TheSamba.com :: View topic

Sun Mar 09, 2014 12:11 pm

Hi there, :shock:

I´m willing to rebuild my 1300 dual port type I engine. Is my first build and I have many doubts.

I wanna to asked you guys about cylinder heads, since I´ve read different information on different sites. Probably someone allready went through it.

My case is a As 41 AB, stock. And I don´t wan´t to work on it so, I wan´t just to upgrade to 1600, dual carburetor, and just maybe change the camshaft for a more agressive one.

My first doubt´s come about what kit or pistons and barrels will fit my case and head just as they are.

Thanks! 8)

Sun Mar 09, 2014 4:30 pm

The head should be 90mm, not 89
90mm at the head fits 77mm cylinders, AKA 1200 and 1300cc engines.

Sun Mar 09, 2014 10:22 pm

modok wrote: The head should be 90mm, not 89
90mm at the head fits 77mm cylinders, AKA 1200 and 1300cc engines.

is just the tool I used.

So I think I can fit anyn1600, 1641, and 1700 slip on kit. I,m I right?

:?:

Sun Mar 09, 2014 10:38 pm

1300cc top of cylinder is 89.8mm
1500cc and 1600cc top of cylinder is 93.8mm
This is from Cima/Mahle tech sheet.
Opening in heads will need to be a little bigger so cylinder can expand and does not seize in head.

Sun Mar 09, 2014 10:44 pm

you can fit those piston its in your case, but will not fit with those heads.

Mon Mar 10, 2014 3:09 am

Jroggen wrote: modok wrote: The head should be 90mm, not 89
90mm at the head fits 77mm cylinders, AKA 1200 and 1300cc engines.

is just the tool I used.

So I think I can fit anyn1600, 1641, and 1700 slip on kit. I,m I right?

:?:

yes it is possible, the heads will need to be bored out to larger diameter.

The thickness of the cylinder should be at least 3.5mm, so with 90mm bore in head the largest size possible is 83mm (90-7=83)

83mm cylinders that fit your heads are not sold, but they could be made.

EDIT: 83mm cylinder kit to fit 1300cc engine was made at one time,
cima kit c70-ex

Mon Mar 10, 2014 3:41 am

modok wrote: Jroggen wrote: modok wrote: The head should be 90mm, not 89
90mm at the head fits 77mm cylinders, AKA 1200 and 1300cc engines.

is just the tool I used.

So I think I can fit anyn1600, 1641, and 1700 slip on kit. I,m I right?

:?:

yes it is possible, the heads will need to be bored out to larger diameter.

The thickness of the cylinder should be at least 3.5mm, so with 90mm bore in head the largest size possible is 83mm (90-7=83)

83mm cylinders that fit your heads are not sold, but they could be made.

EDIT: 83mm cylinder kit to fit 1300cc engine was made at one time,
cima kit c70-ex

This is what I read about this somwhere else:

At aircooled.net it says no but on Rob and Dave´s (http://www.vw-resource.com/engine_rebuild.html) they say yes, and you get some more compression.

This is what Rob and Dave´s say:

You can use the 1300 cylinder heads, but there are two problems.

1.The valve sizes are a little small, which will restrict breathing for a 1600cc.

2.The compression ratio will jump to about 8.8:1, since you are squeezing more cylinder volume into the same head space. This needs about 98 RON octane (about 95AKI in the USA) to stop detonation.

I really don´t like the idea of spending money on new heads. :roll:

Mon Mar 10, 2014 5:13 am

IIRC, 1300 dual port heads have the same valve sizes as 1600, 35.5 x 32. The issue is the shrouding, due to the small bore.

Mon Mar 10, 2014 8:03 am

in this day and age dual port 1300 heads tend to be cracked, so you probably have to invest in new heads anyway

but yes, you need to bore out the heads to use 1600 cylinders

Mon Mar 10, 2014 11:43 am

FreeBug wrote: IIRC, 1300 dual port heads have the same valve sizes as 1600, 35.5 x 32. The issue is the shrouding, due to the small bore.

Yes, that's the valve size on those heads.

Buying new heads is a pain. But at this point I don't want to bore this or that. So I have to search bigger heads the biggest cylinder kit, but with out boring the case.

Let's see what's in the market.

Thanks guys youre if great help :wink: