TheSamba.com :: View topic - How to identify a Type IV camshaft / camshaft types

Mon Mar 23, 2009 9:05 am

based up a lot of time wasted trying to get the correct camshaft, thought i would shared the experience. Here is a simple way to id an OG Type IV camshaft. I also spoke with Web Cam and they follow this as well in general.

At Center Camshaft Journal

no rings = hydraulic lifters w/ manual transmission

2 rings = (1 each side of journal)- hydraulic lifters w/automatic transmission

1/2 ring = solid lifters(72-74 carb engine)

1 ring = solid lifters(75> Fuel Injected engine)

Example below: has 2 rings so is from an automatic w/ hydraulic lifters):

Mon Mar 23, 2009 7:20 pm

SGKent wrote: based up a lot of time wasted trying to get the correct camshaft, thought i would shared the experience. Here is a simple way to id an OG Type IV camshaft. I also spoke with Web Cam and they follow this as well in general.

At Center Camshaft Journal

no rings = hydraulic lifters w/ manual transmission

2 rings = (1 each side of journal)- hydraulic lifters w/automatic transmission

1/2 ring = solid lifters(72-74 carb engine)

1 ring = solid lifters(75> Fuel Injected engine)

Example below: has 2 rings so is from an automatic w/ hydraulic lifters):

Thanks for sharing that excellent piece of information. Could you clarify what is meant by 1/2 ring, please?

Mon Mar 23, 2009 7:51 pm

This would be a great sticky, IMO. But I'll bookmark it just the same.

Thanks for the info.

Mon Mar 23, 2009 8:45 pm

Quote: Could you clarify what is meant by 1/2 ring, please

when I see one.

Mon Mar 23, 2009 10:57 pm

Thanks for that informtion, it helps to explain why I'm currently rebuilding my 76 2.0 litre which failed with a flat cam lobe and destroyed lifter.

The PPO's mechanic did a top end rebuild and replaced the hydro lifters with solids but left the old hydro cam in place :shock:

Good luck with your build, hope you get many trouble free miles from it.

Cheers.

Tue Mar 24, 2009 6:34 pm

I just looked at the old cam from my solid lifter, manual trans, 1974 dual carb engine. It has two solid rings. I also remembered having an old HVWs mag article on the type 4 engine (July 1990). I pulled it out of the file and it said:

"...there are three different stock cam grinds; two for use with mechanical lifters and one hydraulic grind. Of the two solid lifter models, one has a high lift and duration for a manual transmission while the other is a little tamer for the automatic. To identify these cams from each other you have to look closely at the casting for two raised rings located on both sides of the center bearing journal The hydraulic cam is void of any rings, while the solid grinds will have two rings at both sides of the bearing surface - and they don't have to be complete rings either. Many casting rings extend only 180 degrees around the shaft. To determine whether a solid cam is the larger of the two requires either a visual inspeciton with a sharp eye , or dialing it in using a degree wheel and a dial indicator."

So, that kind of answers what a half ring might look like. Also indicates that solid lifter cams can have two full rings (which I can visually concur with).

Tue Mar 24, 2009 7:04 pm

I think what I have learned from this is that if you have manual trans with solid lifters you are ALWAYS looking for a 1/2 or 1 band camshaft.

If you have an automatic you must have a two band camshaft. If you send it to be reground it will likely be reground with a hydraulic grind unless you say otherwise and you had better check when it comes back.

If you have a manual and late hydraulic (GE for example) you want no bands.

Sun Mar 13, 2011 1:17 am

3/12/2011 update. Please read below.

Every once in a while a NOS T4 camshaft pops up and the questions are almost always the same - "What is it for?" I have read many such threads in researching this and after a year of research there are so many different explantions it may be impossible to determine what the camshaft really is. In fact I am somewhat stumped with facts being more muddied than they were when this thread began.

One of the posts in this thread indicated from a reliable source "The hydraulic cam is void of any rings" - Bentley agrees on page 59 of engine and also indicates that two bands means an automatic trans. If we believed this then it would look like:

Two bands is automatic (but this may be incorrect based on several other people's experiences)
1/2 to 1 band is a solid lifter manual trans
no bands is hydraulic lifter cam

An aluminum riveted gear (ending in C) indicates it is a late camshaft so the grind is probably tamer than the early solid. All this said, when you read articles you will suddenly find one engine that completely throws this off - like VW just stuffed whatever they had that day into the engine - or maybe VW just lost control of this process.

