Check your fan belt!

[neilbardsley]

It's the little things with these cars. My 356 arrived from the US with a notch style 838mm belt. It ran nicely in Germany in 2013 but I was having to watch the engine temp. This year I wasn't so luckily. I noticed before going to CLM that they car was heating up too quickly. I had replaced (with the same size and type as it came with) and adjusted but found myself having to tighten it up more and more to stop it slipping. The problem with this was that is descreased the gearing between the pulley and the fan. In additional to this the correct belt size is 825, v 838, which meant which also descreased the gearing between pulley/fan as well. All this meant that the fan was cooling the engine enough for the corresponding RPMs.

This caused me to have to run very slowly to CLM to prevent over heating and possibly was the cause of the problems I had with the generator. However, it's not clear if the generator bearing was seizing and causing these problems. I did fit a notched style 825 belt on the way to CLM but it failed on the way back after only 200 mile of driving? Another rookie mistake I made was to put the 'spare' shims between the inner pulley half and generator. I shouldn't of done this because it moves the engine pulley and generator pulley halves out of alignment. The 'spare' shims can be put between the out pulley half and the nut.

I'm now replaced with a V size 825 fan belt, again available from PRS, Roger Bray etc, and it's earlier days but the engine is certainly running cooler.

I thought that by replacing like, with like, I couldn't go wrong but, as MT told me, with these cars you should never assume anything about their history. Hopefully, this note will prevent someone else having the same issue as me.

[silverfox]

Thats very interesting, I am going to check my belt as it is the notched type and not 825. I found the v belt factory 825 would not adjust and did the same as you and copied what was on it when I bought it.
My 912 runs in the middle of the guage until you push on the motorway. I was the same going to CLM, had to manage temp by slowing down under 60mph and the temp would come back pretty quickly before pressing on again. I cleaned up oil cooler early on in ownership which was caked in years of debris and that made cooling more predictable. Contemplating remote oil filter which if put in the right place under the arch may give a bit more cooling. Planning for CLM 2016 already! Maybe a five speed box as well if any bodies got one that needs a rebuild?
I drove mine for the first time on Sunday since CLM, they really are rewarding cars, with every tweek they give you something back.
Paul

[alanchester]

Thats very interesting, I am going to check my belt as it is the notched type and not 825. I found the v belt factory 825 would not adjust and did the same as you and copied what was on it when I bought it.
My 912 runs in the middle of the guage until you push on the motorway. I was the same going to CLM, had to manage temp by slowing down under 60mph and the temp would come back pretty quickly before pressing on again. I cleaned up oil cooler early on in ownership which was caked in years of debris and that made cooling more predictable. Contemplating remote oil filter which if put in the right place under the arch may give a bit more cooling. Planning for CLM 2016 already! Maybe a five speed box as well if any bodies got one that needs a rebuild?
I drove mine for the first time on Sunday since CLM, they really are rewarding cars, with every tweek they give you something back.
Paul

Good stuff Paul,

Will we see you at Bo'ness this weekend.

Do you know if Porsche Glasgow/Edinburgh have a display on this year?

[silverfox]

Hi Alan

PC Glasgow and Edinburgh supporting the Bo'ness Revival again, Bill Drysdale and his team do a fantastic job on putting this event on every year. There will be a great liveried Martini 991 Course Car. I unfortunatly am not going to be there, am at a clashing event, the tenth Crofterra Pandemonia with the Highland Car Club. Hope you enjoy the Revival, looking for a sub 35 sec from Margaret, yes, yes I know she beat me last year - I will be back!
Paul

[neilbardsley]

Thats very interesting, I am going to check my belt as it is the notched type and not 825. I found the v belt factory 825 would not adjust and did the same as you and copied what was on it when I bought it.
My 912 runs in the middle of the guage until you push on the motorway. I was the same going to CLM, had to manage temp by slowing down under 60mph and the temp would come back pretty quickly before pressing on again. I cleaned up oil cooler early on in ownership which was caked in years of debris and that made cooling more predictable. Contemplating remote oil filter which if put in the right place under the arch may give a bit more cooling. Planning for CLM 2016 already! Maybe a five speed box as well if any bodies got one that needs a rebuild?
I drove mine for the first time on Sunday since CLM, they really are rewarding cars, with every tweek they give you something back.
Paul

I have a v 825 on my 912 as well. A remote oil filter isn't a bad idea but on my 912 I've never been worried by the temp or you should be ok to so that doesn't sound which right. I would consider finding the isssue before installing a remote cooler? Perhaps, consider some other things. What oil are you using? A synthetic oil shouldn't heat up as much and can operate at higher temps. Lots on here, including me, use http://www.valvoline.com/products/consu ... otor-oil/6 . You can get 5l for about £25 if find a bargin.

