 outer to match the MGF and subaru CV joints. A nissan Almera drive shaft seems to hit the required specs (thankfully the large plunge of the Subaru innner gives a bit of flexabilty.)

So I have ordered a bare driveshaft centre at the cost of £34 to test/pray my theory works.
If it does it probably means a cost of making Subaru => MGF driveshafts sits at around £250.

 

 

[Escadrille Ecosse]

15 hours ago, Sigma hurricane said:

Been working on a few new options for driveshafts for the R160 this evening. I had come up with a custom solution previously using custom driveshafts and a toyota starlett CV which enabled use of the triumph rotoflex upright with no modification. I was also looking into the MGF route as i like the no shim bearing option however hit the wall of lack of rover 100 driveshaft availability. 

I thought ford focus/fusion might be a solution however the shaft diamter at the subaru innner CV end whilst being the right spline count is too small a diameter. 

After lots of fruitless searches and a year of thinking why isnt there a database with all CV joints and centre shafts on, i found a data base with exactly that and much more.

https://size.name/en

Found a few driveshaft centres with the right spline 22 inner 22 outer to match the MGF and subaru CV joints. A nissan Almera drive shaft seems to hit the required specs (thankfully the large plunge of the Subaru innner gives a bit of flexabilty.)

So I have ordered a bare driveshaft centre at the cost of £34 to test/pray my theory works.
If it does it probably means a cost of making Subaru => MGF driveshafts sits at around £250.

 

 

Goldmine

[Sigma hurricane]

So engine bits ready for the rebuild and paint. Thinking silver alluminium high temp paint for the block. Yet to decide rocker cover paint job and if to fit a custom top plate catterham style to hide the leads.

Crank off for a micro polish and to be balanced with the new lightweight flywheel.

New bearings ect but re using pistons just new rings as the engine hadnt been ran much.

Plan is the omex throttle bodies with their standalone ecu. I did consider going down the route of using the triumph bike throttle bodies and have a set however decided the time it would take to set them up correctly was really worth the savings especialy with overtime on offer at work at the moment.

Now just need to clear out some of my shelves of no longer needed triumph spares to make some more room to work!

 

 

[egret]

That looks lovely and clean, always nice to see engine building progress.

[Sigma hurricane]

Thankfully made easier by the none VCT engine being basically brand new. The VCT block is basically a paperweight now cylinders have started to oval clearly high millage and abuse. Thankfully I just needed the head from that one.

The VCT block will be going for scrap.

[Spit131]

HI Luke  ,

You have probably already done so but it is worth checking the Subaru splines against your diff/LSD splines as we found depending on which Subaru inners you used there was sometimes very little mating spline area inside the LSD .

Your project is very similar to mine except it appears you are very capable of doing it yourself . Mine has just been started on at Race Ltd near Gatwick . I will start a fresh thread on it’s progress . Be interesting to see yours progress .

Matt 

SE London 

[Spit131]

I might have spare brand new MGF outer CV’s I could sell to you if you go that route . They were available at Moss or Rimmers . Not cheap though .

[Spit131]

Of course there were two MGF outer CVs , one ABS one non ABS .

[Spit131]

Different spline count .

[Sigma hurricane]

Hi Matt,

Thankfully i have a shelf full of subaru inners from making up R160 triumph conversion kits over the years, ended up building up a few diffs with the kits too. The matting area shouldnt change to be honest, there is different spline count inner CV's as well as the earlier double splined CV's and the stub bolt on inners too. 

Il be honest i tend to avoid Rimmers for anything as they are a bit on the expensive side. You can get old stock MGF OEM CV's for way less than they are selling theirs.
 

[Spit131]

Sounds like you have it nailed  .

[Sigma hurricane]

So today was a good progress day. After spending the last 2 years trying to find a viable alternative to Nick Jones solution for drive shafts using the now unobtanium rover 100 drive shaft with the R160 diff

The new bare shaft I have found is for a car that is still made so shouldn’t have availability issues. Static loading torque test complete this eve with a Subaru bearing race on one end and the mgf cv joint on the other end with it being loaded up to 250 lb-ft to make sure both side correctly grip on the spline. Visually and feeling the connections it seems like a perfect fit. Only things I haven’t checked is the circlip position on the shaft for the mgf end however worse case a cut off wheel will fix and I also want to set it up on my half chassis  test bed to make sure works fine with full range of movement. 

Once that’s all done and it’s fine il publish the shaft details to avoid people finding the thread and going down a rabbit hole presuming it works.

Fingers crossed it all works fine as it will allow me to shift the numerous R160 triumph conversion kits I have on a shelf.

 

[Sigma hurricane]

Managed a quick test on the scrap chassis on length up the the R160 diff and it looks good. I want to do a full motion range test before I put all the details out to avoid people going on an wild goose chase.

Only issue I have found is the c clip retaining slot for the MGF side is a bit short. The teeth have full length engagement in the CV however don't protrude far enough in to clip in. Simple solution would be to carefully grind a slot on the MGF CV teeth to solve that. Plus with it being rotoflex upright it’s not like there is a huge amount of side loading anyway it just needs to offer more resistance than the inner CV’s full range of movement. 
 

(I did also check using a fiesta CV as almost identical to the mgf one however that doesn’t help.)

 

Down in the rainy south at Gatwick for the week now for work so won’t be able to finish testing now till next week. However did manage to make yesterday and today put a new opening in one of the barns to use as an aditional garage ready for the hurricane transplant. 

 

[Spit131]

Interesting .

[Sigma hurricane]

Whilst away i was also trying to do some guestimates on current weight of the hurricane and also eventual weight post transplant ect.
Looked at car weighing scales however they are silly money.

Considering getting 4 parcel weighing scales that can do 200kg each and use that. It would also help me try and get the weight distribution better.

The sigma engine and gearbox should knock around 25kg's off the front end plus will try and mount as rear as possible. Plus the increased weight at the rear switching to rotoflex and the R160 diff should hopefully be enough but thinking if it at least weighed before i do anything it should give me a good estimate of the final weights.

[JohnD]

Sigma,

Have you considered a weighbridge?    Commercial vehicles must be weighed and these are there to do that.

To find one, ask your local council if they have one, or else look at: Find a weighbridge - GOV.UK

John 

Edited December 3, 2024 by JohnD

[Sigma hurricane]

I

28 minutes ago, JohnD said:

Sigma,

Have you considered a weighbridge?    Commercial vehicles must be weighed and these are there to do that.

To find one, ask your local council if they have one, or else look at: Find a weighbridge - GOV.UK

John 

I did think of that for a initial messurement and used one locally before when towing heavy things behind a tractor however most are only accurate per corner to 20kg's which has potential for issues and once i start taking bits off wont help much. I can do the 4 parcel scales for just over £100 total.

 

Plus the wife will be happy that im not using her kitchen scales or bathroom scales evertime i end up posting some car part off......