The title of this thread may sound like a bit of an oxymoron, however I need to ask the question as I can't afford new heads and can't see the point changing to dual port before I have the dosh to get a proper motor. what I want is a stop gap measure that can be built upon slowly in the future.

At the moment I have a 1300 SP, with a Pobjoy sump and Extractors from VVDS.

I'm going to be getting a set of 34ICT single ports to go on, considered going with SU carbs but i'm not talented enough if they arn't in kit form (if you have info on SU's in VWs please send me some pictures and info...)

So what I want to know is, what can be done to a single port head to improve breathing a bit, and what mods are best to do to make it go a little bit better.

I thought I would get the motor rebuilt with a C/W crank, lightened flywheel, hotter cam, and bore it out to 94mm with the view to using all these items in the future.

I know that a 1916 won't breath that well with S/P and the exhaust and carbs that I have, but it should give a bit more squirt than stock.

Please offer me your opinion, I know dual port is the way to go (despite what this thread suggests..) but to change will cost more than I want to spend on tinware, exhaust, carbs etc...

Cheers

Shaun

On the bright side the sp will have more low down torque due to air velocity with less cross sectional area

You can buy reconditioned heads..
or get 2nd hand ones...

You don't really need a counterbalanced crankshaft..

ratio rockers will open the valves up for You..

but a big engine with single port heads doesn't make any sense to Me..

an 1835 with twin carbs and lightened flywheel is all You really need in My Humble opinion... IMHO...

You already have the exhaust...

two reconditioned dual port heads..

LEE

As Lee says, if you can afford a counterbalanced crank and 94s then you can afford twin-port heads. The cost of converting from single port to twin will be less than the cost of the bore kit, and it opens up a much wider range of more common performance carburettor kits. There's just no logic in keeping the single-port heads if you're going to build a big motor. The exhaust is the same for single or twin port, tinware costs bugger-all (I scrounged mine for free) and I would suggest that you could probably get a decent pair of used twin-port heads for about $200 or even less, manifolds are included in a carb conversion kit or until you can afford some nice carbs, a stock intake manifold and carb should be cheap as well. Making a custom manifold to fit decent carbs onto a single port will cost more than the twin port conversion.

Sounds like an interesting project!
In the 1970s, Dyno Don in the USA ra low 15seconds in his street noth with single ports.
http://www.dynodon.net/ 

Interesting post Shaun... makes me wonder if I told you at Valla about what I was planning for my ghia ???



My plan is for an engine that EXTERNALLY looks like a 40hp 1200... possibly with a Judson or 60's twin carb kit to get that Vintage Speed look... but internally had all the good bits in it, 94s, decent cam etc. The idea to have an engine bay that looks period, but with grunt and reliability enough to be a comfortable cruise car and still eat most modern cars if I want... but without any of the race car looks or hassles. Ghia's have always reminded me of 60's Aston Martin's... so I really want a Ghia that goes like an Aston.

So doing basically the same to have an upgrade path... well yeah - if planned out fully I'd think starting with the bottom end, and then doing the top when funds allow should give you some extra smiles no worries.

That's also interesting Sides....makes me wonder if I told you about what I DID in 1961 to my BRAND NEW 40HP Beetle????

As my car was still under warranty, I couldn't let on what Jack Bono (the Dave Butler of the day) did to my engine.

The barrels were bored to 80mm, Ford pistons fitted, cam ground to 356 Super grind, balanced, 32mm inlets, big ports, 9:1 comp. etc. The exterior was left stock!

At the time, I worked for a VW dealer, and it was difficult to keep a straight face when I went to pick up the Beetle after its first service. Nev. Martinson, the service manager was adjusting the idle screw when I arrived, and was complaining about not being able to 'get a nice idle'. He said it went VERY well on the road, but the idle was a bit rough. I told him not to worry about it - it would probably settle in within a few miles. Nev. found out later what we had done, and never forgave me

Don't be like me Shaun - you know, stubbornly staying with link pins, swing-axles, drums, skinny wheels, etc. - twin ports make sense!

Cheers, Greg

That's very cool Greg !!! My plan really came from my Dad... he's similar vintage to yourself and was involved in /knew of some of the same sorts of stunts back in the day.

Actually I remember reading somewhere of a story with Gene Berg... he'd opened up the passages in the carb I think it was on his new beetle to give it a bit more go, and when the dealer sussed what had been done they went and offered him a job !!!



But yeah Shaun - twin ports will definitely be better for performance overall... I'm doing it just for the looks, and well just the plan trickery of it all...

Not entirely like you Greg - Skinnys - yes ,Link Pins - yes, Swing axle - Yes but i'm going to discs with 4x130 pattern.

Twin Ports do make sense, but owning and racing a VW doesn't in alot of ways... I'm jsut imagining the low-end torque that the SP would have in 1916 Twin Plugged guise.

(Stupidly I think i'm really starting to like the sound of a SP 1916.... why do I do this to myself)

Cheers

Shaun

Greg great Video on that DVD, some powerful cars ran in that series but you were up with them, shame you go caught by the car spinning in front...

Extract from Dyno Don's Website

"It was 1972. I was bummed and looking for more power, after narrowly missing a second place finish at the Bug-In with my '63 sedan.

I drove to Fullerton to see my friend, Randy Jones of the Superbug shop, and outlined my upgrade plans. Randy hand ported the single port heads with his trusty Dremel tool, installed an Engle 100 cam, balanced & blueprinted everything he could, then put the 1600cc motor back together. The motor sang from 800 to 5500 RPMs in a blink, with just a touch of the throttle. I was pleased, to say the least!

My buddy Dennis Hardesty and I took the new and improved 1600 out for it's maiden voyage. We'd been driving for about twenty minutes, and decided to pull over to cool down at the doughnut shop at Magnolia and Orangethorpe, in Fullerton. All of a sudden, we heard the bellowing sound of IDA's, coming from across the street.

Dennis and I looked at each other and said, 'Why not??' We packed up our late night snack, got into my car, and went out after an early VW sedan that now waiting at the stop light. We wanted to see what the Dyno machine could do against a raging, Weber powered car. We pulled up next to a cool early looker, and gave the driver and passenger the 'You want to run it?' look.

The light turned green and I was off like a rocket, not even looking over at the other car, as I banged second and third gears. We got up to about 75 mph and began to run out of power (stock 30 PICT1 carb). I finally looked back to find that we had waxed the 48 powered VW, but could hear the ferocious sound of the IDA's and the motor pulling like a freight train. I decided to back off the throttle, happy with the performance of my engine.

The other car was next to us in a millisecond, with the passenger hanging out of his window, waving us over. As we pulled off to the side of the road, the passenger of the other car got out first. This guy was HUGE; about six feet tall and 265 pounds, with a look like he was going to tear both of our heads off. The smaller driver got out and walked up to my car, behind his big friend.

We both acknowledged the cool race. Having said that, I couldn't resist the temptation to ask him, 'So, what are you runnin?' We walked to his car and he opened the deck lid to show us what we had suspected - a pair of 48 IDA's sitting in the engine bay. The driver then told me it was an 1835 with an Engle 140 cam and big valve heads. Upon hearing this, my friend Dennis looked at me with the most sheepish grin, knowing what was to take place next.

The passenger then asked me what I was running and I replied, 'Just a stock 1600!!'. Both of the other guys went nuts and said, 'No way! Lets look at your engine." I cheerfully obliged, opened my decklid, and watched their jaws drop to the pavement in total disbelief. I showed them that indeed, they had just been waxed by a stock looking, single port engine.

Upon saying our goodbyes, I realized that I had just blown the doors off of Mark Rosevear, who was the son of the owner of the famous Auto Haus company. I later went on to work at Auto Haus, as a result of our chance meeting..."

Quote:

Originally posted by Sides I'm doing it just for the looks, and well just the plan trickery of it all...

excellent story

LEE

an easy upgrade is a pair of kads with single port manifolds. extra torque and breaths well! $650 give it a go!

Wiseoldub, where have you seen some single port kads for sale?

I havn't been able to find much on here about them,

Quote:

Originally posted by HappyDaze Clever move Sides - keep it a secret, now nobody will know what you've done!

POWER!!!.....

http://www.shop.kaddieshack.com/TURN-KEY-Kaddie-Shack-SVDA-modified-Rebuilt-R...

single port Kad kits, good thing is that I can use the kads on a bigger engine!

http://educatedstupid.com/media/ars/clarkson-power.jpg 

(apologies for the above, slow day at work....:td