64 replies to this topic

[stoneface]

Thanks for the photos, interesting. Some of these conversions do tend look a bit messy with gearbox and block mods so nothing unusual.

 

Shame about the flywheel hopefully it was just left out.

 

Please put some photos of the crank extension up if you strip it down that far.

[Spherix]

I've unfortunately heard that the flywheel/clutch assembly is nowhere to be found; the guy I bought it from had the engine sitting for 30 years without ever tinkering with it, he assumed the shop who built it left it out. Glad that crank bolt is at least with it, but now I'll be needing a whole bunch of parts.

 

Seeing as I don't know the torque figures of this engine, and only a 'told' bhp figure of 120-125hp, I cross referenced some pinto specs. Flywheels seems to often range in the 5kg (fast road/rally) to ~9kg stock. Bhp/Torque for a standard engine 95hp 163nm. A guesstimate at 125hp (no data on cam and headwork atm) would mean I'd have to deal with 200nm torque on the clutch? 

 

I'm not familiar with tuning the clutch/flywheel/gearbox side of minis, it's usually been the bolt on mods and stage 3/4 heads for me. Seeing as flywheels tend to go for high numbers (even stock) on the usual part supplier stores, I found tons of listings on ebay. Stock units including clutch for ~20 pounds, vs new 'performance' setups for 200-250gbp. Does anyone have any advice on what type (verto/non verto) and weight flywheel and what grade of clutch? 

 

The seller mentioned the main issue was getting traction on the wheels, hence the LSD was fitted, but I'd rather not burn through standard clutches either. I may not be a speed freak, but I do like acceleration in a fast road car. Reading on up the LSD also tells me this may not be the ideal choice for me, and that perhaps a Quaife type might be better suited for my driving needs.

 

The only clutch part that came with the car is this pressure plate by the way, stamped 22A598 and stock by the looks of it.

 

 

I'll be splitting the transfer case during the weekend to find out more about the crank, but I reckon I'll need to take it all apart to get it balanced now that I have to get a new flywheel/clutch assembly anyway.

[stoneface]

My x-flow is running 132bhp, 112lbft (150Nm) with a pre-verto clutch system.

I had a grey plate fitted but just changing to an orange plate.

My flywheel is only slightly lightened to 5.625kg with a standard back plate.

I personally wouldn't have an LSD on a road car but it is personal choice.

Edited by stoneface, 28 January 2021 - 11:21 AM.

[KTS]

may be worth considering the RTS modified verto type..

 

https://www.theminif...ts#entry3650677

[Spherix]

I have read up on those the last few days, but I'd prefer to go for something that I could buy off the shelve in case something went wrong. I don't mind the 'hybridness' of the engine itself, as long as serviceable items remain standard/off the shelve The car I'm building is one that I want to drive, not just speed around the racetrack, so reliability, serviceability etc. is all taken in to consideration. 

 

I don't know the intention the builder had with the car, but by placing such a harsh LSD and presumed uprated clutch, they were struggling with getting power on the road; after contacting the selling party about the missing flywheel/uprated clutch, he contacted the builder again and they mentioned most of the struggle came from the tires not gripping vs the clutch not catching, and that a stock clutch could do just fine. Reading along the turbominis forum about how to handle torque I don't think a 100% stock/standard clutch is going to cope nicely though.

 

@Stoneface, why the 'downgrade' to an orange spring? Was it too harsh on your foot when driving often?

[GraemeC]

You only really want a spring capable of handling the torque - using one too strong will both give a heavier pedal than necessary and also potentially wear the crank thrusts quicker.

On a properly set up flywheel assembly, the springs can handle much more torque than people think.

 

Likewise, on a road car I wouldn't contemplate an LSD - a Quaife ATB would be the most.

[DomCr250]

I have read up on those the last few days, but I'd prefer to go for something that I could buy off the shelve in case something went wrong. I don't mind the 'hybridness' of the engine itself, as long as serviceable items remain standard/off the shelve The car I'm building is one that I want to drive, not just speed around the racetrack, so reliability, serviceability etc. is all taken in to consideration. 

