MX5Ireland

I've got a late 1993 NA 1.8 FM II. I've got my stuff together for a coolant reroute on the cold side of the engine, including the spacer from Whisper, the Kia thermostat cover, flexible radiator hose (1m long if I remember rightly) and another few bits and bobs. Oh and I have the FM crossflow rad too so the radiator neck is right at the end of the radiator, on driver's side.

I'm staring into my engine bay though, wondering how on earth I'm going to route the hose without it rubbing against fuel lines, or brake lines, or my braided clutch hose, etc. I'd prefer to keep the manifold support bracket, but not sure I can. Would be great to see how others with a 1.8 have routed the hose. The vast majority of photos on the web for this seem to be of 1.6 engines which it looks like they have more room on the intake manifold side. If anyone in the Mayo/Sligo/Roscommon/Galway area has done it on a 1.8, it would be great to see it with my own eyes. I'm in north Mayo.

I'm sure you've seen this
http://coolant-reroute.com/

Yes, thanks Pops, but unfortunately it doesn't seem to show examples of hose routing. That's what I'm looking for really, for 1.8s, and ideally I'd like to get a good look at one in person.

I presume that's Whisper's website is it? In fact I'm pretty sure that site didn't exist when I first started researching my reroute, but yes I have seen it since then.

not sure if you've seen these pics from Whisper :
viewtopic.php?f=14&t=6938&p=56138#p56138

Yes, thanks Steve. That's a 1.6 though, which I think has more room beside and under the inlet manifold. On my 1.8 there is much less room. I'll have to see if I can make my braided clutch hose sit in a different position (don't want a stainless steel braid rubbing up against coolant hose!) and I think I'll have to bend/replace at least one hard brake pipe. The latter isn't too big a deal as I have an adjustable brake proportioning valve to fit anyway.

I'm away with work for a couple of days but I'll have to remember to take a few photos of my engine bay when I'm back.

I've done it on both the 1.6 and 1.8. The hose will rub lots of things, no way around it. I ditched the mani support and the carbon canister. The hose makes changing the oil filter harder too.

Thanks andrew. For years and years I have always replaced the oil filter from below, after removing the manifold support bracket. I often combine it with a front brake service - run the engine up to temp, jack up the front, drain oil, service front brakes, remove oil filter (which has now cooled a bit) etc, etc. I've often thought about installing a remote oil filter relocation kit, but never got around to it yet. Besides, I don't like adding unnecessary weight to the car.

Do you still have the 1.8? What part of the country are you in?

This might help, if you can understand him
https://youtu.be/Xqf91ig1CqY

Thanks Pops, good suggestion. His installation is certainly a bit less neat than what I'm looking for! Also his hose routing looked a bit high, which I want to avoid so that I avoid problems with air in high points in the system - want to try to make sure that the radiator cap is the highest point.

Youtube led me to this video though, which I've actually seen before, and it's an installation guide for the IL Motorsport reroute kit, but after watching it again it looks like it could suggest a good place to route the hose too. I'll have to get back out in the garage and give the job another good coat of looking at!

https://www.youtube.com/watch?v=1y4Hf0B_cjk

Put a piece of steel tubing in the pipework with a bracket welded on and attach it to the manifold.

or some large P clips?
http://www.ebay.co.uk/bhp/rubber-lined-p-clips

Yep, thanks for suggestions guys. I spent some more time on it over the weekend. I disconnected my fuel lines, braided clutch hose and a brake pipe to do a test fit of the new coolant hose. I think I can keep my manifold support bracket, which I prefer. The coolant hose will need to be strapped to the manifold to stop it rubbing against things when the engine moves - chassis, fuel/brake pipes, etc. But I think it will work.

I did get this done in the end. It turned out that the flexible coolant hose which I used between the back of the head and towards the radiator was a little bit too rigid, which made installation tricky. With that hose already attached to the new thermostat housing, I couldn't get the housing attached to the back of the head as there was too much lever action from the hose, pulling the housing out of true. So I fitted the housing first and then slid the hose in, beside the engine (cold side) around the back and onto the housing neck. (A lot easier said than done!) The hose wall was a bit too thick too, making it difficult to get a jubilee clip into place on it at the rear of the head. There is an existing coolant connection on the head itself, for a smaller coolant pipe (probably to the oil filter boss, but I don't remember exactly) and the new, main top coolant hose was snug up against it, making it difficult to get the jubilee clip into place. I had to carefully lever it with a screwdriver.

At the radiator end of the new hose, it needed to come up about 100mm/150mm to meet the radiator top neck, but stay low until that point to keep clear of the throttle linkage. This is an FM 'crossflow' rad so the neck is right at the end (driver's side) unlike the stock Mazda radiator, which is good as it kept the hose nicely clear of the throttle body/induction pipework. What I did was fit a 45degree elbow silicone hose at the rad, cut to size, and then a 45degree elbow metal pipe between that and the 'flexi' radiator hose. That all worked well, although I still need to sort out a better solution than heavy duty cable ties (!) for holding that flexi hose up against the intake manifold, away from the chassis.

I'm pleased with the result. I've only driven the car on road, not track, since I did the work last year, but it seems to be basically leak free and working fine. I've noticed that my rocker cover gasket no longer seems to seep oil, which it always did before, even before I put the turbo on. So I've now put that oil seepage down to uneven expansion due to uneven heating in the engine.

Oh and I removed the old thermostat neck from the front of the engine and installed a freeze plug in its place. The coolant was drained anyway so I did a cambelt change and the water pump while I was at it, which had just started to weep anyway. I much prefer the neat look with the old thermostat neck removed rather than just capped.

If I did the job again I'd look for a more flexible coolant hose with a slightly thinner wall, but apart from that, I'd do it the same again. I used Whisper's thermostat housing and a Kia thermostat housing cover. All very neat and fitted well.

I'll see if I can upload a photo or two. What do people tend to do for putting photos on this site? Just put them in Dropbox or some other image hosting site and include the image URL?

[Edited to add that 45 degree elbows also keep the radiator top hose away from fouling the throttle linkage.]

great stuff, would like a look at those pics.
You can upload them direct or link to them on some other image hosting site, heres the instructions :
viewtopic.php?f=9&t=5157

Ok, here's a few photos... :)