Rover 200 BRM - 1.8 K-Series turbo project

Rover 200 BRM - 1.8 K-Series turbo project

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Stuballs

Original Poster:

218 posts

100 months

Saturday 14th November 2015
quotequote all
Hello!

Thought I would share my project here. I've always had a soft spot for Rovers with my first car being a 1.4 200 Si. The BRM is not to everyone's taste but I love how different it is and always wanted one. I bought this one a few years ago for £600! If you're not familiar with it, it was an (arguably ill-advised) attempt by Rover to revamp the brand in this limited-run hot hatch, which was derived from the 200Vi. It has the same 143PS 1.8 VVC engine but with Torsen LSD and various cosmetic tweaks which are a nod to the BRM racing car of the 60's.

My plan is to make it better but retain road manners and driveability. It's a great car but could do with more power to back up its crazy looks. More power will require uprated brakes and suspension. More power in a K-series will require much better cooling.

The K-series has traditionally been tuned in normally aspirated form with headwork, hot cams, and throttle bodies getting you up near 200bhp. However in recent years there has been a growth in guys playing around with turbocharging the k-series. Some of you may recall Lee Conner's Elise on here powered by a K-Turbo...

So I decided to go TURBO!

This is how the car looked before work started:



Basic spec of engine

- 1.8 k-series block

- Wossner low comp (9:1) 80mm forged pistons

- Maxspeeding steel rods

- Westwood Ductile liners

- Ported VVC head with solid cam conversion

- T28R ball-bearing turbo (from a 200SX S15) with billet comp wheel

- Emerald management


The weaknesses of the k-series are well known and it obviously has a reputation for eating head gaskets. The problem I had initially was that there are lots of unknowns. Rover made a low-boost (5psi) turbocharged 1.8 K-series which was originally for the Mexican market due to emissions regs. But it actually worked so well they used it worldwide in the Rover 75 and MG ZT. It turned out the K-series responded well to forced induction.

When it comes to aftermarket tuning with higher boost, however, So few people have turbo or supercharged the k-series (and even fewer have documented their results in detail) that I was working blind for the most part. It was clear that much more than 200bhp would probably require stronger cylinder liners, pistons and rods to be reliable long term. More than 300bhp would probably be unusable/unnecessary in a front wheel drive road car and I’d be placing other parts under stress that are difficult and/or expensive to upgrade (Crankshaft for example). Revs will be kept at a sensible 7,000rpm. So 300bhp became my upper limit, with a rough target of 250-270bhp. Not ground-breaking but the extra torque from the forced induction combined with relatively lightweight chassis and a turbo choice giving very little lag, should make for a very fun car to drive every day.

My first hurdle was to find suitable forged pistons and steel rods, as without viable upgrades the build was going nowhere. I needed a low compression ratio for forced induction. The stock 1.8T uses 2mm shorter rods to lower the CR to 9.2:1. My upgrade options were few and far between but eventually settled on Wossner pistons custom designed by Jonathan at JDM Dyno (well-known up north for tuning Elises).

Donor engine - I started with a low-mileage turbo engine as it came with all the outside bits I would need - K-Turbo manifold, oil filter housing with the fittings for turbo feed, etc.





Got it up on the engine stand and started stripping it.





All stripped and cleaned (not using this head):



Naturally, a splash of colour:



Back on the engine stand



Essential for a reliable tuned k-series: Uprated liners. A few options but I went for the most robust - Westwood ductile iron liners. Liners on the 1.8 K-Series are very thin as it was not originally designed as a 1.4.



Trial fitting and measuring the stand-proud. Happily have a universal 0.004" above the deck. Bang on!





This project couldn't really get going until I got the pistons. As I said earlier there were a few options. In the end I opted for JDM Dyno designed Wossner pistons. Jon at JDM has the rights to these pistons so you can only order through him. Annoyingly, an order couldn't go through until there were several confirmed orders. I waited over a year for this to happen and in the end just ordered two sets to get it through!





They are basically a dished piston which reduce the compression ratio to about 9:1. Big boost would require less than that (8:1) but these are designed for moderate boost (12psi) to retain good off-boost driveability. That's the idea anyway! They also retain the 18mm pin (floating).

