My Gordini head conversion

I thought I would start a fresh build on this, as my other one is full of bloody photobucket images!

I'm going to be doing this in stages over the summer, so when the bad weather comes I can pull the engine out, swap the cam, clutch, head etc.. Over then drop it straight back in.

The plan is to use the DTA ECU and run this on igntion side only for now, so when it comes to swapping the head, I only have to concentrate on the fuelling side of things to get it running.

So the spec, Ported Gordini head, C1J water pump, reusing my short block that's just been rebuilt, equal length manifold, custom inlet plenum, k series 52mm TB, running semi sequential EFI on DTA ECU, 550cc injectors, FMIC with fabricated duct from the bumper and exit duct running underneath the sump to draw the air out of the IC. Sealed air duct into filter to hopefully gain some positive pressure before the turbo, turbo spec undecided yet....

All I have at the moment is this blurred pic of the manifold, but hope to have this finished over the weekend and some better pics! :agree: then the next job is the inlet plenum. :D

This is what I'm watching with great interest! There may still be a pic or two of this conversion done by others on here. Also I kniw Karl Darby shire (karlos) on here is gathering bits to do this conversion.

Keep the thread updated Matty!:D

Yeah found pics on here, but couldn't find many finished ones.

I will be trying to do a kind of a step by step of what needs to be done, although I'll be learning on the way!

After the mini bike head swap, this ones seems quite straight forward at the moment. The main thing is that everything must be able to be put back to OE, so no chopping of bodywork etc..

if you take a pick-up from the camshaft fuel pump lobe you can run full sequential injection

That was the original plan michael, althoug. I was going to turn the dizzy into a cam phase sensor. But when I looked at the price of an ecu capable of fully sequential I decided it wasn't worth the hassle. Nearly double to price, I was going to runs cops too. It might be soemthing for the future, but for now semi sequential should suffice. :agree:

The exhaust manifold is all finish, and work has now started on the inlet and water pump adapter.

I'm struggling to get the damn timing chain pulley off the crank though to get the cam out...anyone know if they are just a push on fit, or is there something retaining it before I put a puller on it?

A work of art as per usual Matt! :agree:;)

Thanks mate. I've started on the inlet manifold now, lots of re-jigging of radiator, alternator etc... positioning but performance is taking priority. The main plenum body is done, so it's just injector positioning and sorting out the TB position now, the TB will have to wait until the rad is in place.

Does anyone know the route the water takes through the head and engine? I am thinking of running the standard water inlet from the pump, but having the outlet on the other end of the head. I am not sure if the water needs to take a double pass accross the head to cool efficiently or not?

I know the head casting needs a slight mod to partition off the inlet and outlet, as this is on the 'wrong end' but other than that I'm not sure the route the water takes through the block etc...?

Probably 15 years ago I looked at this while my engine was apart and discovered that the normal water pump end of the block at the rear doesn't flow or cool all that well. Big Jim did a modification to help that. I've forgotten what. It may have helped reduce the piston expansion and rubbing that more often happens at that end.

Can you look at the C1J head and pump, see which way it flows?

I will get some pics. 👍 it flow in the bottom of the pump and out of the top.

So here's the C1J head, by the looks of things the water goes through the small section then through the square hole in the head gasket then down through the block?

Does it just then comes up through the holes in the head gasket to the head?

Just trying to work out whether running it out of the clutch side to rad top would cause any issues like you say of a one cylinder not getting any flow past it.

Yeah, it looks like you can't do what you want to as the water will go only through the head.

As it is, it circulates into the block then up through the holes, as you say. Or the other way around. I don't recall which way the pump turns or the impellers direction.

You'd perhaps have to make up bespoke ends and restrict the flow through the head so as to get sufficient through the block. Then it would flow through both separately, and maybe block the holes from block to head.

I've managed to get the pump near enough in the original location now, and have access to the outlet hoses, so all will be left as standard where I can. I will probably end up welding 90 degree outlets onto the water pump to give better clearance on the hoses.

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And it looks like also doesn't align with the bottom pulley.

I recall people fitted an electric pump instead. The OE pump changes speed with revs, don't know if the electric ones can or if that matters.

Yeah I just need to space the bottom pulley out. The alternator needed moving over anyway to make room for the plenum, so not too bad.

I run an electric pump on my other car, and it's very good, much more efficient cooling than a manual pump, and great when doing 1/4 mile runs as you can leave it running and fans on to cool the engine between runs. I just run mine fixed speed, but speed controller can be used.

