Uprating a 1.7 X/Flow engine from 135 to 150 bhp

[Temple Cloud]

I'm considering looking at uprating my 1.7 X/Flow from 135 to 150bhp but as I'm a noob with these engines have a few questions:

a) Is there a point to this ?

b) Who is the man/company that is the go to person/company to do this in the UK (pref south) as I wouldn't trust myself ?

c) I've been told that with a live axle like mine it's best not to go above 150bhp. Is that true or could I take the engine a bit further yet leave it tractable on the road ?

Thanks for any advice

 

[SM25T]

You could ask Boss Racing in Longfield, Kent ... Dave has been building engines for many years. Phone 01474 702892

[Hampshire West AR]

Would have thought it's expensive. I believe Dave Gemzoe developed a very powerful xflow, worth talking to him.

[Wrightpayne]

Tazio will be along in a minute - his engine was built by Sherwood Engines.

 

I think if I had a crossflow I'd look into installing an English Escort axle. Its heavier and needs some work on the ally tunnel but way stronger. I understand Arch can fit the bracketry to the axle case. Set of front 'Ford' hubs and a significant increase in wheel choice.

[simon_h]

Are you just after more power or want to stay with the xflow? Xflow tuning is expensive. You could almost drop a 2.0l zetec in and get that power easily and for less. Can either keep the xflow for the next owner or sell and recover some costs

[blueyedbiker]

Steve Curson at Vulcan near Brands Hatch knows his way around a X Flow, having worked his magic mine's up at 168hp and drives well.

[Tazio]

Read Graham Sykes definitive article  (search on here) on the Ital axle as it is a weak point, I've gone for a  quaife atb to take some of the strain, not a cheap solution anymore though. also had the driveshaft bearings properly shimmed. If you can find a ford axle it's a much better starting point

As far as the engine is concerned, I can confirm that done properly, a crossflow can be very expensive, when you add new ancillaries, in and dry sump etc.  it's quite easy to spend £10k on one, and a much cheaper route would be a Zetec, but if you are committed to the crossflow, have a look at Harris Performance Engines - Modified Ford Engines since the 1930's (hpemotorsport.co.uk)

[Drumster]

Andy Couchman of this parish has a very nice 150bhp engine running on TBs on his 1986 x/flow which presumably is a live axle. Hopefully he'll be along with more details........

 

[7 wonders of the world]

You ca have the English axle re tubed as it is slightly narrower, the extra weight can be dealt with by using alloy or magnesium nose form Steve @ Tracport and rear discs too, uprated half shafts are readily available too as are plate LSD's

Whilst shimming the Ital axle my preserve its life the Quaffe ATB won't since this offers no protection to the shafts or CWP under engine flare up conditons so these components are still subjected to the shock loading which is decremental to their lifespan.

Lots of Crossflow parts now been remade thich walled blocks iron and alloy, decent alloy heads cranks and rods in various configurations.

2.1 all steel full alloy on TB's perhaps..... 

 

[bstark]

Just reading your original question "is there a point to this?"

It depends what you are trying to achieve. Is it better drivability and real life performance on the road, or a noticeable increase in flat-out performance at the top end?

If the former you might want to look at 3D mapped ignition if you haven't already fitted it as a starting point. It transforms the torque and drivability off a Supersprint spec xflow, 

[Temple Cloud]

Thanks for all your replies. Lots to take in and consider. And there was me naively thinking all I would have to do is swap the camshaft for something sexier and job done. LOL

Here's some points though:

1 As far as the live axle is concerned I've been told they should be fine up to 150bhp. Is that wrong or is a change of axle really necessary ?

2 I hadn't thought about ignition mapping so will certainly investigate. I've been away from these carburettor based cars for probably 40 or more years so need to brush up my knowledge

3 I didn't realise xflow were so expensive to work on so rather than swap the engine for a Zetec which is obviously an option, I'd probably do nothing at all for this summer as the car is great as is and then upgrade the whole shooting match for next year. If I'm still alive that is....

4 I'll deffo speak to the guys suggested though I'd rather they be a little closer to me in Somerset

Thanks again

[OldAndrewE]

There are things you can do without breaking the bank completly. 

Make sure you have a decent ignition system.  Don't know what Caterham fitted but I have got Lumenition. 

Yes, see if there is a better camshaft available (don't know what Caterham fitted). 

Is it suitable for unleaded, don't know what Caterham did (mine is not a Caterham engine) if not you may want to consider getting the exhaust valve seats converted.

Get it set up properly on a rolling road

Even that lot will not be that cheap

Finally regarding the axle I suppose that depends how you intend to drive it.  Round the track hopping curbs it may not survive but normal fast road driving may be OK

I have a Ford axle but I understand it was the Ital axle that permitted Caterham to make the long cockpit.  If you have one of those I do not know if a Ford axle is possible

[Golf Juliet Tango]

Regarding the Ital axle & diff, a lot depends upon how you treat it.  My Crossflow is somewhere a little above 150BHP (although it isn't at the moment ) and I have had no issues for about 15 years with the diff & axle.

