Type 4 2.0 Camshaft selection

[Gnasha]

Hi, I’m building a 2.0 type 4 conversion to DTM cooling to put into a 73 Karmann Ghia.

I’m waiting for the machined parts to arrive and my thoughts are now with camshaft selection for the following spec:

The majority of the engine will be standard, mainly used for road use and some motorway cruising. Reliability economy, and a little excitement thrown in would be the main requirements.

Twin 40 IDF Webers.
Larger 1800 valve heads (3 angle).
Electronic Distributor.
Running on 95 Octane fuel
UK Based.

How much would the choice of compression ratio affect my camshaft selection?

Any advice would be much appreciated for a first time aircooled builder.

[sideshow]

I purposely underbuilt mine, 1.7 heads, 8.1 or so CR, 96mm, webcam 86. It runs well on pump gas in both the ghia and truck. Stopped using it for the simple reason, poor forward visibility.

However it was a great summer engine, but inferior to one with heater boxes.

[Gnasha]

I purposely underbuilt mine, 1.7 heads, 8.1 or so CR, 96mm, webcam 86. It runs well on pump gas in both the ghia and truck. Stopped using it for the simple reason, poor forward visibility.

However it was a great summer engine, but inferior to one with heater boxes.

Thanks for the response

I forgot to mention I will be using heater boxes (UK climate) which will a signigicant factor in camshaft selection. As this is my first aircooled build, I also want to keep it fairly simple, with decent performance.

I assume the poor vis is in the Ghia?

[sideshow]

The ghia was worse, I tried a couple failed attempts at a stale air heater with poor results. I couldn't figure out how to recycle heater boxes like the 411 type with the DTM.

[Gnasha]

I didnt know there was a capability to recycle heater box air, ill need to look that up

[cal 67]

It should be the opposite. Camshaft choice should affect compression ratio...unless you have nowhere to get your heads flycut or barrels machined.

How much rpm are you looking for? 5000 rpm is the stock limit. Do you want to rev beyond that?

[sideshow]

Aside from being hard to find the 411 heater boxers are not anything like the fresh air beetle boxes or the bus heater boxes, no heat sink! just sort of an air channel to feed the gasoline heater.
You can see the current repo version here at Cip;
https://www2.cip1.com/ProductDetails.as ... -256-091-C

But the big down fall is when trimmed for length (not needing to clear the factory blower shroud, and that eliminates the fresh air in fitting) I didn't fully figure out the on/off or the to the body either. The DTM at one time had a offering for fresh air but Jake pulled it from view.

So never figuring out an elegant way to feed an up right converted heater box, turned me back to type-1s. I miss the soft pedal of sprung center 210/215mm disks and the superior idle/off idle behavior, but forward visibility is king

[Gnasha]

It should be the opposite. Camshaft choice should affect compression ratio...unless you have nowhere to get your heads flycut or barrels machined.

How much rpm are you looking for? 5000 rpm is the stock limit. Do you want to rev beyond that?

Cal67 thank you for your response.

This is my first aircooled build so I'd like to keep it more or less simple with minimun machine work. It will only ever see the road and motorways/freeways so I think max 5k rpm with the cam arriving on song about 2k rpm? I'd still like it to "behave" during slow town work. What CR would suit these requirements. I'm prepared to buy the cam and adjust the CR to suit, shims under the barrrel etc.

This is becoming more complicated as we speak , here's me thinking somebody has done something similar in the past and I could just copy how wrong I was.

Thank again

[Gnasha]

Aside from being hard to find the 411 heater boxers are not anything like the fresh air beetle boxes or the bus heater boxes, no heat sink! just sort of an air channel to feed the gasoline heater.
You can see the current repo version here at Cip;
https://www2.cip1.com/ProductDetails.as ... -256-091-C

But the big down fall is when trimmed for length (not needing to clear the factory blower shroud, and that eliminates the fresh air in fitting) I didn't fully figure out the on/off or the to the body either. The DTM at one time had a offering for fresh air but Jake pulled it from view.

So never figuring out an elegant way to feed an up right converted heater box, turned me back to type-1s. I miss the soft pedal of sprung center 210/215mm disks and the superior idle/off idle behavior, but forward visibility is king

Thanks for that sideshow. I toyed with the idea of a burner/heater for the UK weather, but got a good deal on two heat exchangers. They will need to be fabricated to suit the DTM requirements when the time comes.

On another note I've decide to stick with the hydraulic lifters, which will no doubt limit my choice of cam even further.

[Clatter]

Search for user 'Clkwork' or 'Clockwrk' or something like that..

He did a nice set of heater boxes for his Ghia.
Required a bit of fab work, however..

