I just got a 55 speedster replica. Would like to know how to boost hp but keep reliability. The car has kadron carbs and it's a 1600 and thats all I know. I see skat has a complete hp kit are they any good? Knew to this. Thanks Al
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I just got a 55 speedster replica. Would like to know how to boost hp but keep reliability. The car has kadron carbs and it's a 1600 and thats all I know. I see skat has a complete hp kit are they any good? Knew to this. Thanks Al
A 1600, huh? You want to boost horsepower reliably? That shouldn't be too hard. Call a reputable builder (ACE, CB, etc.), and get out your check-book. 100 reliable horsepower should be available for roughly $2K-- after that, it costs about $100 per h/p.
There's no replacement for displacement.
There's no replacement for displacement.
Well said Stan.....Theres no replacement for displacement! Just go big...Size does matter! You'll be glad you did!
Al; if you want to keep your displacement you'll go a long way by porting your existing heads and installing ratio rockers (you can go up to 1.4 to 1 safely provided you have the stock cam). Install some nice heavy duty springs also. Also get yourself a nice exhaust system (if you don't already have one) and you'll start seeing some dramatic changes in your power band.
With a stock 1600 cc engine and a stock cam, the installation of heavy duty springs is over kill. Install springs that will keep the valves from floating, not just rob horse power as the cam tries to open the valves. It also puts undue wear on the valve train and in some circumstances can cause a push rod to bend. If you're going to install 1.4 ration rockers, make sure the geometry is correct as you don't want the rockers wobbling or pushing the valves under friction resistance. If you do this, you'll also want to install solid rocker shafts and get rid of the wave washers and spring retainers.
Porting and polishing the heads will make a significant difference and the best thing you can do is to get rid of the Kadron's and buy a pair of small venturi Webers (32 or 34) If you do purchase a set of carb's then you'll have to jet them properly to make the engine run smoothly. While you're at it, have the intake manifolds ported and matched to the head intake ports.
An exhaust system in most cases makes more noise than horsepower but it does allow the engine to scavenge exhaust gasses more completely provided it's an equal length system.
Additionally, 87 mm pistons and cylinders can be installed without cutting your case. This will bring the displacement up to 1641 cc's from your current 1585 cc's (A stock 1600cc VW with 85.5 mm pistons and a 69 mm stroke crankshaft is actually 1585cc's.)
If your plan is to stroke the engine and add larger pistons then extra cooling is desired. If the engine has a dog house cooler than that's a good start. Most large bore and stroke engines need extra cooling via an external oil cooler with a fan. You still run the risk of having the heads run too hot but that can be monitored via a cylinder head temperature gauge.
As soon as you start tinkering with the stock engine, the dominoes start falling. In other words, if you do this, then you have to do that etc
Porting and polishing the heads will make a significant difference and the best thing you can do is to get rid of the Kadron's and buy a pair of small venturi Webers (32 or 34) If you do purchase a set of carb's then you'll have to jet them properly to make the engine run smoothly. While you're at it, have the intake manifolds ported and matched to the head intake ports.
An exhaust system in most cases makes more noise than horsepower but it does allow the engine to scavenge exhaust gasses more completely provided it's an equal length system.
Additionally, 87 mm pistons and cylinders can be installed without cutting your case. This will bring the displacement up to 1641 cc's from your current 1585 cc's (A stock 1600cc VW with 85.5 mm pistons and a 69 mm stroke crankshaft is actually 1585cc's.)
If your plan is to stroke the engine and add larger pistons then extra cooling is desired. If the engine has a dog house cooler than that's a good start. Most large bore and stroke engines need extra cooling via an external oil cooler with a fan. You still run the risk of having the heads run too hot but that can be monitored via a cylinder head temperature gauge.
As soon as you start tinkering with the stock engine, the dominoes start falling. In other words, if you do this, then you have to do that etc
Actually ratio rockers are easier on the valve train (less guide wear) and are less noisy; obviously provided the geometry is set correctly. As per Gene Berg's literature the benefits of using heavy duty springs far outweigh the minute amount of extra horsepower they'll need as they'll prevent valve float(which is disastrous for the engine) when revving the engine more. The rigid rocker shafts are definitely a must as well as chromoly pushrods or heavy duty aluminum pushrods (available from Aircooled.net) and swivel feet (or elephant feet) valve adjusters to finish bulletproofing your valve train. Kadrons are ok and will work good if adjusted right but if you want more adjustability (and have more disposable income) you can go to dual throat Weber or Dellortos for even more increased performance.
bigger carbs for the sake of bigger carbs doesn't increase hp unless
the engine is under carbed to begin with. The ability to adjust/tune
your a/fuel mix through the full rpm range will icrease drivability.
the engine is under carbed to begin with. The ability to adjust/tune
your a/fuel mix through the full rpm range will icrease drivability.
