TheSamba.com :: View topic - Bought a used VW w/ modified motor

Fri Nov 21, 2008 1:40 pm

Hi,
I picked up a used Karmann Ghia with a modified 1600 motor. The engine, besides having dual carbs, has the following modifications:

92mm pistons, 69mm crank, 120 degree Engle cam, 42x37mm heads w/ dual rev springs.

I don't know these cars enough to know exactly what I have - but I think someone here probably can tell me off the top of their head.

What is the displacement? The compression ratio? What mods do these changes imply?

From what little I've driven the car it seems to run fairly well other than it will need some carb sync'ing I think..

Thanks...

Fri Nov 21, 2008 1:44 pm

1835cc

CR unknown without pulling the top end

The heads are waaaay big for an 1835. With those heads and that cam = high-end power. High-end to the point where the stock components will vibrate apart in short order if you keep you foot in it.

Fri Nov 21, 2008 1:45 pm

1835cc

Fri Nov 21, 2008 4:17 pm

visket wrote: 1835cc

The heads are waaaay big for an 1835. With those heads and that cam = high-end power. High-end to the point where the stock components will vibrate apart in short order if you keep you foot in it.

I don't completely agree with that. The larger valves will rob him of a little bottom end, but the 120 is a good cam and makes decent low end. If the crank is CW he should be fine.

Fri Nov 21, 2008 4:34 pm

Hmmm - something's fishy - I could have sworn it said a 130 cam when I replied. A 120 is better, but we're still looking at a 6K+ rpm cam/heads. Match that with unknown (balanced or not?) internals, and it might deposit one of those nice heads into the Porsche he's racing.

A stock throw crank and big bore pistons doesn't necessarily mean balanced. The PO did spend some money for some nice heads, so maybe he spent the money to get things balanced. BUT, if there was a CW crank, that would have probably been on the "mods list".

The motor has been modified to produce quite a bit more power than stock, but at a much higher rpm than stock internals were designed to live with.

Try to find out more about the crank, rods, balancing, etc..

Fri Nov 21, 2008 5:43 pm

luminarycrush wrote: Hi,
I picked up a used Karmann Ghia with a modified 1600 motor. The engine, besides having dual carbs, has the following modifications:

92mm pistons, 69mm crank, 120 degree Engle cam, 42x37mm heads w/ dual rev springs.

I don't know these cars enough to know exactly what I have - but I think someone here probably can tell me off the top of their head.

What is the displacement? The compression ratio? What mods do these changes imply?
From what little I've driven the car it seems to run fairly well other than it will need some carb sync'ing I think..

Thanks...

It means fun!!!
Run it like you stole it and worry about it later :D

Fri Nov 21, 2008 8:21 pm

'Specially in a Ghia!

There are multiple VW Drag Days at Irwindale Raceway (I forget what city it's in...) every year. Make plans to attend. $15 entrance fee + $15 racing tag = PRICELESS fun. I have had more fun doing Drag Day than having sex. And, I own more 1st place trophys (5) at Drag Day than the other thing as well.

For your $15/$30 bucks - time slips, head-to-head racing, The Tree (all LED), the crowd... That's where to go unload.

Have a bunch of fun. Save a few buck every week for a "new motor" fund.

And do not race on the street.

Mon Nov 24, 2008 8:28 am

Thanks for the replies guys.

That's all the info I can probably get about this motor aside from it does have a lightened flywheel and heavy duty clutch. The PO is probably not reachable.

I'm planning to do a Megasquirt/intercooled turbo upgrade to the car and while I really don't think I'll be running more than 7psi boost I'm going w/ full EDIS-4 and knock sensor so I'm hoping to compensate if the compression is a bit higher than what's turbo-friendly. I'm looking at using a TB28 for a 1.8L Jetta? turbo, the same a friend is using on his turbo'd Beetle with good results.

I'm about to the point of injector sizing & thought that I really needed to know what I had here.

I just completed the 5-lug conversion and am running Porsche 7" 993 cup wheels on all corners. Now it's time to get the engine/wiring/plumbing done & the instrumentation setup & then it is to the paint shop....

Mon Nov 24, 2008 8:44 am

luminarycrush wrote: I'm planning to do a Megasquirt/intercooled turbo upgrade to the car and while I really don't think I'll be running more than 7psi boost I'm going w/ full EDIS-4 and knock sensor so I'm hoping to compensate if the compression is a bit higher than what's turbo-friendly. I'm looking at using a TB28 for a 1.8L Jetta? turbo, the same a friend is using on his turbo'd Beetle with good results.

My suggestion would be to leave the current 1835 alone and build a 2nd complete engine starting with a new case for your turbo engine. That way you will know exactly what you have and everything will work in harmony. You will also be able to drive the Ghia while building the 2nd engine. Then sell the 1835 and recover more of your money.

Mon Nov 24, 2008 8:51 am

Why dont you spend a couple of $ taking it to a rolling road for a tune to get your carbs right and to see what power it makes. From the peek Hp you will be able to tell if its decent. 120hp would be a good 1835.

Mon Nov 24, 2008 9:28 am

krusher wrote: Why dont you spend a couple of $ taking it to a rolling road for a tune to get your carbs right and to see what power it makes. From the peek Hp you will be able to tell if its decent. 120hp would be a good 1835.

Very good point :D