Here is something written in a thread on factory cams, it indicates Bentley may be wrong and in fact it also agrees with other posts I have read where someone pulled apart a known original engine:

Scott wrote: Quote: for instance i have one cam here that came from a 76 Bus engine, GD code, manual transmission and solid lifters. it has two cast rings, so that seems to contradict one of the items above about the auto cams having two rings. there is no note in the VW parts fiche about cams being different for automatic tranmission versus manual. i know there is a paragraph in the green bentley to this effect, but it is not supported by any other factory literature. i wonder where the editors of the bentley obtained the information in that paragraph on page 59 of their book.

The conclusion I have is that even if you find one in a box it may not be what you think. Someone like WebCam etc probably has more control on the process than VW did at the end. VW may have standardized the grinds so much at the end of the lifecycle that it did not matter to them which camshaft they used. Proof of this is to be found in one thread from Europe where a camgrinder there told a fellow to effect "there are may be 5 grinds on the T4 cams just for solids with the same part number depending upon when they were made. I don't know what it is even until I put it on a machine and measure it."

Last - here is the most specific post on the subject I could find on the Internet:

Quote: Different cam timings:

411 and 914 until July -72 and manual 1700cc vans. Marked with one cast ring by the center bearing journal:

IO 12
IC 42
EO 43
IC 4

411 and 412 after July –72 and 914 After August -72 and all 912E.
Marked with one half cast ring by the center bearing journal:

IO 9
IC 41
EO 43
EC 4

T2 Cam (automatic 1,7 / 1,8 / 2.0 and mechanical lifters. Marked with cast rings at the both sides of the center bearing journal:

IO 2
IC 35
EO 35
EC 6

Cam for hydraulic lifters 2.0 (T2 and T3), no cast rings.

IO 2
IC 33
EO 36
EC Before 3

IO=Intake valve opens Before TDC
IC=Intake valve closes After BDC
EO=Exhaust valve opens Before BDC
EC=Exhaust valve closes After TDC

TDC= Top Dead Center
BDC= Bottom Dead Center

I got those timings from a reliable Aircooled VW guy and his databank in Finland...

FWIW - the early 1 full band is reported to have loped a little at idle due to vacuum issues (16 degrees overlap) so VW made the cam a little less racy (13 degrees overlap) and that smoothed out the idle, hence the 1/2 band being milder. Some sources indicated that all the late cams pretty much use the later mild FI timing curve (8 degrees overlap) but that is unverified. My best suggestion is to degree the cam if you have a factory one and see what it really is and if it will work for your needs. I have a NOS 021.109.101K and it is supposedly for a 1973 GA 914 d-jet engine w/ 7.6 CR. It has however an aluminum gear and a 1/2 band so clearly one can see that even VW and Porsche's published data conflicts with itself because aluminum gears weren't used until late and the 101K should be full band and not 1/2 band.

Sun Jul 24, 2022 2:10 pm

quote="SGKent"] Quote: Could you clarify what is meant by 1/2 ring, please

when I see one.[/quote]

Here is a picture of a 1/2 ring camshaft which came riveted with an early B gear. Looking at the close up of the top center of the lobe there is a oval spot and want to know if they are wear marks or "identifying marks" from the factory. I have never seen a brand new stock came so I have nothing to compare these oval indents too.

Questioning if these oval indents are "wear marks" from worn lifters or are they there from the factory to help "promote turning" of the lifter or something? The inner two lobes have a smaller oval indent while the outer lobes have a slightly wider oval on them but same depth. The actual faces of the lobes look quite decent which is why I was thinking factory indents as worn lifters would likely cause wear on the face of the lobes also (all around)?

Sun Jul 24, 2022 2:14 pm

That's wear.
I wouldn't use that one.

Sun Jul 24, 2022 2:58 pm

the wear comes from the edges of the lifters where they overlap on case halves. As the center of the lifter wears down, the edges of the lifter begin to touch the lobe and wear it.

Sun Jul 24, 2022 5:04 pm

Glad this came up. I have a T4 cam I was going to place in the classifieds, as I am trying to clean my garage out and pay for some projects. I bought it probably around ‘05 or ‘06 from a Samba user who advertised it as an NOS hydraulic cam. From what I see in this picture it appears to have one band, which would indicate solid lifters/FI engine. Is that correct? This is an old crappy photo. I could dig the cam out for a better shot if need be. Thanks.

Sun Jul 24, 2022 5:41 pm

1700cc Type 4 camshaft for automatic transmissions