 

I don't know the intention the builder had with the car, but by placing such a harsh LSD and presumed uprated clutch, they were struggling with getting power on the road; after contacting the selling party about the missing flywheel/uprated clutch, he contacted the builder again and they mentioned most of the struggle came from the tires not gripping vs the clutch not catching, and that a stock clutch could do just fine. Reading along the turbominis forum about how to handle torque I don't think a 100% stock/standard clutch is going to cope nicely though.

 

@Stoneface, why the 'downgrade' to an orange spring? Was it too harsh on your foot when driving often?

 

That's always been the issue with modified mini's.  Even when Vizzard built the Cars and Cars Conversion 1430 (late 70's) with a similar power to yours it still struggled to put the power down on 165's.  On mine (about 125hp from a Swift GTI engine and box with mods) you learn to live with it on the road and ease the power in gradually.  People think the limitation is the driveshafts, but with road tyres it's often just the lack of ability to put the power down.

 

I use Yoko's, got sets of A008's and the A032R's - I find on the road the A008's tend to spin up less but on the track the A032R's are very marginally better.

 

You might get away with a Metro Turbo clutch plate, I found it tool some serious punishment (when I ran A series lumps) and still came back for more ... super cheap too. 

[stoneface]

@Stoneface, why the 'downgrade' to an orange spring? Was it too harsh on your foot when driving often?

 

The short answer is the clutch was heavy and I wore the thrust washers out with the grey. The long answer…..

 

I built my engine along time ago and back then the bhp and torque was considered a lot for a standard mini gearbox and clutch.

 

I was running SC drops and SCCR gears with a 3.2 diff and grey diaphragm.

 

As a road car it was horrible. The gearing was wrong and you needed to slip the clutch a lot. The SC drops where horrendously noisy and the acceleration was not as good as I wanted. So, I didn’t drive it as much as I would like. Don’t get me wrong, it’s quick and fun, but could have been much more enjoyable.

 

I've run my engine for some years, but was always aware the grey diaphragm was putting a lot of pressure on the x-flow trust washers. Bear in mind that the x-flow only has one washer (1/2 a circle) each side of the center bearing and not 2 per side like a mini or pinto. Most these conversions were on race cars which are stripped regularly.

 

The last oil change I found silver particles in the oil. The thrust washers where my first thought so the engine came out, and yes they were worn out.

 

So, after running the grey and never having an issue with the clutch slipping, but always conscious of the thrust washer wear I’ve decided to change to orange. I’ve not tried it yet as I’m currently rebuilding my engine. But I do have both the orange and grey diaphragms balanced with the current setup, so if orange in no good I can change back.

 

Others I’ve spoken to say the orange should be fine. The real issue is getting the power down without spinning the wheels.

 

Also, while I had the engine out, I fitted steel main caps and had the center one machined to take a second thrust washer. In fact, I now have pinto thrust washers fitted. So even if I have to go back to the grey it should be less of an issue now.

 

I’ve also changed the gearbox to A+ helical gears, helical drops, probably keeping the 3.2 diff. Should be a much better road setup. And quiet. Will be back on the road shortly.

 

Nowadays the turbo boys are putting much more through these gearboxes and we know a lot more about what they will take. Also, the power delivery of a normally aspirated verses a turbo engine is different. But you can blow anything up if you try hard enough.

 

I’ve not really looked at the RTS in depth, but apart from the re-balancing and parts required, I believe I would need to change my starter motor, or fit the ring gear to match my inertia starter motor. My starter motor is high torque but I’ve modified it to give me more clearance for a front mounted radiator. So not a straight swap and not cheap.

[Spherix]

Very helpful feedback! Wanting to drive the car is high on the list, my previous car was a 80hp 1275cc, stiff on the springs, 3" centre exhaust etc; fun when I built it, but I've had that one for 8 years and did not enjoy taking it out the last 3-4 years due to the harshness. 

 

Today I've at least split the transfer case and given the block a quick brush up to see what's what;

 

How the case came off: 

 

Showing how the crank adapter is attached:

 

 

Turns out there is no real 'adapter plate' but just a top half 5mm thick aluminium spacer to fill the gap between gearbox case and engine block, oddly enough there was barely any sealant on this.