So from above you have alot of options depending on how deep your pockets are and how much added HP you desire. Any mods to a worn engine are a waste of $. Options then include some wrenching without removing the engine (rockers, exhaust, better ignition); pulling engine for heads and PC; and, finally, spliting case for bore/stroke and new agressive cam. Remember HP produces heat so adding deep sump or external cooler increases any engine's longevity - so a good mod to do up front.
Many folks like to add chrome cooling time when they soup up an engine --- wrong! It produces NO HP and actually is a deterrent to cooling. Complete/stock OEM tin in good shape is best way to go. Clean it up and repray with heat resistant paint or if your have spare $ have it powder coated.
Many folks like to add chrome cooling time when they soup up an engine --- wrong! It produces NO HP and actually is a deterrent to cooling. Complete/stock OEM tin in good shape is best way to go. Clean it up and repray with heat resistant paint or if your have spare $ have it powder coated.
Ricardo,
Unfortunately, Gene Berg is dead and over the past 20 years, many of his idea's have been proven to be old technology.
Back in the late 70's and early 80's when I was building high performance VW engines, I knew Gene Berg fairly well. I respected his opinions but regardless of what I did to show him that there was a "better way" or "another way" he argued that he was correct and everyone else was wrong.
Modern engine builders no longer just install Heavy duty valve springs. Through experimntation, they determine what spring rate is needed to keep the valves from floating and that's what they install.
Heavy duty for the sake of heavy duty is old school thinking or, the easy way out.
Unfortunately, Gene Berg is dead and over the past 20 years, many of his idea's have been proven to be old technology.
Back in the late 70's and early 80's when I was building high performance VW engines, I knew Gene Berg fairly well. I respected his opinions but regardless of what I did to show him that there was a "better way" or "another way" he argued that he was correct and everyone else was wrong.
Modern engine builders no longer just install Heavy duty valve springs. Through experimntation, they determine what spring rate is needed to keep the valves from floating and that's what they install.
Heavy duty for the sake of heavy duty is old school thinking or, the easy way out.
Al, Drive and enjoy what you have. If you decide to keep it then upgrade at a later time when you have a little more knowledge under your belt. For information take a look at "shoptalkforums.com"
and learn from other peoples experiences. Lottsa info there.
and learn from other peoples experiences. Lottsa info there.
" . . . respected his opinions but regardless of what I did to show him that there was a "better way" or "another way" he argued that he was correct and everyone else was wrong."
Whew, for a moment there, I thought that you were talkin' about Raby . . .
Whew, for a moment there, I thought that you were talkin' about Raby . . .
Al, I upgraded my 1600 to 1680 by installing larger jugs and pistons and then installed 40m twin dual webber carbruators. The difference was amazing, my Spyder would lay rubber on take off and attracted speed tickets as well as a great deal of attention. I dropped that engine and tried a 2110 but the increased noise level outweighted the increase of acceleration so I switched back to the 1680 with Zoom tube exhausts. The tube style exhausts produce a beautiful drone at cruising speed and only roared under heavey acceleration.
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I had this saved from George Brown as it makes a heck of a lot of sense in juicing up a 1600cc motor....Alan
_____________________________________________________________________
Subject: Re: engine build
From: "George Brown ********.COM)"
Date: Fri, 18 Jan 2002 11:08:36 -0500
_____________________________________________________________________
John is right, spend the money on getting your ports cleaned up and go
with the stock valves. You'll probably also want to use single
coil performance springs as insurance. I would also suggest
increasing the compression ratio slightly, say to 8.0 to 1. Have
crank/flywheel/pressure plate balanced as a unit, and balance rods and
piston assemblies. Use new lifters and make sure they're properly
radiused and hardened.
Lightening the flywheel would also be nice, but on smaller engines
this may not be worth the effort.
Add a decent 1 1/2" merged exhaust system, Petronix (or Compufire)
magnetic trigger to the distributor, use a Bosch "blue" coil, jet the
carbs properly, and you should be good to go.
_____________________________________________________________________
Subject: Re: engine build
From: "George Brown ********.COM)"
Date: Fri, 18 Jan 2002 11:08:36 -0500
_____________________________________________________________________
John is right, spend the money on getting your ports cleaned up and go
with the stock valves. You'll probably also want to use single
coil performance springs as insurance. I would also suggest
increasing the compression ratio slightly, say to 8.0 to 1. Have
crank/flywheel/pressure plate balanced as a unit, and balance rods and
piston assemblies. Use new lifters and make sure they're properly
radiused and hardened.
Lightening the flywheel would also be nice, but on smaller engines
this may not be worth the effort.
Add a decent 1 1/2" merged exhaust system, Petronix (or Compufire)
magnetic trigger to the distributor, use a Bosch "blue" coil, jet the
carbs properly, and you should be good to go.
Sorry but I think most of Gene Berg's tricks of the trade still apply today. I know that some of them have been proven not as set in stone with empirical data by people such as Jake Raby (such as the compression ratio issue) but the majority of it still applies today because in essence the technology is the same with a motor design dating back to the 1930's.
Everyone is entitled to have their own opinion