Author Topic: Head porting on a SP 1600  (Read 5872 times)

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Offline scratchyratchy

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Head porting on a SP 1600
« on: August 20, 2010, 12:10:49 AM »
Will porting (intake, exhaust, 3 angle valve) on a SP 1600 heads give me some increase in HP?  Is it worth it or not?  and will this work with the stock jugs and pistons?  or do i have to build on that too?

Offline slammed66

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Re: Head porting on a SP 1600
« Reply #1 on: August 20, 2010, 07:00:04 PM »
Porting and polishing a sp 1600 is not going to make any difference what so ever. Probably wouldn't hurt to clear out some of the casting flaws and unshroud around your valve guides but a sp will never create the demand for air where porting makes a difference.

Making sure that the castings on the heads where the manifolds go are not bigger than the crush gasket. Gasket matching at the carb manifold and head will be your best bet.

A good valve job will always be nice especially if the heads are well used.

So short answer is on a 50 horsepower engine you will not feel the 2 horsepower difference. 

Offline scratchyratchy

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Re: Head porting on a SP 1600
« Reply #2 on: August 20, 2010, 09:43:40 PM »
Hmmm...  Will this be the same for DP's? 

Then what's my best bet on putting some HP on a SP?  I was thinking of just doing some of the basic bolt-ons and this is what I was going to do in the long run with the SP 1600....

-1.25 rockers w/ chromoly push rods
-110 cam
-87mm piston/ cylinder kit (1641)

I think that's about it?  how about the crank?  would i have to some boring on the case?

Offline slammed66

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Re: Head porting on a SP 1600
« Reply #3 on: August 30, 2010, 11:00:46 AM »
Porting will make much more difference on a dp engine. In essence you have twice the air flow area of the sp. Still only as good as the whole combo. Gasket and manifold matching, and de shrouding the valves/valve guides is the only thing that will do anything unroll you step up to bigger valves and bigger engine size, then porting really makes a difference.

Ratio rockers is like putting a bigger cam in without splitting the case.
So if I were doing these in some kind of order.
1 ratio rockers
2 heads refreshed, valve jobs, prt matching and light casting and deshrouding
3 1641 fresh pistons and cylinders (with the refreshed heads) and slightly more cc
4 then comes splitting the case to build something else, go with at least 1776, the 110 is a proven cam. And this will work with the dual singles or a 34 pict until you upgrade carbs ( I would go dual port when doing anything over a 1641

Offline scratchyratchy

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Re: Head porting on a SP 1600
« Reply #4 on: August 30, 2010, 11:35:27 PM »
thanks for the info slammed...

Offline slammed66

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Re: Head porting on a SP 1600
« Reply #5 on: August 31, 2010, 12:43:38 PM »
Make sure if you are putting a cam in eventually to get valve springs as well as upgraded pushrods

Offline scratchyratchy

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Re: Head porting on a SP 1600
« Reply #6 on: September 02, 2010, 10:32:00 PM »
Nah, i think of just getting the 1.25 rockers and push rods...  going to save $$$$$$ on a bigger engine

Offline LUFTVOLKS

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Re: Head porting on a SP 1600
« Reply #7 on: September 04, 2010, 05:53:29 PM »
I thought I put a post but its gone now.

This guy is doing the same and his heads look GREAT!!

http://www.thesamba.com/vw/forum/viewtopic.php?t=343974

he would get more power and MPG with a regular empi/bugpack header. SP heads are less likely to crack and give pretty good performance with some work. I think the secret is the 37mm intake valve along with the D shape port. Once you understand what is going on with performance on an aircooled engine you can then apply what you learned on your next BIG build. Have anything in mind for the bigger one yet?

Offline LUFTVOLKS

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