16V cambelts and hoses

[rsfruitbat]

Whose cambelts would you recommend for a competition engine and where would you get them from.

Planning to go to silicone hoses. Anybody got any experience of them. Any suggestions on how to do the hoses that arent covered in the sets i.e. from the expansion bottle down to by the clutch slave cylinder. Spoke to Alex Poulter so far but the kit he can get isnt complete.

Thanks Guys

rsfruitbat

[PETROLHEAD]

Hi mate

i think so long as you stick to a good genuine brand, such as Gates, Dayco or Conititech you won't go far wrong.

If you run higher valve stress's and more compression, yes there's transference of extra effort to the belt drive, but i think changed more often would be best practice, i don't know of a belt that is made for higher tensions for our engines.

Do you suffer with stretch at all Ade?

[Spacenut]

I have been using silicone radiator hoses for the last 10 years and thermostat to inlet manifold for the last 5 years, with no apparent problems. I have used a couple of pre-formed hoses for the thermostat to radiator transfer pipe connection, but the remainder are all straight lengths of the correct diameter and cut to the required length. That does leave some surplus of various diameters but overall the cost is reasonable. I will probably replace the heater hoses and the smallbore pipes to the expansion tank with silicone as well, probably at the next coolant change interval.

I've often wondered whether it would be possible to convert a boxer engine to use timing chains. There are plenty of examples where a chain drive has been updated to toothed belts, but only one (as far as I know) where the manufacturer has thought better of cam belts and replaced them with chains - Lamborghini.

To my mind, cam belts are a matter of manufacturing convenience and engine noise reduction, neither of which should bother a competition driver!

There again, gear driven cams would be even more fun, could a gearbox cog be keyed onto the crankshaft and some bevel-gear jackshafts sent to each cam box??? Imagine what that would sound like at full chat!

Um, sorry. That wasn't what you were asking about was it

Lauren

[rsfruitbat]

Thanks for replies so far.

I do get some stretch but I dont have a great deal of room to play with as the block got skimmed quite a bit for the engine rebuild. I may end up going to large diameter pulley wheels!

Lauren - who did you buy your hoses from?

rsfruitbat

[PETROLHEAD]

I think the larger cam pulleys would only serve to perpetuate the tensions and stretching issues in the long run if still using stock quality belts.

Unless the block skimming has shortened the belt route sufficiently to be of concern to pulley positioning and timing? but i shouldn't think so,

has it?

[rsfruitbat]

Hi Shrew

The block was skimmed a lot, from memory about 2mm was taken off each face?
It was an oversite that I made when having the pistons made. I am using a shorter stroke crank than a 1700 so instead of getting the gudgeon pin lowered in the piston I skimed the block. The amount of slack generated in the belt by doing this has to be taken out by the tensioner. I have already elongated the slot as far as I consider I safely can. Bigger tensioner pulley wheels just move the belt further and help take up that slack. I think.

rsfruitbat

[Spacenut]

Yipes, 2mm off each block face is a lot!

I agree, bigger pulleys would recover the slack on the belts, and bring the tensioners back into play. I chickened out of fitting the Alfatune engine into the Green Machine until I can sort out a similar issue - my engine has had 1mm taken off each block face, and 0.5mm off each cam carrier, so that the standard twin-lobe cams can be re-profiled for higher lift. So I've got the same tensioner problem, with the nearside belt running too close to the water pump for comfort. My plan is to get 1.5mm thick cam carrier gaskets made up in aluminium, and then use Alfa 101 series tappet shims to bring back the valve lift. Or I could use Ducati shims. Apparently only the Alfasud, 101-series cars and the Ducati share the same 8mm valve stem dimensions...

One other advantage of larger pulleys is that you would reduce the tension load on the cam belts - the larger diameter pulley would confer more mechanical advantage.

Lauren

PS - the majority of the hoses I have used are Samco, but recently I have been buying hoses from Advanced Fluid Solutions (AFS), which are cheaper than Samco and seem to be decent quality.

[Spacenut]

...of course when I said increase the diameter of the camshaft pulleys, I also meant to say the crankshaft pulley as well - otherwise the 2:1 timing ratio between the crank and camshaft would be lost.

The bit about the mechanical advantage still applies though...

[PETROLHEAD]

Just to make sure i've understood correctly, and vice versa, i would agree on the principal of increasing the size of the Tensioner pulleys, that would be the best answer i'm sure, and allow you the opportunity of some trick alloy bits too!