I'm in the process of building a set of those to use in a type 3,
Simply adding strips of metal to increase the internal surface area.
We'll see in time if it works or not.
Some other steps need taken to 'straighten' out the forward end of the tube as it comes to the car.
I ended up using bus control boxes after a bit of fab.
Buried a dozen(?) pages back in this painfully-long build thread here --> https://www.thesamba.com/vw/forum/viewt ... p?t=581759

[Gnasha]

Search for user 'Clkwork' or 'Clockwrk' or something like that..

He did a nice set of heater boxes for his Ghia.
Required a bit of fab work, however..

I'm in the process of building a set of those to use in a type 3,
Simply adding strips of metal to increase the internal surface area.
We'll see in time if it works or not.
Some other steps need taken to 'straighten' out the forward end of the tube as it comes to the car.
I ended up using bus control boxes after a bit of fab.
Buried a dozen(?) pages back in this painfully-long build thread here --> https://www.thesamba.com/vw/forum/viewt ... p?t=581759

Hello Clatter,I followed your junk build a while ago,I learnt a lot about acvw's great read. I seem to remember you used a new type of insulation inside the heater boxes, did it work ok? I've also seen clkwks, hes way ahead of me with turbo's etc but great workmanship and so dedicated.
I purchased a new set of heater boxes (cheapish) but they do not have any insulation between the heating element and the cover, not sure if I should open them up or not?
Thanks for the information

[Clatter]

The link I sent you isn't my cheap junk build, but a 105-page scattered random Fastback project from hell.
To save you from having to deal with it..

The heaters I did for my Fastback will just be to keep the windshield clear on cold mornings in northern CA,
Which is a bit colder than SoCal, mind you..

I added these little 'surface area enhancers' to try and pull more heat out into the airflow.
Also note that the booster blower inlets where smoothed over, and I'm just using the fan shroud for input.
Presumably, with your type 1 shroud, you could do inputs from just a booster blower, or make some like type 1s use..


Another issue with the 411/412 heaters is that the front of the boxes 'angle' inwards towards the center of the car.
The 411/412 had a whole 'nuther layout..
Using a set of bus 'chimneys' requires some surgery.


I chose to modify the chimneys vs. modifying the boxes.
Flipped them L to R, cut and clocked, spliced to change the angles, and some brackets fabbed up..


Eventually, you can get the control boxes in the right place and facing the right direction..


Bunch o' details in my forever Fastback build I linked if you spend a year or so digging...

Your setup will be different for sure,
But it shows that you can tweak these things easily,
and the metal is nice and thick and fun/easy to weld/work.

[Clatter]

The Thermal Zero stuff has only just been tested.. Not used IRL long term, so can't say for sure.
But I welded/entombed it forever in my heaters, so I'm a believer that will gamble upon it.

Back to your cam question..

I totally respect Torbin and he is right, a 163/86b with 9.5:1 would be a stonker for sure.
That's what I'm using in the 2056 in my Fasty,
However, it will complicate the build and make it more expensive.
Chopping down the cylinders will cost you if you can't do it yourself.
Cost you even more if the guy you pay doesn't get them all the same length.. BTDT.
The 86b requires dual springs (or beehives) and there's reasons to not like that.
It also has enough lift that with stock-length valves, you might not have enough installed height,
and the valves will need 'sunk' to get the room you'll need.
Again, more time/money/trouble...

If I was spec-ing an 1800 for you, for now, with stock heaters and all..
Your first build..
I'd say stick with something that can use single springs, and not need the jugs chopped.
Web 86?
If you are going to not be hooning, and drive like an adult,
They say a Web 494 can live on shimmed singles if you're careful?

Get your heads back, and do your first trial assembly of your motor.
See where your CR ends up with the parts you have.
Your heads have been fly-cut and your case decked (right?) so see where your numbers end up,
Then pick a cam.
There's plenty to be spent on things like swivel feet and spin balancing and such before you fork over to make the thing rev.
IMHO...

Food for thought..

[Clatter]

Why hydraulic lifters?
Even if you got a set NOS for a really good price, just sell them and move forward..
Those SUCK! (don't get me started, as I'll rant..)

Also,
Don't even think about fly-cutting the heads any more than is needed to true them up.
There is an exhaust stud lurking directly under the head sealing surface that you want to preserve as much as you can.

[wreck]

Why do so many hate Hydraulic Cams ? I've a grind from a 6 cylinder Australian muscle car , it's a bit low on lift because it's for 1.5 ratio rockers but has been reliable in a 103x71 for almost 20 years and 100,000km. A good friend has a 2.6 with a dodge big block hydraulic grind with pauter rockers that pulls the same power as my Scat C55 in almost the same combination of engine bits . (approx 200FWHP) .

I read a while ago that a lot US air-cooled VW grinds are just copies of V8 grinds .