 

 

The drop gear teeth seem okay to my untrained eye, but am I correct to see that this bearing is done? 

 

 

Gave the crank a quick clean with scotchbrite, the tapered end does seem to have some pitting on this side, not sure if thats of any concern?

 

 

After cleaning the block I noticed the water pump has an odd hole in it. Was planning to replace anyway 

 

 

The exhaust also looks a lot more dodgy on the inside than it looks on the outside (as it has coating there)

 

 

Overall it seems the important bits to this conversion are in decent nick, im just a tad puzzeled by the sloppyness of all the different sizes/materials/heads of bolts used. Most in the transfercase were barely hand tight as well.

 

Ill replace any service part, bearing, gasket and bolt anyway, but it makes you wonder of the level of craftsmanship/attention to detail that went in to it. At least the crank adapter looks solid.

 

For now im putting the block back together before stripping further, as Id like to get an idea of how it sits in the engine bay.

Edited by Spherix, 30 January 2021 - 11:18 PM.

[stoneface]

My adaptor plate is just thicker and the crank adaptor bolt flange is thicker. Otherwise the same principle as yours.

 

The hole in the water pump is normal, well it is on the x-flow. But I got rid of it and went electric.

 

For comparision, the dimension from the bottom of my block to top of oil filler cap is approx 400mm. The gearbox length from where the transfer case bolts on is approx 508mm plus and inch or so for the pullys.

 

Mine just fits under the bonet with a small area of the strengthening brace removed.

[Spherix]

Ah thats a good indication... for it not to fit! If I measure from the transfer case to the edge of the sprockets, I'm at 520mm, but height wise from bottom of block (top of gearbox) I'm at 420mm for the top of the valve cover, but 440mm for the top of the cam sprocket. The subframe mounting on the clutch side is the default position, so the engine won't sit any lower than a normal gearbox would either at the moment. 

 

I'm not adverse to making a bulge in the bonnet, but if I can come up with any creative solutions to hide the engine without it, I'm keen to try. 

 

Had a closer look at this presumed dry sump pump as well; as you can see on the picture this is not a single module, rather 4 bits mashed together!

 

It looks like an oil pump, a custom machined block for oil feed to head, the distributor, and the old oil pump/dizzy 'housing' they sliced off the rear of the ca. Not sure what those small oil pipes are for at this point. It's not even 100% in line sprocket wise, so I'll be taking a closer look at this concoction later on as well. 

 

 

I'll be placing a Minisport order soon to get some rims sorted out on the car I'm building, I'll see if I can get their input on the clutch setup as well. 

[stoneface]

From the part numbers on the side it is a Ford Cosworth Burman oil pump.

 

I expect there is something like a ford pinto jack shaft inside driving the oil pump and distributor.

 

I can't work out the oil system from the photos, but, I would have thought the oil comes out the sump through the pump and around to the otherside of the block so it can go through oil filter then into the engine.

 

There looks like an oil pipe from the other side of the block which connects back to the jack shaft bearing and the clear pipe could be a drain back to the sump or bypass. I done think it's a dry sump system. Or...... I could be completely wrong.

 

[Spherix]

Yeah I'll have a closer look the coming days at the oil routing, going to the filter makes sense as it does have one on the inlet side of the block.

 

I was planning to hoist the engine in the car to get a better understanding of all the sizes and mods I may need to do, but current virus and weather situations are making it tough to get hold of a cherry picker! Instead I've made the decision to opt for new clutch/flywheel parts, I've spoken to some Pinto tuners and the weight of a complete Mini set up with a lightened flywheel is within the range of what they would deem 'normally drivable, but snappy'. I've ordered a pre-verto lightened flywheel (4.432kg), orange diaphram, AP racing clutch plate, lightened steel pressure plate and the lot of needed bolts, locktabs, guides, cylinders etc. that were missing.

 

Worst case I'll just swap out a lightened one for a stock flywheel. Total weight should come in around 6-6,5KG if I'm not mistaken. 

