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 Post subject: Volvo Pushrod Cams
PostPosted: Thu Apr 09, 2015 9:06 am 
Haha, I just built a W24 Octo-Turbo, now what?!
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Joined: Wed Jun 14, 2006 4:19 pm
Posts: 3126
Location: Lethbridge, AB
I've been working through the suppliers lately and it appears we're becoming a little limited in what is available. The standard (read ancient) ISKY VV61/71 combo are still available from IPD. Let's not go that route unless it's all that's left. Here's what I've found.

Schneider Racing is not grinding Volvo pushrod blanks anymore. So my favorite stateside cam for street rebuilds (the 274) is NLA and the more aggressive 284 and up are also gone of course. They will regrind one for you if you have a reasonable core (most have wiped lobes) - so save your cam core (I just tossed out three as I didn't know they were stopping...oops).

KG Trimning in Sweden has been my "go to" company for Volvo tuning for several years. They have stock of their cams (I like the KG17 for snappy street engines running SU's). They are not stocking as many as before and are getting more ground. You may have to wait months, so plan ahead.

Tinus Tuning in Holland has cams on the shelf with lots of new lobe profiles and lots of experience to back them up. I'm just putting together an engine using their TT4 and we'll see how that goes. I've got faith that they will be fine.

[will add to list if anyone has more sources - recent experience only please]

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 Post subject: Re: Volvo Pushrod Cams
PostPosted: Fri Jan 01, 2016 10:15 am 
I like cake

Joined: Mon Aug 31, 2015 6:49 pm
Posts: 3
You know Isky only has 6 or 7 masters that they sell as "street flat tappet" that they sell ground on just about every brand from Chev to Volvo, download the master pdf and you can see quickly what is a VV61 and what is a VV71. My head can use a lot more lift, so I would use a VV81 for an exhaust and the higher lift lobe in the .320" for the intake.

I know Phil uses Schenider, and I had a look at their catalogue and the have many different lifts for one duration. Again I would use high lift intake lobes combined with a slightly longer, lower lift exhaust lobe from the BMC-A Mini. The exhaust just doesn't need opening as high, and it is typically the lobe that fails 1st because it has to open against 100+ psi in the cylinder which works out to 150+ psi as well as valve seat pressure. The intake opens against no clinder pressure.

Whatch out they are ground the right wat too, half the lobes taper F to R, while the others are R to F. I've seen companies grind them all tapered the same way!

AGAP.SE makes the best roller cams, but they have huge lift, probably drag race only. 1st they installed a bigger diametre middle cam bearing to allow for bigger lobes, now I think they have a two piece design, but I haven't seen one. I believe Stefan Lidqvist was using one of these for his 270HP@6500 B20. That has to be the best ever n.a. B20


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 Post subject: Re: Volvo Pushrod Cams
PostPosted: Sat Jan 02, 2016 12:31 pm 
Somehow completely sideways in 4th

Joined: Mon Aug 06, 2007 10:27 am
Posts: 211
Location: edm
B20Paul wrote:
Watch out they are ground the right way too, half the lobes taper F to R, while the others are R to F. I've seen companies grind them all tapered the same way!

AGAP.SE makes the best roller cams, but they have huge lift, probably drag race only. 1st they installed a bigger diameter middle cam bearing to allow for bigger lobes, now I think they have a two piece design, but I haven't seen one. I believe Stefan Lindqvist was using one of these for his 270HP@6500 B20. That has to be the best ever n.a. B20


Uh-oh... So how serious is it if the lobes are all ground the same way? Pressure on the front brass plate, I guess?
I'm going to assume, without having gone to check, that my yet-to-be-installed Comp is ground all one way.

On the bright side, that might be one way of ending the typical B20 light knock at slow idle, which I have determined is most often the cam gaining and losing clearance against that brass plate.

If anyone is interested, I have 6-8 "roughed in" cores I bought from IPd around 2001. Unfortunately they were in a box that got caught in a basement flood, and I am not sure if anyone would want to risk their cam bearings on a journal that's got substantial texturing from corrosion. I seriously wondered if a plater might be able to fix, but then without a lathe to refinish the journals to spec, I abandoned that idea. Not looking for much $ for them.

FWIW, AGAP also do flat tappets, not just rollers.


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 Post subject: Re: Volvo Pushrod Cams
PostPosted: Mon Jan 04, 2016 1:04 pm 
Haha, I just built a W24 Octo-Turbo, now what?!
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Joined: Wed Dec 21, 2005 8:40 pm
Posts: 3482
Location: Calgary, Ab
Good observations, Paul. Nice to think about.

Ian, I'm guessing that the bevel in the timing gear more than offsets the thrust from the lobes being tapered all one way, but I could be wrong.

Do they make B20 cam bearings in undersize condition? I kind of doubt they're easy to find, if available at all.


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