Another fine piece by your good self. Keep going Dave, your solution is a lot better than the rubbish often supplied.
Paul

Cheers mate 

I really cannot believe just how bad this mechanism actually was   

The inlet manifolds I am using are the Short CSP ones. They are almost half the height of the standard ones and cost twice as much. I have seen a lot of comments about inlet manifolds, and there seem to be quite a few that fall well below the standard bore size of 40mm which means that any vapour traveling through them would be heavily restricted. Something work checking for when you order your manifolds.





I know I keep going on about the height issue, but when you see a Dellorto DRLA40 next to a Weber ICT34 hopefully you will start to understand why. Do not forget that my inlet manifolds are half the standard height, and my Air Filter is considerably smaller than the standard ones you get with the kits.





With the old manifold now off, we need to remove the studs so that the long bolts supplied with our much larger manifold can be fitted. If you recall the spanner and nut trick I explained earlier, the same needs to be done here, just taking a bit of care as these studs can be very tight indeed.





With the faces of the cylinder head cleaned, and new gaskets fitted, the manifolds were bolted into place. I know it would have been easier to bolt the carbs to the manifolds first, but I wanted to remove as much weight as possible when bolting to the cylinder head in order to achieve the maximum seal I could before tightening everything up. These manifolds do not have the balance pipe from one side to the other, and whilst it is used for the brake servo when this engine is fitted to a van, opinion is divided when there is no servo fitted. I only fitted the balance pipe to my old manifolds as the holes were there, but as these do not have any, I will not bother. What I will bother with though, are those green gaskets, as they are special thermal gaskets designed to prevent fuel evaporation when the engine is turned off. Not convinced that they will make that much difference, but for the sake of a couple of quid each, I couldn`t think of a reason why not.





And the moment of truth . . . . .   Phew ! They fit !





With both carbs now bolted down, I thought I should connect the fuel lines next because I did not want the open ends to leak whilst unconnected. When I ordered the Carburetors, there were a few options open to me as to how the fuel lines would connect, and I went for the type known as a Banjo, because I knew it would be easy to change if needed. They supplied me with the Banjo fitting shown at the top for an 8mm fuel pipe, somewhat larger than the 6mm pipe I had already rigged the car with, but all I needed to do was to obtain a M14x6 Banjo to replace it with. M14 is the size of the large hole, whilst 6mm is the pipe size. the picture shows the different size washers that also hold this in place.





With the fuel lines now connected either side, the list of things needing to be done was rapidly coming to an end. The Vacuum pipe has been connected to the Left Hand Carburetor, but as previously said, I will come back to that one later once I have proven or dis-proven a theory.





The arms were slid into place on the Hex Bar, but not tightened up yet as their position was yet to be determined. Very important to make sure that the Carburetor arms are mounted approx 60 degrees from the central throttle one. The Hex Bar was mounted on a rose joint at either end, and I liked this idea, however, I did not like the idea of allowing the bar to effectively "float" between the two rose joints as is the norm with most Hex Bar set ups. So I have bolted one end directly to, and hard up against the right hand Rose Joint, whilst allowing the threaded rod coming out of the left end as shown here, to be adjusted so it clears the rose joint and no more. This gives a really smooth rotation with zero lateral movement. Exactly what I was after. And that return spring? That was left to one side, because I do not think it will be needed - At least not yet.





Before attaching those vertical links, its important to make sure that the ends are wound in as far as they will go. One is a left hand thread and one is a right hand thread, and once fitted, adjustment is made purely by rotating the central bar. The small nuts attaching them to the Carburetor and the Hex Arm should have some form of nylock nut, or at least a blob of thread lock on them, as this can be a common area of failure. With those in place, the arms are slid along the Hex Bar to get the linkages as close to upright as you can.





When you are satisfied that you have full movement with nothing hitting or fouling anything, the Hex Bar Arms can then be locked into place.





The process is then repeated for the carburetor on the other side, making sure that nothing fouls. Once this has been done, there is one more check to do. Ideally, the linkages will be fully upright, but in reality, there will be a slight angle on them. There is nothing wrong with this, but it is, however, very important that the angles on each side look the same, else the Carbs will operate at slightly different speeds, which would not be good.





After a bit of fiddling with the vertical linkage adjusters, I have got it to a stage when I can hear a clonking noise from both sides when the throttle comes to rest. If both carbs are coming to rest at exactly the same time, its a good starting point for tuning. I have also determined, much to my relief, that the return spring on each side appears to work perfectly, and nicely closes each side with a reassuring snap.

