Cletus' 68 Plymouth Valiant

[cletus]

On 20/06/2022 at 10:47, cletus said:

 

I think it has more boost than it should do

 

 

Fuckin dick, no wonder it did surprise wheelspins  

 

[cletus]

Thanks to the replies in the tech spam thread which basically reinforced what I was thinking, which is it doesn't have enough air flow and needs a better fan

I thought I'll live with the fan noise if that means I can actually drive it 

So I embarked on the mission of finding an engine driven fan that fits

Found the one I wanted on an NZ website , sweet, ordered it. 

Nope, " no stock sorry"

Bugger.

 

Found a different supplier who had one, ordered off their website

"Sorry, no stock, they might be here in 3 weeks? " 

 

Poos. 

 

 

Local guy had a plastic flex fan , I didn't want one of those as they are a lot deeper but meh I'll give it a shot , chucked it on, needed a bigger spacer so the blade cleared the alternator. 

spent ages rummaging around for some bolts

Started it, ran for a bit, moves heaps of air, good 

Gave it a rev to about 2500, the inch or so clearance at the bottom became 0 clearance and the fan hit the tank and broke the tip off one blade 

 

Ah yes that's why I hate these fans 

Luckily no damage to the radiator apart from some dinged fins 

 

 

 

 

Found a stock 245 steel fan I had in a box under the house, chucked that on, it will do for now and I'll find the one I want 

I think with a shroud on it should be OK,  the mechanical fans move heaps more air. It still creeps up at idle in the shed but no shroud and a slower fan speed than stock due to pulley sizes are the reasons I think

[cletus]

an update to my cooling system woes

I was convinced a fan shroud would fix my problems so I came up with an idea of what I wanted, and @RX FORD made me a nice tidy shroud and overflow bottle combo 

It made it better, thermostat opened at 180, I drove it around for 25min and it went up to 210 and stayed there. When I got home i opened the garage and left it idling for a minute to adjust idle, and it got hot and boiled 

 

I resisted the barry urge to remove the thermostat completely , I'd bought a 160f tstat so I put that in, and put a restriction in the bypass hose in case that was making the coolant do laps of the engine instead of the radiator 

 

Better again, tstat opens at 160, it went to 180 and stayed there for 10min driving around, I pulled over and it slowly crept up to 195 

 

So it's better, but not fixed. Bearing in mind this is a cool night and just tootling around slowly, it's still too borderline

 

I've got a stock 318 fan which has more aggressive angle on the blades which I might be able to fit if I remake the lower mounts on the radiator. 

 

Otherwise I'm running low on ideas. Maybe a small auxiliary radiator with an electric fan on it, or maybe I need to give the intercooler the heave ho as it's not helping airflow 

[cletus]

Under maximum jandal it squats more than the big bum girls in the fembot thread, and despite having about 80mm of clearance at ride height, the driveshaft would rub on the back of the tunnel which was not ideal 

 

so I made a pinion snubber bracket, it needed a reasonable amount of offset to make contact in the middle of the bit of floor that is designed for such activities 

Now it can have full power applied in the  forward direction which results in rapid transitions from one area to the next which is most satisfactory 

 

 

Did more mucking around with the overheating issue as well. Tried restricting water flow, it didn't make any noticeable difference 

Checked temps of top vs bottom tanks, I'm not sure how accurate the temp gun is or how much of an area it measures but it seemed accurate ish on everything except the radiator, ie it said the top tank was 28deg and I couldn't hold my hand on it  

It did suggest that the bottom tank was very hot at the same time, over 100deg, which is next to the exhaust , so maybe air temp affects the reading? Coolant temp was less than this at the time.

Next plan is the V8 spec fan, improve sealing around the shrouding, and something to keep exhaust heat away from the radiator  

 

[cletus]

OK

V8 fan and sealing around the edges of the shrouds made it better

Good enough that I drove it in total over 100 miles over a couple of days and it was pretty good, doesnt go over 180, at open road speed it's mint  

Today I made a heat shield thing between the exhaust and radiator  

Still gets hot and boils at idle though. 

 

So I'm pretty sure air flow is the problem 

So next will be try it minus the intercooler, I'm picking that will make the radiator work better, plus then there's space for a big electric fan on the front 

That will mean I'll have to redo the piping and swap the rad hose to the other side of the top tank. Dumb. 

 

Anyway, have some pics. 

 

[cletus]

 so I can keep track of what I've done:

Things that did not work or made negligible differences

10" elec fansx2

Plastic flexalite fan

245 fan no shroud

245 fan with shroud 

318 fan with shroud (probably most successful fan so far)

Derale 6 blade stainless flex fan

180deg thermostat

160deg thermostat 

No thermostat 

Restrict flow through hoses 

Seal edges of fan shroud 

Make fan shroud 360deg

Heat reflective stuff on rad tank, bottom of shroud 

Heat shield exhaust from bottom rad tank

Bigger bottom pulley to speed up fan and pump 

 

Im getting tired of working on it tbh. 

 

 

Only options left are- auxilary radiator and fan mounted somewhere . Probably under left front guard. I think this will be the most practical /cost effective option to try

Or

Remove intercooler so it doesn't block rad and allows a fan on the front . I want to have/need some sort of intercooler though, so would need to redo piping and buy intercooler and heat exchanger for water to air ($$) or buy water meth system (also $$)

 

 

 

[cletus]

Can also add to the list of "probably slowed the overheating but did not stop it" 

Heater core auxiliary cooler, this showed an 18degree difference in hose temps between hot and cold side 

 

Removal of intercooler.  

 

Side note at idle there is a warm breeze of 54 degrees coming out of the turbo