 

I took a further look at all the part numbers I could find on the head itself and the bin of parts that came with the engine. The more I look at it, the stronger I start to feel about finding another option to get fuel in, as the K-jetronik system is complex, fault sensitive (and expensive to sort out by a professional), the manifold looks like a bit of a turd in terms of welding, and the complete set just looks VERY bulky in comparison to some bike carbs or even the original manifold/carb. I'll have to have it in the car to see the space I can work with though, and I'd like it to not be too loud (or expensive...).

 

The main injection unit is a mix of BMW, Audi and VW parts, I have a VW Passat 'warm-up regulator', Audi 'auxiliary air regulator', Ford anti-run on valve, etc. Not a lot of these parts seem to be available new, or 'easy to order', making me lean even further to getting something standard or more modern 'off the shelve'. 40 Years since the invention of this thing has spawned a lot of new options at least, and the mix up of K-jetronik parts makes me wonder if I'll ever get it runnng nicely as I'm not familiar with the systems.

 

As for the head, despite googling the casting numbers I can't seem to get a definitive answer on what it's from. It's got various numbers on it at least: 70HM-6090-NA, 220, 72, 12. The main casting number on the camshaft also gives no results, 'H31' with a yellow painted band around the cam. Aside from missing 1 valve (I knew this) it's also missing the related bits like the spring. Springs are marked with red paint, can't find what that means either. I hoped the community for these was similar to Mini's, where even the most rare engine numbers are instantly found through google The head does seem to have some porting work done to it, but it's difficult to get a picture of it due to the soot/dirt residue in there at the moment. If it takes long to find a hoist, I'll at least dismantle the head and give it a good clean in the meanwhile.

 

The block's casting number is 70HM6015B-A, but apparently this is not the number to ID the engine with, that in turn is hidden under thick paint behind that oil pump concoction, so I'll take that off and clean it up over the next few days as well.

Edited by Spherix, 08 February 2021 - 01:46 PM.

[stoneface]

Sorry I can't help with pinto part numbers but looks like you're are making some progress.

 

I went fuel injection but initially so I could fit it all under a standard bonnet.

 

Back then the only option was a weber or lumination kit. The lumination was very long so I went weber. Nowadays there are more options.

 

If you go injection just make sure either you or someone close to you can program it.

[Spherix]

Yeah this freezing weather isn't allowing me to be in my workshop at the moment, as I had to move my electric heater to my second garage where I'm storing a Mini that has been sold, but doesn't have proper antifreeze in it at the moment, we've seen as low as -15 during the night at the moment hehe. Normally I keep it above 5 degrees in there, with a good sweater it's comfy even in winter  

 

That does leave me with a lot of research time, so for the time being I've picked up a set of 38mm Mikuni carbs of a GSXR 750, as these are individual carb bodies I can space them out to match the head porting distance, which in turn allows me to fab up an inlet manifold very close to the head so I have clearance to make an airbox and a cone filter at the end. Seeing as this was a 50 euro purchase and I've got the flange for the inlet manifold off the K-jetronik one, it's a very cheap option at the moment to get the engine going. If later on it doesn't run great (although I've read a lot of success with these carbs), I'll probably switch to a megasquirt ecu with bike throttle bodies or something along those lines.

 

I'll be taking the head apart soon so I can ID all the parts needed to bring that in good shape, and see if I can ID the camshaft in there. Someone on the Turbosport forums had a suggestion on reducing the cam sprocket size, by effeftively running a 2nd timing belt. One from crank to aux (dizzy/oil pump) where you'd use the normal sprocket on the crank and the cam sprocket on the aux to get the proper turning ratio, and then attach another smaller one to that one to run to an identical small on the camshaft to keep a 1:1 ratio. Overall not as easy as it sounds, as the alignment and tension needs to be guarded over 2 belts, and it might make me lose the space I have for the water pump belt. Good to have options in case it doesn't fit under the bonnet, but it may be easier to just order a fibreglass k-series bonnet to give clearance later on. Sure can't wait to get a testfit sorted!