Aircooled VW South Africa

spacers will move the heads away from the piston, it'll reduce the compression as required, but it;ll kill all performance and lead to a very poor combustion chamber which may detonate easily.

Yes, I don't want to go there. I hope that somebody else could get use out of them, so I'll phone the guy Brian mentioned.

Tony Z wrote: ↑Tue Apr 06, 2021 9:03 am spacers will move the heads away from the piston, it'll reduce the compression as required, but it;ll kill all performance and lead to a very poor combustion chamber which may detonate easily.

I hear what you are saying, but no body will cut a head to if it can not be used.

May not be as easy as implied, but only a part of the concept. I always see a challenge......

Surely there must be a combination of parts to make these heads work, longer barrels, longer con rods, shorter tubes, custom exhaust, custom intakes, and lifters, something ...?

If you know the combination, you may want to keep them or it will enable the next guy to get whats needed to make these heads work.

Thats where I am going with this, Must be a super engine when done, wow... someone will get joy out of it.

OMO

Herman

Those heads have been fly cut to the max approx. 4mm deep and in doing so 1 row of fins has been sacrificed for the top of sleeve not to bottom out, secondly the combustion chamber has been hacked out to get the CR to a more desired level. Those are race heads where everything that goes with them is custom.

retrovan wrote: ↑Tue Apr 06, 2021 2:06 pm

Tony Z wrote: ↑Tue Apr 06, 2021 9:03 am spacers will move the heads away from the piston, it'll reduce the compression as required, but it;ll kill all performance and lead to a very poor combustion chamber which may detonate easily.

I hear what you are saying, but no body will cut a head to if it can not be used.

May not be as easy as implied, but only a part of the concept. I always see a challenge......

Surely there must be a combination of parts to make these heads work, longer barrels, longer con rods, shorter tubes, custom exhaust, custom intakes, and lifters, something ...?

If you know the combination, you may want to keep them or it will enable the next guy to get whats needed to make these heads work.

Thats where I am going with this, Must be a super engine when done, wow... someone will get joy out of it.

OMO

Herman

They can be used, likely very successfully in the application they were made for - Formula Vee
Look at how those chambers are ported.
Those heads would have been cut quite a bit (4mm as Rui says) to increase the compression far more than usable, then ported to unshroud the valves as per the picture and to bring the compression back to a reasonable value, then possibly flycut again to get the compression to where they wanted it.

They might be able to work on the street, but you'll need 100 or 106 octane

Thanks Guys, much appreciated all that info,

Sure some one will benefit by it and now be able to put a label on them for future use.

Thanks Again

Herman

Thanks for all the input, guys. I'll put the heads in storage for now and if anybody needs them, just let me know.

retrovan wrote: ↑Tue Apr 06, 2021 2:06 pm

Tony Z wrote: ↑Tue Apr 06, 2021 9:03 am spacers will move the heads away from the piston, it'll reduce the compression as required, but it;ll kill all performance and lead to a very poor combustion chamber which may detonate easily.

I hear what you are saying, but no body will cut a head to if it can not be used.

May not be as easy as implied, but only a part of the concept. I always see a challenge......

Surely there must be a combination of parts to make these heads work, longer barrels, longer con rods, shorter tubes, custom exhaust, custom intakes, and lifters, something ...?

If you know the combination, you may want to keep them or it will enable the next guy to get whats needed to make these heads work.

Thats where I am going with this, Must be a super engine when done, wow... someone will get joy out of it.

OMO

Herman

I get what you're saying, Herman. I might do the experiment with a spare engine and parts I have lying around. By the looks of it, I need to modify the intake manifold, silencer, pushrod tubes and pushrods. I have some spare 1200 parts which might work. I know the 1200 intake won't work, but I hope the 1200 pushrods might work. Collapsible tubes will take care of the shortened tube length.

73type2 wrote: ↑Tue Apr 06, 2021 8:05 pm ....... I might do the experiment with a spare engine and parts I have lying around. ....

Agree with you, the little bit of work to do those modes will be well worth it

And if you already have the other bits, ....what an exciting project,

I am jealous but filled with excitement for you

Have fun with it.

Herman

Just an update on the heads. The original owner of the heads contacted me and we made a deal. He'll use the heads for Formula Vee, as originally intended. The proceeds of the sale will cover the cost of rebuilding my 1300 twinport heads.

Glad you got sorted, hope it all works out

Another update:

With the proceeds of the Formula Vee heads I could offset the costs of rebuilding my 1300 twin port heads. The heads are now installed and I hope to start the engine tomorrow. Here is a pic of an engine test stand I made by modifying a redundant gym dumbbell stand and some scrap steel. I was also lucky to have an old broken 1200 gearbox bell housing lying around, so I ground in the required areas for fitting the 1300 and installed the bush for using a 12V starter in a 6V housing.



I just need to prep and spray the air filter housing and some other bits tomorrow morning and should turn the key later in the day.

Great result, so happy to see it all worked out in the end and you benefited from the heads.

Nice work with the motor as well as the stand.

Sure she will run just fine.

Herman

Yeah, and just as I was planning a nice aircooled wrenching Sunday, my family changed my plans for me and we’re going for brunch trip. Maybe I’ll still have the afternoon to myself...

I finally got around to turning the key on the test stand yesterday. Cranking to get oil pressure didn’t cause the oil pressure light to go out!! Oil pressure was fine before the engine refresh, but I have removed the oil pump cover plate to sand and spray it. I replaced it without sanding the figure 8 scour marks and added a new gasket. I did some reading and the advice was to sand the plate on a flat surface until it is smooth and install with sealant, no gasket. I sanded for more than an hour and reinstalled with Shellac gasket sealer. I then removed the oil sender and hand cranked to see whether oil flowed out, which it did. I replaced the sender and the oil light went out after a couple of seconds of cranking. Oil pressure problem solved!

Question: I installed honed barrels with new rings. On first startup, what do I do? Do I need to keep the revs high for some time period? Or, can I just install the engine and go drive?

Here’s the fully assembled engine: