Bay Area VW Club

blown luv · VW Junkie Joined: 02 May 2008 Posts: 150

thinking about freshing up my 1600 sp.Was thinking bout 90.5 pistons and cylinders. Would the stock heads be any good for this combo ? What if I port and polish them? Also on a sp what are my carb choices,can I run dual carbs on a sp? What cam would be a good choice? Plan on running a header with mondo muffler.

bavwcjoel · Posted: Fri Jun 05, 2009 10:34 pm Post subject:

first off if you get your case bored out for a 90.5mm piston you'll have to have your heads bored out as well. the only piston and cylinders that will slide into the stock case cut outs are either the 85.5 or 87-88mm without having to machine the case and heads.

now, if you currently have single port heads i would personally ditch them for dual port heads, and you can find new heads pretty cheap such as the 044 CB performance heads or 043 mexican heads that have already been cut for larger pistons.

single port heads flow ok for a stock motor but now you're trying to cram more air through there and the single port really restricts and limits the airflow, UNLESS you turbo it. I've heard about turbo single ports which were torque monsters but still why go through the trouble when you can get better designed flowing heads of a dual port? also, personally i would go with a new head perferably CB performance 044 with larger valves.

carburetor is totally up too you. you can go with either a center mounted double barrel carb, or a dual carb set up with either single or double barrel carbs. such as either the kadron set up of dual solexs or webers. and the carb set up really depends on the cams and what you're trying to achieve.

Now, may I offer some food for thought? Ok, for what you would be spending on upgrading to 90.5mm pistons and cylinders you should consider just going to 94mm piston and cylinders. the cylinder walls of the 94mm pistons are actually thicker than that of the cylinder wall of the 90.5mm piston which would overall allow the motor to run cooler. instead of going to a 1776cc motor you would now be in the range of a 1914cc motor. if you're planning on getting a crank i would also suggest either considering getting a 74mm or 76mm stroke crank since they really aren't that much more than if you were to buy a new 69mm crank. a 94mmx74mm will put you in the 2054cc motor range. and the 94mmx76mm would give you a 2110cc motor and would pretty much run as a stock motor you wouldn't have to clearance the inside of the case for your crank either.

remember these are just options that most people are not aware of.
_________________
Joel

2008 Rabbit
1974 Beetle
1971 "Choptop" Beetle
1973 Squareback/Variant
1979 Coleman Camper (Bus)
1971 TITLE!!! WOOT WOOT!!! the car is a rust bucket but i got a piece of paper for it!! Smile

veedubcrazy · Posted: Fri Jun 05, 2009 11:56 pm Post subject:

VW performance is a slippery slope, my friend... Once you start sliding down it, look out... 8)
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Now, it's a 2387!!!
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blown luv · VW Junkie Joined: 02 May 2008 Posts: 150

Ok joel,what I wanna do is build more power with less money.Was thinking 1776 because I could use the stock crank.Not building an all out drag motor,just a a good driver.As for veedub,I have a diease ....I want to hop up everything I buy....lol Thanks for the help guys

KIDSPEED · Joined: 14 Jul 2009 Posts: 3

Ok third time trying to post this. 94s are not thicker wall than 90.5s. Go research. Information on wall thickness is out there. 94s are thicker than old style 92s which is why lots of people now build 1914s but hardly anyone builds 1835s anymore. 90.5s considered by many to be as good as stock. If you do go to dual ports I would avoid mexican heads that have smaller (some do) valves than old stock heads. One more thing, 74mm crank 9 times out of 10 will drop in to stock case without clearancing but you still need to use clearanced( i.e. stroker rods) 76mm sometimes will go in with just clearanced rods, sometimes not. Just depends. The clearancing is usually minimal however. Went in to a lot more detail twice before only to realise my post would not go through when done so I say build even a 1641 (slip in 87mm) 1776 or 1914 with Engle 100 or 110 cam twin single barrel carbs and stock d/p heads (since budget is concern) or use the single ports if they are in excellent shape but they will limit top end horsepower. Either way will have more HP & feel like considerably more torque & still get decent MPG to boot.

veedubcrazy · Posted: Mon Sep 14, 2009 10:49 pm Post subject:

^^^^ Good points... A well balanced, built 1776 is hard to beat. Both in budget and performance...

Never rode in a VW with a SP 1776 though...
_________________
Now, it's a 2387!!!
C'mon, I dare ya!!!

blown luv · VW Junkie Joined: 02 May 2008 Posts: 150

Are you saying I van run dp heads on a sp block? If so WOOHOO I see a 1914 in my future!

veedubcrazy · Posted: Mon Sep 14, 2009 11:52 pm Post subject:

Yes you can. Just change out the cylinder head studs and upper cooling tin. Bam, there ya go...
_________________
Now, it's a 2387!!!
C'mon, I dare ya!!!

blown luv · VW Junkie Joined: 02 May 2008 Posts: 150

whats the difference with the studs?

veedubcrazy · Posted: Tue Sep 15, 2009 1:16 am Post subject:

The lengths...
_________________
Now, it's a 2387!!!
C'mon, I dare ya!!!

gixxer 711 · VW Junkie Joined: 01 Oct 2007 Posts: 134

veedubcrazy · Posted: Tue Sep 15, 2009 7:37 pm Post subject:

That, and the possible deep stud behind #3.
_________________
Now, it's a 2387!!!
C'mon, I dare ya!!!

thingmon · KDF'er Joined: 19 Dec 2005 Posts: 824 Location: Clear Lake

Quit messing around and put a Caddy Northstar V8 in it. Geez. You know you want to.
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Dave T.

blown luv · VW Junkie Joined: 02 May 2008 Posts: 150

at least a twin turbo small block chevy.......

bavwcjoel · Posted: Fri Sep 18, 2009 2:51 pm Post subject: