I have those aluminium brazing sticks, I repaired my flexplate cover with them, they do work, Although I would not use them in a combustion chamber, the melting temperature of these rods is 389°C and combustion temps can hit 700°C.

I got mine off ebay. Search for HTS2000 brazing rods.

 

so you heated them and used them to build up the plug to turn?

as
Step 2: Heat the work surface (not the brazing rod) until the work surface is hot enough to melt the rod, just as you would if using a solder. DO NOT PUT THE ROD IN THE FLAME. You must bring the temperature of the base metal up to the melting point of the HTS—2000 Fluxless Brazing Rod.


just asking...

 

For the air injection ports I used extruded aluminium rod and turned it to the required diameter.

The HTS2000 rods I used to repair the flex plate cover where one bolt eye had broken off. I built it up and then machined it.

 

could I use a cone cutter.. and cut them (the hole where the air injection empties into the exhaust) then use the HTS2000 rods as per the directions on using them ? then grind them off smooth?

 

Why not cut a thread i to the hole and put in a screw? Say a tapered head or so... Should make it smooth and easy to do...

 

Not in the port, exhaust gas temps hit +700°C and the HTS 2000 melts at 380°C so it could melt. You could use it on the intake manifold end of the hole.


Same again this would need to be on the manifold end of the hole. If I used a steel screw in the port it would make it difficult to blend the bowl because of the hard screw. Plus the steel and aluminium will expand and contract at different rates and there is a possibility the screw could come loose and fall out.

The reason for the plug in the port end is to reduce turbulence caused by the hole.

The aluminium plug has an interference fit and because the aluminium will expand and contract at the same rate it can not fall out.

 

Ah, ok. I'll leave mine as is

 

Air injection hole had disappeared after the port has been cleaned up. I still need to sand the bowl further but I've run out of sand rolls and my mandrel is too short to get in the port so I need to order new ones.

 

Caps

Pic 1 is what you dont want to happen!



sorry they are not too sharp.



And another rescued from my bin for 1 last pic, this one hadn't quite gone but was fractured 3/4 of the way through.



So you want big power then fit decent caps, its not worth a 2nd engine rebuild minimum and junk bottom end if not caught in time.

 

ok, thanks Solutions? in another thread...?

 

Thanks for the photos. Do you make them, or who does, please?
Greg

 

Maybe it was not only the power. Is Not properly balanced crank or rods , pistons? Fault damper?

 

I think I see the stress raiser he was talking about but the picture is not that clear...
an drawing would help

 

Allan Scott in his great book on the TWR ETCC XJS racers, explained that the main bearing caps were always a worry after an hour or two at sustained high revs. Quite frequently they failed or cracked partially during races.
Greg

 

I assume though that that only referred to race cars... I expect the normal caps on the normal, nontuned V12s should withstand a long high rev drive... At least I hope so!

 

Do not worry Daim, half an hour at 5500 revs on the autobahn will be fine!
Greg

 

Only ever seen 1 go on a 'normal' engine. Only ever seen 1 Lister engine without the problem! Had them cracked on a road race car with the TWR pistons and STD capacity, yes it was raced. Just something to consider if upping the power. Removing that ridge is in the TWR (road engine) prep book, as per the engine pics I posted, Group 44 used hardened ali caps but later changed to steel, dont know why. We do a version of these TWR did a steel version, much more sculptured and hence more expensive to produce but I am sure we will do soon, My lad has just put them on CAD in preparation. Had a quick look for the prep book but it doesn't fall to hand, I tell a lie, found it and will post up. Of course you are all utilising the 2 middle water holes in the heads aren't you ? Just thought I would drop that one in there.

 

Here you go.



moves the barrier a little further on but does not remove the need for steel caps on a much uprated V12

 

Oh, I see.... the step was created when they the machined the FLAT spot for the bolt... and they did not see fit to look to see if the process created a concentration of stress...
day to day OK... but when taken where we wish to take it...

so xjr5006 you and your Lad about to make a Run of Caps? and are looking for interested parties....for a pre order

these caps will have to be installed and then a line bore will have to be done correct?

 

ALLOWING MAIN CAPS TO MOVE UNDER HIGH LOAD STRESS WILL EVENTUALLY RESULTS IN CRACKED BLOCKS OR MAIN CAPS
HOLLOW DOWELS that fit into machined recesses,machined around the inner main cap bolts in slight enlarged main bolt cap and block bolt holes with a slight interference fit that extend about 1/4 into each bolt hole, from the main cap /block parting line, tend to significantly reduce main cap movement

anyone seen that done for our main caps?
the more I learn, the more I really wonder how I put that 1275 together and how I did not Kill myself spinning it to un-godly rpms....