I went for Maxspeeding rods. I believe that they will be more than adequate for my purposes. I was very impressed with the build quality. I've included some side-by-side pics with the standard turbo rod and piston















Next: Putting it together...

Edited by Stuballs on Monday 7th August 09:17

Podie

46,630 posts

274 months

Saturday 14th November 2015
quotequote all
I have a strange soft spot for the BRM....

Good work - interested to see this progress.

Rick448

1,677 posts

223 months

Saturday 14th November 2015
quotequote all
Very interested to see progress on this. Must be costing a fair bit for all that. I hope it gives you what you want.

Stuballs

Original Poster:

218 posts

100 months

Saturday 14th November 2015
quotequote all
Had the whole bottom end balanced by Vibration Free. Intetesting results:

Crankshaft was way outside of factory tolerance (apparently supposed to be within 40gmm). It was109gmm at the pulley end and 368gmm at the flywheel end! Now down to  30gmm at both ends. No explanation for why it was so out. Apparently on later engines from Rover the tolerances went out the window.

Flywheel
Before: 324gmm
After: 6.6gmm

Clutch cover (Borg and Beck)
Before: 733gmm (!!!)
After: 28gmm

Pulley
Before: 342gmm
After: 17.2gmm

Pistons were within 0.8g and rods were within 0.7g. Now matched.

Now to check clearances before the final rebuild. Time to get busy with the plastigauge...









Balanced crank installed with shiny new main bearings.



A few bits ready to go in.



Measuring ring gaps



Rings on pistons and pistons on rods, with shiny new big end bearings.



Westwood ductile iron liners ready to seat with a bead of Hylomar blue.



Liners going in



Liners clamped in with my DIY liner clamps. Probably overkill but I thought I was going to have to turn the crank to get the big ends bolted up, and you're not supposed to turn the crank without the head torqued down!







At this point I got a bit paranoid about piston ring gaps so went back to double check. Wossner provide conflicting information on their ring gaps. When I checked the first time the info I found suggested 0.2mm - 0.35mm. However I then found a guide on their website suggesting around twice that. I went with the latter to be safe. So most of the rings had to come back off the pistons to be gapped!

Filing with a metal file was getting me nowhere. Rings are made of incredibly hard material! 20 minutes on one ring didn't get me anywhere. So I rigged up a tiny dremel grinding wheel in my drill and had it spinning very slowly. Worked a treat!



A time consuming process and you have to be so careful not the scratch the (very expensive) liners putting the rings in for measuring.



So now I can finally getting the pistons and rods in! I expected to have to turn the crank 180 degrees to get 2 and 3 big end caps bolted up, but I had access to all 4 with the crank at TDC, so didn't bother.

First time using a piston ring clamp. It's virtually impossible to keep the rings still whilst clamping up. Hopefully they stayed more or less where they should be!



All in!












Edited by Stuballs on Wednesday 4th October 14:03

italian job

246 posts

230 months

Saturday 14th November 2015
quotequote all
Great thread,please keep the updates coming

AdamIndy

1,661 posts

103 months

Saturday 14th November 2015
quotequote all
I look forward to seeing the progress with this. I am in the minority and actually like the K series, it's an under rated engine. I assume you will be going multi layer steel HG and ARP head stud conversion? I feel the length and material of the original head bolts was the downfall.

A tuner I used to know swore blind that using a multi later steel gasket and ARP stud conversion would cure the HG failure for good.

Mr Teddy Bear

186 posts

190 months

Saturday 14th November 2015
quotequote all
How did you tighten the nuts on your home made liner clamp Stu ?


Also those balance tolerance figures that you quote from Vibration Free, is that static or a dynamic form of balancing ?

Edited by Mr Teddy Bear on Saturday 14th November 23:49


Edited by Mr Teddy Bear on Saturday 14th November 23:49


Edited by Mr Teddy Bear on Saturday 14th November 23:50

Stuballs

Original Poster:

218 posts

100 months

Sunday 15th November 2015
quotequote all
AdamIndy said:
A tuner I used to know swore blind that using a multi later steel gasket and ARP stud conversion would cure the HG failure for good.
I'll be using the so called "n-series" gasket developed by SAIC for the kavachi engine. It's a 6 layer mls gasket. It's to be used in conjunction with higher tensile bolts (head 10.9 vs the old 9.8) and strengthened lower oil rail. The strengthened oil rail (which is the bottom of the "sandwich" the stretch head bolts bolt into, was developed to limit torsional flex of the engine and is one piece in the head gasket failure puzzle).