Make sure the oil is up to the high mark on the dip stick. More oil means more to spread the heat.

Check your exhaust value gaps .15mm?

If none of those idea help them someone who really knows what they are talking about will come along and help.

[alanchester]

Hi Alan

PC Glasgow and Edinburgh supporting the Bo'ness Revival again, Bill Drysdale and his team do a fantastic job on putting this event on every year. There will be a great liveried Martini 991 Course Car. I unfortunatly am not going to be there, am at a clashing event, the tenth Crofterra Pandemonia with the Highland Car Club. Hope you enjoy the Revival, looking for a sub 35 sec from Margaret, yes, yes I know she beat me last year - I will be back!
Paul

Good man,

We will put it down to beginners luck.

Take it there not looking for any cars for a display, not heard anything.

[Burma-Shave]

Damn! Forgot I was going to do Bo'ness this year. Too late now
Next year..

(Sorry Neil, will also check my fanbelt )

[neilbardsley]

Damn! Forgot I was going to do Bo'ness this year. Too late now
Next year..

(Sorry Neil, will also check my fanbelt )

You already have an external filter and your car runs very nicely.

Plus by adopting a kilt while driving you promoted cooling to the most important area!

[Mike Smith]

The Belt section is as important as the length

The correct belt is 9.5 x 825 - Porsche part No 999 192 006 50

[Burma-Shave]

Plus by adopting a kilt while driving you promoted cooling to the most important area!

Permission to use the 'crotch cooler' joke again please..

[silverfox]

Using Valvoline VR 1 20w50 Mineral Oil, valve clearances ok and oil topped up, good compressions and balanced cylinder leakage.
Temp Guage is fine all day at 70mph, press on 90mph plus on hot continental roads or M8 and the guage creeps up. Engine tray seal is not perfect and on the to do list. I thought they all ran hot when pushing on but would love to reduce the temp on these long tours and not just rely on my limited mechanical empathy.
May try a different oil although always been loyal to VR1, may even try the new Porsche Oil and see what happens. Other ideas welcome, I'm sure the solution is out there.
Good chat guys.

[Mike Smith]

First check that the gauge is actually reading correctly - Needle straight up in the middle should be 100c

IF (?) it is running hot - any combination of the following may be the cause

1) - Remember that ambient air temp will make a difference
2) - Is the Ignition Timing correct ?
3) - Is it running weak at high revs ?
5) - What Oil Pump do you have (Small or Large Gears) ?
4) - Valve Guides may be worn
6) - There may be crud on the Oil Cooler
7) - There may be crud over the top of the Heads and Cylinders
- Is the Rear Tin Missing- ?
9) - Is the Front Tin Missing ?
10) - The engine requires to be sealed into the engine bay - Are all the Seals good and doing their job ?
11) - Do you have the Oil Pump Protection Plate fitted ?
12) - Does the Tinware fit correctly (how many gaps do you have ?
13) - Has a previous owner added another Filter ? - If Yes - Where is the filter located (It should be outside the engine bay)
14) - The latest Fan blows more air - How many Blades have you got ?
15) - The latest Fan Housing (without the mesh) passes more air

For Motorway running - you might want to consider a higher 4th Gear or a change in all the ratio`s
I personally run a 4G in my old Standard `C` - On a 2,500 mile trip to Italy and back, running between 75 and 90 on all the motorways, it gave me 36MPG

[neilbardsley]

First check that the gauge is actually reading correctly [/b]- Needle straight up in the middle should be 100c

I bought a infra red temp gauge off eBay for £8. You can point at the engine slump plate and check!

[Burma-Shave]

Neil you need a Mainely dipstick guage - scroll to the bottom of here:
http://www.mainelycustombydesign.com/en ... nents.html

also useful at christmas to check the turkey is cooked..

[silverfox]

Great Check List Mike, car is running great, thanks again for your help. Since rebuilding carbs and fitting your diffusers I think the top end performance is better, creamy smooth delivery. Idle is smooth but can not get idle speed as low as I would like without running to lean and the accompanying popping and farting. I'll keep fettling.

I must check the guage accuracy and also do some work on the tin rubber and maybe some gaps in the tin. Got a good run at the weekend and I will report back. I am going to change the belt, as Neil said small things count.
Paul