fiat twin...update...help!

Post by **callyspoy** » Mon Dec 29, 2008 3:49 pm

hi folks, if you have looked in the other posts, i was looking at getting a fiat twin cam engine/box. well i have it now, which is nice. fitting kit, downpipe, prop etc all there, and for £300(plus another £20 for the radiator too.) my only real thing is i have no idea about the engine. are there any books that i can get that will help(bar guy crofts as i can't afford that sort of money!) i need to know all the bits about servicing too, what car parts are compatible with basic service(plugs, leads, points?)
any help would be massively appreciated my friends.
woohoo!
cheers
*Callum*
oh...one other thing, the front of the engine, water pipe where the thermostat is...what do you connect onto that?? i can't see anything on ebay and that scares me!

Post by dp » Mon Dec 29, 2008 5:28 pm

If you mean the T pipe there won't be a thermostadt under but you can put one from I think an MG midget there. You block off one side of the T and use the other as normal to the top of a radiator. Or cut the T off so you only have one tube coming out of the engine at the front.

There used to be a thermostadt outside of the engine that bypassed the radiator (as opposed to blocked the flow) until the engine had warmed up. Theory was it didn't strain the water pump. Quite an unreliable setup so most people just fit a normal thermostadt.

Post by **plastic_orange** » Mon Dec 29, 2008 5:31 pm

Post a picture and we could help. Normally the top connection is in the form of a T - just blank one side and the other to your top hose connection on the rad.
What is the engine out of? - Once you find out, just get a haynes manual from ebay. Best guess would be a Fiat 131/132 - I'm sure the manual covers them all from 1600cc upwards.

Pete

Post by **callyspoy** » Mon Dec 29, 2008 5:37 pm

okay, i will try and get some pics up soon, won't be tonight though as it's far too cold out there! keep 'em coming with help, it's all rather exciting!

Post by **Sidney'61** » Mon Dec 29, 2008 5:47 pm

In Jon Pressnell's book 'Morris Minor: Exploring the legend' there's a chapter all about the fiat twin cam conversion, might be worth a read.

Post by **Peetee** » Mon Dec 29, 2008 9:24 pm

A book which I have and you are welcome to borrow Mr Callyspot.

Post by **neiltomlinson** » Wed Dec 31, 2008 8:09 am

hi callyspoy
sounds a good buy to me i did this on marmite four years ago made all the mounts etc the thermostat is under 4 bolts by that T pipe i welded up one side of the T pipe like dp said

i dont now if you now but these engines get very hot so if i was you get the engine is a far to the battery tray as poss so you can get a large elec fan in i use a bubble fan out of a ford the outher thing which i did is is fit the thermostat but take out the middle [center] still keeping the outer pcs in hope this helps neil
PS do you now what the rad is out of

Post by **Peetee** » Wed Dec 31, 2008 9:47 am

Not only do I have that book buy I have an electric fan and thin radiator going begging too!

Post by **Innovator** » Wed Dec 31, 2008 1:08 pm

Cooling Fiats:-

In the early days of doing conversions we always used the external thermostat and had no problems. However Robin wanted a clean look and discovered that early Fiats had the stat in the head and that the common BL (ie Minor / Mini) stat drops into the head. These stats were cheaper to replace if required. However this stat in the head setup required a completly bled coolong system. It would not self bleed. But once bled gave no problems.

The engines dont actually run hot its more to do with airflow AWAY from the rad. We always used a Marina rad with a Sherpa deisel core (denser fins).

It doesnt matter how much air you ram into the engine bay, it needs somewhere to go. I once did a pressure map (ie comparing pressure above and below the bonnet, using a homemade manometer) and discovered a massive build up of pressure under the bonnet above 40mph. Cutting a couple of vents at the areas of highest pressure difference made a huge difference to the cooling. I also noticed an increase in front end grip in high speed corners.

However our parents twin cam Minor coped with towing around France in summer without bonnet vents.