[Spacenut]

Ah. My bad - I thought Fruity meant camshaft pulleys. Yes, I agree increasing the size of the tensioner is one way to do it, but alas not for me, as all it would do is force the nearside cambelt even closer to the water pump housing

Hope this trick works for you Fruity.

[rsfruitbat]

Thanks Lauren

Have I ever told you the Nova was my first dream car?

Fruity

[PETROLHEAD]

Tom confirmed just today that they had to shave down the water pump housing on a couple of occasions for this very scenario,

It can (had to) be done sometimes

[adsblacksud]

Or you could fit a remote electric water pump as I have - I'll be running my motor in anger in a few weeks so I'll advise if it is adequate - or not..

I have also fitted silicone hoses so I will post a couple of photos this weekend

Thanks

Adam

[rsfruitbat]

Thanks Adam that would be useful.

I have thought about going electric but still unsure about it. let me know how you get on.

I have reduced the webbing on the pump to ensure enough clearance

rsfruitbat

[BS25]

I've been running an electric water pump on my race car for 4 years now - no problems at all.

[adsblacksud]

Hello Adie,

Apologies in advance for the photos - black hoses in a black car in a dark garage..
For the stretches that go to and from the heater matrix I used flexible silicone tubing that I bought from ASH in Scotland.
On the drivers side it looks like this:-

with one of these to tee off the 8mm bore tubing to the expansion tank as I wanted to avoid using the crumbly plastic tee pieces and Icouldn't find a 16x16x8mm aluminium or stainless one anywhere:
http://www.ebay.co.uk/itm/Revotec-Self- ... XQNOZRC6Rr
On the passenger side it looks like this:-

With one of these equal bore tee pieces that is much nore robust than standard.
http://www.ebay.co.uk/itm/LPG-AUTOGAS-T ... xy8F1RFnT0

Thanks,

Adam

[Spacenut]

That looks a lot tidier than my soldered plumbing pipe

[Spacenut]

Have I ever told you the Nova was my first dream car?

Don't think so, but it's a common affliction! The trick is not to actually fall into the trap of buying one and being disappointed because the beauty is only skin deep. You know how the saying goes - never meet your heroes

Lauren

[adsblacksud]

Lauren,

If you saw the standard of my soldering it would make you weep..

[rsfruitbat]

HELP

got a set of silicone hoses which to be honest I am a rather disappointed with at the moment. That will probably be phone call tomorrow. I sent them all my hoses so they could give me the best match. If this is best I will be fitting my old hoses back on
Just got in from the garage and at the moment I havnt found one hose which will fit straight on. most need shortening but the big one across the block looks too short.

I have fitted an AlfaSud stat housing so the stat can be removed for better cooling flow.
Is this very different from a 33 16V one?
does it sit slightly more towards the centre of the block?
does the connection that comes out the back for the heater matrix comeout angled up?

Any help pics appreciated before I have to go out and buy one just to see what it looks like.

Pretty desperate to get this sorted as engine is on the floor after a rebuild and we have got an entry for a rally on April 23rd

Many Thanks rsfruitbat

[adsblacksud]

RS
I have a Sud one on my 16v engine and there are definitely differences in the layout and angles of the connectors compared to the 33 one as you describe.
I still have my 33 one and I'll take some photos when I get home from work tomorrow.

thanks

Adam

[rsfruitbat]

Hi Adam.

Thanks for the offer but I had a rummage through the lockup this mornimg and found a very old 33 stat housing.
Main differences are:
the inner rear connection for the across block big hose is longer than the Sud.
the rear connection to the heater matrix is angled upwards.

Whilst trying to find a new one today i was told that he was pretty sure that the same part was used on fiats which explains why it changed.

justsuds have come to the rescue with a new one.

also spoke to the hose supplier who was very helpful so hoping we can get things resolved in the near future and get the Sud one refitted.

thanks rsfruitbat

[Spacenut]

Hi Fruity - sorry to hear your first experience of silicon hoses was a bad one. I must admit I never bothered to look for Alfasud specific hose kits when I did mine (the radiator hoses had to be custom anyway), I just bought straight sections of the correct diameter and cut them to length. Fingers crossed you can have everything back together for the 23rd, I'm sure you can do it!

Lauren