Just the throttle cable to connect. One of the King sized bodges I made when I put the Type 25 lump in was to use the knackered end of a cable guide tube with a roller on it. I always meant to revisit this at some point, but life just got in the way, and if perfectly honest, it worked so well, I forgot about it. With the orientation of this cable now higher, I had to turn my bodged guide tube through 180 degrees, and again, liberally smear it with Chemical Metal to hold it in place. I will get another tube at some point, but its Sunday, the shops are shut, and there is no other means to attach this.





The foot pedal feels silky smooth, and the linkage opens fully with the pedal flat to the floor. There is only one more thing left to do, and that is turn the ignition on to see what happens. I give it a good minute or so to let the carbs fill with fuel before cranking it over. There are a few pops and backfires, but after a couple of attempts it has burst into life. It starts, it revs, and it just about ticks over.

Time to stop for the day, retire with a beer, and read up on some witchcraft and black magic

Or as you lot know it as . . .   Tuning and balancing.

A good write up there Dave, easy. See why folks get fed up with stuff they are sold these days.

Looking good Dave. You need those thermal gaskets, when I got my carb kit it just had card gaskets and the noise of fizzing fuel when I parked was something else.

How did the Monday morning phone call go?

Everything's looking very good and its interesting hearing in detail some of the issues, like height etc.

This is only a suggestion, but something is glaring at me at the mo, isn't sitting right and in view of the care and investment, needs sorting out... 

Soft materials like aluminium and similar alloys dont like to be under unessesary forces, specially
when heat stretching and twisting is involved, as they can and do strip easily.

This is one of the prime reasons that all heads have studs fitted to bolt 'anything in place.

The threads the studs are sitting in (motionless) are perfectly capable of withstanding changes
in state (heat and stretching) as the stud is a one time fitting and seats for good, what they do not like
at all, is to have to take the loading lengthwise AND the binding of the bolt thread as they are tightened up.

The thread on the top of a steel stud will be taking this loading of the nuts and I think it is VERY good
practice to do it this way, what can and often does happen when bolts are used is that the threads
in the head will eventually rip out.

It would, in my opinion anyway  be a very good idea to change the bolts for correct length studs as soon as possible.

Very nice job by the way 

Peter 

Might need to copyright this thread, just in case Dellorto or EuroCarbs use it in their installation manual

Hope they work for you

Was thinking the same about the bolts for the manifold. I recall on my old 1800 someone had used a bolt to replace a missing stud on the manifold. That side always leaked fuel under the gasket. I replaced it with a new stud and helicoil as there were damaged threads. Cured the leak and it ran better.

Thanks for the comments guys - Glad you have enjoyed reading this - (Didn`t get to make the phone call today, but will do shortly)

Its always great to get feedback on what is being done here - both good and bad. Its important for newbies reading that do not know me to understand that I am writing this build as I go along, not to show how things should be done, but to hopefully show how and why I did things the way I did, and if that means a monumental cock up then so be it - (I`m on a learning curve too). We all have different approaches to the same problem, some work and some do not, and these build threads, to me are as invaluable as the comments that follow.


@Peter,
As always I bow to your superior engineering knowledge, and will replace those bolts with studs as soon as I get a chance   

Quote@Peter,
As always I bow to your superior engineering knowledge, and will replace those bolts with studs as soon as I get a chance

Heavens  don't be daft, this is expensive stuff thats all, but its best I think to stick to somethings, bolts would be fine
if the heads were not Aluminiumy stuff...

Dave,
Very interested re: your height issues, it's this which has preventing me from committing to Dellortos. Once you are sorted appreciate some measurements re: overallmheight from cylinder face and distance from centre of inlet port to outside of filter housing.
Another great thread.
Paul

@Paul

Centre of ports is guesswork !!

So . . . . .

With tape measure on the top of the rocker cover and measuring upwards

From Rocker Cover to Carburetor base is 105mm  (Using CSP Short Manifold)

From Rocker Cover to Carburetor Top (including linkages) is 220mm

From Rocker Cover to Air Filter Top is 290mm  (Using K&N 63mm Filter)

Hope This helps   

Quote from: Peter on March 14, 2016, 07:12:36 PM

Quote@Peter,
As always I bow to your superior engineering knowledge, and will replace those bolts with studs as soon as I get a chance

Heavens  don't be daft, this is expensive stuff thats all, but its best I think to stick to somethings, bolts would be fine
if the heads were not Aluminiumy stuff...

Peter,

Find me a better expert mate, and I`ll listen to them instead

But until then, if you say studs is best, then studs it is gonna be   


I must admit, the studs were very tight to unwind from the head, and I was not over happy when doing this, so you have highlighted a concern I had when putting this together

Thanks for your efforts. It does. Much appreciated. Looking,forward to see how she runs .
Paul

@Peter,

If looking for a set of studs, what sort of spec should I be searching for?