What Cam should I be using? for a Type IV Motor

notchy · Samba Member Joined: March 01, 2005 Posts: 42

Hi

I have recently rebuilt a Type IV motor to the following spec but have an issue when using it for off road steep hillclimb (mud / rock) competition in that the engine stalls in gear when any grip from the wheels are found. I then have the slip the clutch very quickly to try and stop it from stalling, I'm told that the cam installed is mild and should be ok, but I really want this motor to produce very good bottom end torque, any recommendations?

2056cc
Vanagon large valve heads
2-2-1 Exhaust with muffler
Webcam 270 degree .423 valve lift
40 DCNF Carburector
8.2 CR
009 Distributer

notchy · Samba Member Joined: March 01, 2005 Posts: 42

Re-posted, anybody?

jsturtlebuggy · Posted: Sat Nov 19, 2011 10:42 am Post subject:

When you installed the cam did you degree it? check it against the specs on the card?
Cam you have is very mild, should work for your purpose.
What do you have for carb setup, duals or a single DCNF?
Weber DCNF's do not have the best float bowl venting system for off road use. They flood out in rough terrrain and any steep angles.
Weber IDF or Dellorto's DRLA carbs have a better float setup for using off road (both still need some work for venting) that help to keep from flooding out.
Tell us some more about your Vanagon cylinder heads, how big of valves, how big of ports?
What kind of exhaust?
Pictures of setup would help.
_________________
Joseph
Fair Oaks/Orangevale, CA
Elrod Motorsports
Motion Tire Motorsports
Having fun with Dune Buggies since 1970
Into Volkswagens since 1960

Jake Raby · Posted: Sat Nov 19, 2011 2:16 pm Post subject:

I will bet the 2-2-1 exhaust is the issue. I'd bet 100 bucks on a proper 4-1 or 4-2-1 would pick up a ton I tube ability and would find power. No 2-2-1 system I have ever tried to work with on a TIV has worked... The engine was always rich and could not be tuned..

Inefficient exhaust KILLS torque especially at low speed where chamber filling is so important.
_________________
Jake Raby
Raby Engine Development
www.rabyenginedevelopment.com
"I've never given anyone Hell, I just told them the truth and they thought it was Hell"

jsturtlebuggy · Posted: Sat Nov 19, 2011 2:45 pm Post subject:

That is one of the things I was wondering too Jake, about the exhaust.
I thinking he may be using the stock exhaust manifolds.
With his posting of using Vanagon heads first thought is square ports and limited amount of exhaust system available for them.
_________________
Joseph
Fair Oaks/Orangevale, CA
Elrod Motorsports
Motion Tire Motorsports
Having fun with Dune Buggies since 1970
Into Volkswagens since 1960

Jake Raby · Posted: Sat Nov 19, 2011 3:22 pm Post subject:

Yep and using those is a total and complete waste of time, money and resources. Period.
_________________
Jake Raby
Raby Engine Development
www.rabyenginedevelopment.com
"I've never given anyone Hell, I just told them the truth and they thought it was Hell"

notchy · Samba Member Joined: March 01, 2005 Posts: 42

Hi Joseph / Jake

Thank you for the great response, I don't return home until next Friday, so I will get the head details then and some pictures. At the moment I'm actually running a Stainless Steel box exhaust (which I don't think is helping at all) but I going to get a local company make a 4-2-1 SS system but I want to retain the 422/412J tubes (they been modified for the square port heads) as it allows some heating into the car and keeps the system compact as I need the ground clearance for the off road competition.
I take it the 411/412J tubes will be ok to use? with a bolt on 4-2-1 manifold with a muffler attachhed. I will check the degree of the camshaft as well.
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notchy · Samba Member Joined: March 01, 2005 Posts: 42

Hi Joseph / Jake

Here is a picture of the 411/412 J tubes which I cut and rewelded to the vanagon flanges and then ported the tubes to remove the weld etc. The car is in as we speak for a new SS exhaust system.

The heads have 42mm inlet and 36mm exhaust and is ported. CR is set for 8.2:1

I haven't degree the CAM as yet but swapped out the 009 with a vacum distributer and this made the bottom end a bit smoother, I also added in a fuel regulator and set it to 2psi.

[img]http://www.thesamba.com/vw/forum/album_cat.php?cat_id=31[/img]

notchy · Samba Member Joined: March 01, 2005 Posts: 42

Picture added

Image may have been reduced in size. Click image to view fullscreen.

jsturtlebuggy · Posted: Sun Dec 04, 2011 3:52 pm Post subject:

Yes those type IV heater box pipes will work as they are seperate pipes coming off the exhaust ports.
Going with 4 individual pipes all the way to the collector is the best way to make and exhaust system.
Do realize that the type IV pipes will restrict flow and how much depends on valve size and engine size.
They were made for a 1700cc engine and your engine has more CCs.
Even though I have used the same type IV pipes with a old 4-Tuned exhaust system it great for torque on my own 2056, I feel a larger size on the primaries would help in the higher RPM range.
_________________
Joseph
Fair Oaks/Orangevale, CA
Elrod Motorsports
Motion Tire Motorsports
Having fun with Dune Buggies since 1970
Into Volkswagens since 1960


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