[Temple Cloud]

That's reassuring...thx

[dikko]

I was told many years ago that Ital axle was good for 155 and ford 165...

There are some programmable distributors on the market that might make a difference, you can dial them in while you're driving them from your phone... gosh...pref rolling road...

A mate of mine living near Brixham took me to a good man who knows the business with the above gizmo's plus rolling road dyno and is an engine builder (Twin Cams etc) and race prep. Any good? I'll get his details if so.

 

[rkeywood]

Maybe the place to start is what is the engine now. If its a Caterham supplied Supersprint then the 135Hp was probably considerably overstated when new and maybe in the 110 to 120 area. Mine  was 115Hp when new and needed a decent rebuild and some head work to get close to 130. Has the engine been rebuilt or breathed on already? Also was it built on a thick wall block? As said simple things like a luminition and a Bosch disi and a decent set up by someone who knows DCOEs will help a lot. Getting 150Hp+ will be expensive and probably only worth it if its going to get some serious track use. Aiming for 140Hp with a bit more low down power will be considerably cheaper and at should retain quite a bit of what you've got eg crank, cam (should already be a 234) and carbs. The best X-Flow I've tried from all round use was a Roger King 1800 140Hp. Plenty of guts, great response and just as quick on the track as the 155Hp 1700 I had at the time.

I also think the fragility of Ital axles is overstated. If well built then they take a fair bit of abuse, mine's lasted 30+ years including 10 years racing.

[Temple Cloud]

Thanks for the new responses. You've all been really helpful and given me lots of food for thought.

I've contacted a local engine expert at Interpro near Bristol. And when the guy gets back to me I'll book her in for a once over to see what his thoughts are. She does appear to have a distributor so by the sounds of it I'll probably go the route of converting the ignition system if nothing else.

Watch this space

[Roger King]

In essence, a 244 camshaft, forged pistons, better advance curve (or even better, 3D mapped ignition) and competition valves (which are lighter and flow better) with bronze guides or guide inserts will do the job. But there are lots of other things needed to ensure reliability - tufftrided crank, better big end bolts, steel rocker gear, carb re-choking and jetting, etc, etc. You would not believe the difference compared to a standard Supersprint.

[Drumster]

I had a Roger King rebuild, as above, in mine way back in November 2000. It was his 140bhp spec which IIRC retained the 234 camshaft.

ISTR that RK also reckoned Caterham's 135bhp was rather optimistic and that was proven as the 140bhp engine was a far better engine in all regards and the extra 20 horses made a huge difference. Roger is spot on when he says 'you would not believe the difference...' 

[Temple Cloud]

Thanks for that RK and Drumster. I have the car booked in to Interpro in April and they have a rolling road and Dave Griffiths, who is an expert with these engines, will give me the low down but I'll certainly pass on the recommendations, though they sound a bit too pricey and it may be better for me just to enjoy the car as is after a proper tune, keep it for the summer and then upgrade the car altogether by buying another next year. I'll see what happens next month

[Temple Cloud]

Just got my car booked in to an xflow expert in north Bristol for April and in his opinion getting my car to 140-145bhp would be significantly easier and cheaper than trying for 150 as the extra 5bhp has ramification which mean a much higher cost.

He estimates my car is currently probably closer to 120bhp than 135....

Anyway, I'll see on the 25th April what his rolling road analysis and compression tests come up with. Exciting

[eric]

Someone have an idea of the miles / gallon of a 150 HP Engine

I had a sprint engine 1600  112 HP A2 cam  and now a 120 HP rover 1600 K and is just like night and day ....

[Gridgway]

I'm in the middle of a x-flow upgrade.  I'm using CMK engineering in High Wycombe.  Ant there is ace with historic engines and has so far built me a mega pinto for FF2000 and a mega twincam for my Lotus Elan GTS.

He's starting with my 1600 caterham crossflow.  Aim is about 150bhp without getting to excessive cost.  We'll see how we get on, but he's an engine builder I trust!

I'll report back.

[Temple Cloud]

Please do report back. And take some pix of the process. It'll be interesting to see how you get on. BOL

[p.mole1]

Just from previous experience of building engines, do not under estimate the cost! I do not have any crossflow experience but I would think you would need forged pistons, bigger, valves, stronger con rods. Also at that power level the engine may require frequent rebuilds. I used have A series minis and once you upped the power the valve train wouldn't last longer than a few thousand miles before the valve guides would wear with the subsequent loss in compression.  I think a Zetec conversion would be better and probably around the same cost and easily produce 150 bhp reliably for thousands of miles. I think you can get a conversion kit to fit one to Caterham?  

If you get hold of a Burtons catalogue  there is quite a bit of engine information in it