I prefer not to use studs and nuts because the aluminum block and head are one big sandwich with the cylinder liners pressing the gasket against the head. Every time it heats up and expands the oe stretch bolts expand a bit too. Using studs with much less stretch will increase the load on the fire rings and in the liner seats.

Also, the load on the main bearings is determined by that clamping force. It's so important in fact you can't turn the crank without the head on and properly torqued down. I don't like the idea of messing with that design.

It's a lot of theory though and I accept a few others have done it without issue. I just didn't want to stray too far from the original design and instead focus on just improving how it works and fixing other things. For example, using a pressure relief thermostat at the engine exit to avoid thermal shock the oe setup suffers from (where the thermostat is at the entrance to the engine right by cylinder 1)

Mr Teddy Bear said:
How did you tighten the nuts on your home made liner clamp Stu ?


Also those balance tolerance figures that you quote from Vibration Free, is that static or a dynamic form of balancing ?
Tightened in accordance with the head bolt tightening procedure, but more gradually.

It was all dynamically balanced.



Shadow R1

3,798 posts

175 months

Sunday 15th November 2015
quotequote all
Great thread. smile
Please keep the updates coming.

rossub

4,400 posts

189 months

Sunday 15th November 2015
quotequote all
I do like the look of these. The 3 doors and the wheels just look so right.

anonymous-user

53 months

Sunday 15th November 2015
quotequote all
What a great project. Hardly the key concern, what with all this turbocharging and updating going on, and I'm a chrome grille sort of person, but this looks like one case where a body colour grille might really work to emphasise the lower "BRM" grille?



Will follow with interest.

Motorrad

6,811 posts

186 months

Sunday 15th November 2015
quotequote all
Really enjoyed reading that. Will be great to see the outcome. I have a soft spot for the BRM despite the tart's handbag quality of some of its cosmetics!

J4CKO

41,282 posts

199 months

Sunday 15th November 2015
quotequote all
Had one of these, loved it but it had the HG failure, fixed it but the liners had sunk and it was still pressurising, sold it at that point.

Interesting project, how will you cope with 300 bhp in conjunction with BRM seats, I found them not very supportive and very slippy.

Stuballs

Original Poster:

218 posts

100 months

Sunday 15th November 2015
quotequote all
Thanks guys

I want to keep the stock look as much as I can. That said, the previous owner did de-chrome the grill and sprayed it the same "sparkle silver" as the rest of the trim. I quite like that.

Seats could be more supportive but this will be a road car so I'm not too worried. The interior is one of the BRM's style points (love it or hate it) so it would be a shame to lose that for some aftermarket bucket seats. But if this was a track car I'd have no choice.

RS Grant

1,416 posts

232 months

Sunday 15th November 2015
quotequote all
Podie said:
I have a strange soft spot for the BRM.
Likewise!!

Look forward to seeing the updates and progress in the build. smile


Cheers,
Grant

James_G

345 posts

183 months

Sunday 15th November 2015
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Very interesting and I will be watching this with interest. Some real engineering integrity with the approach too.

Gilhooligan

2,211 posts

143 months

Sunday 15th November 2015
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The odd time I saw one of these, I just presumed they had been 'barry'd' by an owner who likes orange ha.

Fair play OP.

Stuballs

Original Poster:

218 posts

100 months

Sunday 15th November 2015
quotequote all
This was behind their thinking:


Beedub

1,954 posts

225 months

Sunday 15th November 2015
quotequote all
Well done!!! actually really like these cars!

Paul S4

1,181 posts

209 months

Sunday 15th November 2015
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Re the F1 car....is that the legendary BRM V16 F1 engine in the background ? Was at Donnington once for an Historic Race meeting and heard one of these go past...incredible noise !