I'm trying to make it all look like I should be like it from factory, so everything kind of where it should be on a standard C1J...think I'm making life difficult for myself. :laugh:

Water pump adapter is now finished, quite a bit of head scratching involved!

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I ended up added an extra tab onto the rear section of the water pump as two of the bolt holes were too close where I have off set and tilted the pump.

Injector bosses no added to the inlet stubs...bloody tight for space! I'm going to have to scolop out the plenum top to clear the injectors now. :wasntme:

The next job is fitting the new rad, then I can modify the rear section of the water pump. Most of the outlets need to be moved to avoid the plenum.

Some more done...Peugeot 205 rad modified to fit in. It's all getting a bit tight for space at the front now. :laugh:

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Fits nice and snug, all I needed to do was check the plenum all fit before final welding of the plenum. Next job is to finish the plenum, and the TB, and fuel rail.

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Started to get some paint on it.

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That might be the first one I've seen in all these years that might be done right; with the larger intercooler not in front of the rad, but side by side, as Renault did it, but rotated 90°, and with a bigger cooler.

Will that 205 rad be big enough? Clear the alternator? Do the oil cooling?

Maybe if it's marginal, you could fit a grill in the bonnet to let more hot air out?

Cheers, I was thinking of using the small section I cut off the rad as an oil cooler. It's about 600mm long X 40mm X 40mm so quite a large cooling area, although I have heard that they are not needed too much? I Al ways think it is better to have one and fit a thermostat than not.

The rad volume works out the same as the standard rad, but I'm hoping that due to being in the airflow better and not half if it behind the crossmember it will cool slightly better. I think I will try and have slightly more cooling capabilty too, so the standard swirl pot will be replaced with a 1-1.5L capacity one.

Ha the alternator has been a complete nightmare! I have exactly 125mm betwen the rad and engine block, the the standard one is exactly 125mm, so I will get a Daewoo matiz one instead, as they are V belt and 65A and only 100mm diameter and quite a bit shorter too. I was hoping to reuse the standard one, but it's just too bulky.

Nice :)

Do you know the flow, more or less, through the new rad compared to the old one?

If it's a lot less flow resistance you may need to put a restrictor in series with it or each of the other two parallel cooling loops, being the heater matrix and the turbo, will be bypassed by it and too little water will flow though the other two and the heater matrix will not heat and the turbo will not cool.

It looks, by the extra width and less height, to be likely to have less flow (more flow resistance), and you may need an appropriate bore restrictor in each of the other two loops.

That's a good point I hadn't thought of that.

I suppose I could flow test it before fitting it, but I guess it would all be trial and error with restrictor sizes?

I guess if you could flow the new and old rad and generate some comparative data, you could then make some estimates of how much flow adjustment is needed, if any. Then some more flow testing with restrictor(s).

I think an oil cooler is probably a good idea. During hot summer, pushing on though lanes, my engine would have sump oil temp of about 112°C. And that's with the built in cooler keeping the sump output down to about 90°C.

I have a flow bench, but it will take some time to get it up and running again, so I might just go down the trial and error route.

Having an oil cooler will also help keep the engine temps down. :agree:

I managed to get the cam modified today, it ended up be very straight forward.

Top Gordini stock cam, middle, modified Gordini cam, bottom C1J stock cam.

Finally found some spare time to crack on with this, in prep for retro show. Engine bay mocking up going well, slowly but surely running out of room for everything to fit in. :laugh:

I'm still waiting for my new rods, paddle clutch, and cam bearing to arrive, so the engine in staying in for now. It would be nice to get it all swapped over and back in for good, as that would be a major mile stone reached, but I'll plod on for now.

Final bit of machining finished on my piston buttons today...still no rods! :mad:

New alternator has arrived, so I can get cracking on making a bracket up for that over the holidays.

Awesome build Matty. Just noticed your going for DTA ecu. Are you taking it to EFI parts for mapping?

Cheers, feel like I'm getting somewhere with it now.

Change of plan on the ECU front at the moment, I'm testing out an ecu that I am planning on using on the EFI kits for now. If it becomes a ball ache, then I'll go down the DTA. Unfortunately EFI parts are a little far away for me. :crap:

I'll map most of it myself, then take it to my mates house to get him to finish the rest off, he has a RR,flow bench machine shop at his house. :laugh:

A rolling road at your house would be cool! Bet the neighbours love him!😁