Post by **bmcecosse** » Wed Dec 31, 2008 9:08 pm

There should be plenty of space for air to escape the engine bay - there are large holes each side at the rear of the bay - even if the larger engine 'fills' the space bewteen the chassis legs.

Post by **rayofleamington** » Wed Dec 31, 2008 10:05 pm

Cutting a couple of vents at the areas of highest pressure difference made a huge difference to the cooling.

The BMC 'works' rally minors had vents at the back of the bonnet (well some did anyway) so i've often wondered if they would help a tuned engine or big engine set up.

Post by **callyspoy** » Thu Jan 01, 2009 4:21 pm

has anyone got a picture of this T-piece please...

Post by **fsk658** » Fri Jan 02, 2009 9:09 pm

Hi callyspoy I finished fitting a 1600 twin cam into my pick up about 18 months ago I wish you the best of luck. It took me over 1,000 hours to complete including the restoration. I would recomend that the spare spout of the tee piece is blanked off but tap the blank so you can fit a temperature sensor in it to control your electric cooling fan it will look a lot neater. I got some parts from my local factor Bedford battery they were very helpfull ie Head gasket,Water pump, some parts you can get from Ricambio phone 01737 359842

Post by **Kevin** » Fri Jan 02, 2009 10:41 pm

There should be plenty of space for air to escape the engine bay - there are large holes each side at the rear of the bay - even if the larger engine 'fills' the space bewteen the chassis legs.

It doesnt matter how much air you ram into the engine bay, it needs somewhere to go. I once did a pressure map (ie comparing pressure above and below the bonnet, using a homemade manometer) and discovered a massive build up of pressure under the bonnet above 40mph. Cutting a couple of vents at the areas of highest pressure difference made a huge difference to the cooling.

I would take note of John's comments as they are based on years of experience using the fiat twin cam engines.

Post by **bmcecosse** » Sat Jan 03, 2009 12:49 am

I suspect it's more likely there was a negative pressure above the bonnet - caused by airflow! If the manometer was simply reading above/below bonnet - then you would only get the difference in pressure -and not necessarily that there is a 'high' pressure under the bonnet. If there was -it would make a useful supercharging effect perhaps !

Post by **jonathon** » Sat Jan 03, 2009 11:06 am

Totally agree with John on the airflow causing issues with the under bonnet temperature.
We had a bonnet loovered for a turbo application (K Series) and recently we have a customer with a 1300cc supercharged A series who cound not stop the motor overheating. The mod was done by Vee Max so they are not strangers to the conversion. The bonnet was modified with four louvres between the bonnet hinge and center of the bonnet, since fitting this he has had no problems at all.
At speeds above 80mph the bonnet /enginebay does become a huge air collector and as John says the car will go light at the front end.
We did quite a few tests at Milbrook on the high speed bowl and found that fittig the spoiler reduced this effect dramatically. Our driver lapped the bowl 3 times 'no handed' (under instruction) at just over 120mph and the car was rock steady.
A combination of louvres and spoiler ( maybe track use only ) would be an ideal set up.

Post by **Innovator** » Sat Jan 03, 2009 9:59 pm

I did have a sump guard on my van which effectivly blocked off between the chassis legs.

The pressure differece could be caused by negative pressure above the bonnet, the manometer would not tell this unless I had one end in the car for example.

However if this was the case then I doubt if I would have noticed the difference in front end down force.

According to Vizard I think you only get a useful ram charging effect from pressure at above 100 mph, where as down force is more noticeable due to the large bonnet area. I only had about 0.25 psi pressure difference but consider the area of the bonnet.........

I did find that the place for the holes / ducts was as close to the front of the bonnet as possible. The air hits the front of the bonnet and is forced upwards creating a low pressure area.

Many people put vents at the rear of the bonnet under the wind screen. This is a high pressure area above the bonnet. The windscreen acts as a blockage and air stacks up, creating high pressure. Modern cars have their heater vents here. When I did my pressure map there was higher pressure on top of the bonnet at the rear of the bonnet. Vents or louvres here will only help vent under the bonnet at low speeds or when stationary.