Cotton AeroVee 0795

[vwglenn]

Hmmmm...I must admit, I don't ever recall seeing a cover like that before. I do have a little concern about the whole setup though.

Here's a blurb from the Gene Berg site as to why...

"The only proper way to achieve full flow oil filtering without pressure or flow loss is to plug the pump, use a full flow cover, drill and tap the main oil gallery to return the oil. All other methods such as pump covers or pumps that have inlet and outlets all together at the pump reduce the pressure and flow of oil from stock and can cause damage or a premature failure to the engine."

Now this is an old quote and things may have changed but it's the conventional wisdom I remember. I'm sure the guys @ Sonex have considered this and chose not to do it for whatever reason (clearance? flow tests?). I imagine oil flow is pretty important in the turbo application.

[Sonerai13]

Glenn,

The turbo oil pump is a completely different unit than used on any of the non-turbo applications. They are not interchangeable. The "maxi" oil pump that Bryan has is used when installing a bottom-mounted oil cooler. This was typical on Sonex installations until a few years ago, when we switched over to the top-mount (which Bryan is doing on his engine). The oil pump used in the bottom-mount cooler installation is not used on any other version of the AeroVee.

The bottom-mount cooler installation was used on hundreds of AeroVee installations for many years, and has shown no issues with pressure or oil flow. The only drawback is the external hoses and the cooler location itself, which is in the way when doing oil/filter changes. The top-mount cooler eliminates all external oil lines (to the cooler) and is completely out of the way for all normal maintenance procedures.

[rizzz]

Brian,
I have the classic full flow filtering setup Glenn mentions above on my engine,
This requires a pump and cover plate with only an oil outlet, the oil is returned to the engine through a hole that's drilled and tapped in the case just above the pump. The oil galley that normally leads the oil from the pump to that location is plugged so the oil is forced out the outlet in the pump cover.
the last picture on my kitlog page shows this here:
http://mykitlog.com/users/display_log.p ... 842&row=15
You can see the AN fitting above the oil pump slightly to the left where the return line will go to (not yet installed here).

The AeroVee pump & cover basically achieves the same thing but it is a much easier setup as it allows the oil to return to the pump cover, after going through the filter the oil will then just return into that galley (which is plugged in mine), as it normally would with no external filter installed.
This is the "easy way" to full flow your engine as it does not require you to drill & tap oil galleys in your case.
Indeed Gene Berg & Bob Hoover both list concerns about this setup but always keep this is in the context of using these engines for street racing applications etc.
As Joe mentions no AeroVee has ever shown any problems with pressure or flow. I think you'll be fine using your pump & cover to connect an external oil filter if that's what you want to do.

[vwglenn]

Cool beans Joe.

I think the top mount cooler is brilliant. My initial confusion had to do with loops and my misunderstanding about changing/adding pumps. That confusion sent me down the rabbit hole.

For the record. I've run a filter pump, a full flow system, and plain old stock in my VWs in the last two decades. None have ever blown up on me. My first VW had the filter pump on it and I flogged on that engine for years. I did not treat it gently at all and it made it to 100k and was still running when I took it apart.

All the "maxi" pumps I've seen have a totally different cover on them which are not nearly as deep as the cover on the Sonex pump. VW oil pump covers need to be more shallow to clear the tin and pulley which might contribute to restrictions. Most of the time that inlet and outlet are on the same side of the pump cover too. The concern about restrictions also has a lot to do with RPMs. You're average VW will cruise at 3500-4000rpm as it rolls down the highway. I think most VW gearheads will agree that the stock system works just fine. In race applications the RPMs can be pushed to nearly double that of the cruise numbers so more oil is probably a good thing. An Aerovee should never see that kind of RPM so there should be little concern of oil restrictions from the full flow system they use.

Even so, given the displacement of the Aerovee, I'd go with the widely accepted full flow system with the tapped case if I were building one. Either that or eliminate the full flow system if possible to increase simplicity.

Once again, In Bryan's case, I'd run a filter since I already have all the associated equipment in place.

[Bryan Cotton]

So we dropped the drive gear - look by the blue mark:


That stuff is soft. I had to file off the edge to get the gears to run freely. So - is it junk or as long as there is oil pressure am I good?

[vwglenn]

A lot of VW guys put a effort into blueprinting oil pumps in an attempt to get them as close to perfect as possible. Is that ding a big deal? Probably not. Will it effect it's ability to produce pressure? Probably not. Would I change it? Yep. Only because I would hate myself if I didn't.

[DCASonex]

As Glenn stated, probably not a problem, but one check I would do if using this is to place the blue marked face down on a piece of fine sandpaper on flat surface and lightly move it around. Should see even contact over entire surface. Might find it is high next to the dented area and this check will indicate extent of damage. It must be brought back down to level, and if minor, the sandpaper on flat plate can do that.

David A.

[Bryan Cotton]

I came up with a solution for the pushrods. I put another shim under the rockers and the alignment was still good. Now I have a boatload of adjustment as the motor runs in. Adam now knows how to find TDC and adjust valves:


As a kid I learned good judgement to avoid stripping holes. How? Well, I stripped a bunch of holes, of course. Adam did his first one on the fuel pump blockoff plate. All the threads came out nicely like a spring on the bolt. We have a helicoil lesson in our future. I assume they have metric helicoils.

[vwglenn]

LOL! yes they have metric helicoils. You need to step on the gas. I have 10 bucks riding on this thing!

[DCASonex]

Bryan, and Adam,

Good judgement comes from experience. --- Experience comes from bad judgement.

David A