TS head to old block

Mike Valant's web site has a piece on a TS head fitted to a stock spider block, the pros are obvious, much easier and less expesive to ship from Europe, could actually have the head shipped to your house as opposed to picking up a crated motor at the port, not to mention the stronger internals of the spider block, but it's not done that much. SO, what are the cons? and what modifications to the spider block are neccessary?

[JoeCab]

It takes quite a bit of machine work to do it. I don't think the stud pattern is the same, to begin with.

I think when you figure out costs, you would be way behind. The late Twin Sparks are robust and reliable, and I haven't heard about many head gasket issues.

Gary Valant did this conversion, IIRC, to fit the rules of some racing class. And, quite frankly, not many of us operate at Gary's level, which is why I don't think others have pulled it off.

Joe

Thanks Joe, well you know what they say, if it sounds to good to be true-, at least for the average Alfa mechanic.

[ossodiseppia]

The stud pattern is the same, but you eill need longer ones as the twin spark head is much taller than the 105/115 head.

I was fortunate enough to be around Gary when he was building the GTV and the twin spark. The car was amazing. When he started the engine, it would make the hair on the back of you neck stand up.

Mike has sold everything Alfa that he owns. I don't think he wants to be involved in Alfas anymore. So, he would not be a resource if you were to attempt this.

I do believe that Peter Webb is a member of the BB. He has the other twin spark that Gary built.

[patpend2000]

To make a modern TS head fit on a standard 2.0L block you need to machine pockets in the head as the studs on the bosch/spica motors are shorter than the TS studs, the spacing is the same. You can also source new nuts from Jim Steck as he has done this conversion and has made special nuts for this process.

In addition to the head you will also need the following parts as they are TS specific:

Rods
Pistons
Cam Cover
Crank Pulley, and timing sensor.
Intake manifold


Kelly

[PSk]

Quote:

Originally Posted by patpend2000 To make a modern TS head fit on a standard 2.0L block you need to machine pockets in the head as the studs on the bosch/spica motors are shorter than the TS studs, the spacing is the same.

[P.Webb]

I do indeed have the other Valant motor. What would you like to know about it?

The head is countersunk to fit on the 2L block and studs. As Kelly said, there are special nuts to make it all work.

There are other considerations to doing it this way. You'll have to figure out ignition. You'll need custom flat top pistons to work with the TS head. The stock TS pistons yeild to low of a CR and the 2L piston domes are too high for the TS combustion chamber.

Other people may have figured out something clever for these issues since Gary did my motor.

-Peter

[PSk]

Quote:

Originally Posted by P.Webb The stock TS pistons yeild to low of a CR ...

[P.Webb]

Quote:

Originally Posted by PSk Machine some off the top of the block!. That is the beauty of this open block design and studs going right down to past the crank ... you can machine off just about whatever you want! If the TS pistons work with the TS head, and in the normal block yeild too lower CR and in the TS block yeild the right CR, then the height (crank centre to top of block) of the TS block MUST be shorter than the normal block (all else being the same, ie. crank and using TS rods and TS pistons). This is not rocket science guys ... . Now if you are going to make a race engine ... you will want your own pistons anyway. Pete ps: If you are going to do this job, you need access to some machining equipment ... it is not just a bolt on job. I guess counter boring the head and supplying special nuts and special pistons is an attempt to make the TS head a simple bolt on job ... ie. you do not have to touch the bottom end (other than installing new pistons). Personally I'd just chuck the block and liners in a milling machine ... and use the TS pistons. Sounds like we are only talking millimetres, and you probably should face the block/liners to check straight anyway.

[PSk]

Quote:

Originally Posted by P.Webb I don't believe anything you suggest above could really work. Do you have any examples of running engines? -Peter

[PSk]

Here is how I think of a motor when building something special

You sit down and work out what you want from this motor, ie. club race, street, full race screamering nutter, etc.

Once you have decided on that you sit down and work out:

• Compression ratios.
• Fueling methods (carb sizes, etc.).
• Cam profiles.
• Head/valve airflow requirements, and thus valve sizes, etc.
• Exhausting methods (4 into 2 into 1 or 4 into 1, etc. ... and sizes, plus noice laws, etc.).

You then need to work out how to obtain all these things.

Compression ratio is determined by the volume that the piston and head leave when the piston is at top dead centre VERSUS the volume when the piston is at bottom dead centre.

Moving the crank closer (thus piston) to the valves (either by machine the head face OR block/liners top) will increase the compression ratio. So will adding metal to the combustion chamber OR piston top (but this makes the piston heavier theoretically [specially made ones may well indeed end up lighter than a standard TS piston ... but a specially made piston that is SHORTER will be lighter again]).

Anyway the most important thing is to work out the relationship measurement wise between the valves, combustion chamber and piston and then work backwards to modify everything (if necessary) to make that happen. In the end what happens in the combustion chamber makes the HP ... and the combustion chamber does not care how you do it, as long as it remains stable .

Luckily Alfa Romeo did not change the bore centres and head stud positions ... thus we have the raw tools, how it is all put together will depend on what we individually think works best ... and there is more than one right answer.

EDIT: Here is a picture of a normal block showing the top quite well:

Image obtained from www.mikevaliant.com

I believe you could machine around 3mm off that block/liners/front cover with out upsetting anything.

If you study how far the water pump is down (around 20-25mm) you could effectively machine right down to there ... but then you would have to modify the front cover and you might have head gasket issues as you will have machined away the gasket face on the block. BUT structurally the block would be fine.

Pete

[patpend2000]

This is why you need to use the TS rods, they are longer than standard 2.0L rods, FYI the 155 rods are even longer. You could use them to regain compression.

Kelly

[PSk]

Quote:

Originally Posted by patpend2000 This is why you need to use the TS rods, they are longer than standard 2.0L rods, FYI the 155 rods are even longer. You could use them to regain compression. Kelly

[sono veL.O.ce]

isn't there a problem with using longer/shorer rods and/or milling the block in that you need custom pistons? don't these methods end up changing the "squish-volume" band of the combustion chamber which could lead to severe detonation even at low compression ratios? I second that when making these mods becareful of what goes on in the combustion chamber.

custom pistons like gary used could solve this problem, but I don't think it should be ignored.

[BigSwede]

You guys need to settle down... First of all the TS rods are 1mm shorter then the regular Nord rods so just slapping on the TS head and pistons would mean that you wil not be able to turn the engine over, trust me, I did extensive hands on investigations last winter.

Milling the block and liners sounds like a good way to get all kinds of headgasket problems IMO.