Working to fix my 91 C4 oil leaks, noticed some corrosion on the valve covers and thought it will be a good idea to replace them with Aluminum ones. I am hoping for recommendations on who makes the best ones. Thanks for your advise..

 

Rennline makes a nice set. Tarett Engineering makes a set too.

Hargett makes the "nicest" set. Also most expensive.

 

Thanks for your thoughts, sounds like a set of Hargett is what I'm am looking for then. any suggestions as to best place to buy them? Thanks

 

I brought them direct from their U.S. web site and had then exported over to me in the UK .

I had to pay the import duty but worth it for the quality as no issues after 6yrs use and a few tappet services .

 

Rennspeed also sells the OEM aluminum ones for $195 a set.

http://www.rennspd.com/P_Detail.asp?PID=824

 

I have Tarret lower covers and Rennline uppers. Pretty similar except the finishes.

 

Unless Hargett has modified their design and production to ease the razor sharp edges and to include wire holders, and to include a loop on the end of the lowers to hold the rear-most plug connector, I wouldn't call them the best.

I have them. I like them. Don't get me wrong. They were at the time, the least expensive, good option. But I did a lot of work to make them useable. Eased the edges, because they cut your fingers if you don't, and then drilled and tapped holes to add the oem wire holders, and then painted the outside of the covers so they don't oxidize. Now they are acceptable.
I haven't looked at covers for a while, but I see out there, rennline, which look like a nicely made cover, oem aluminum, which honestly, later someone buying your car since he will know next to nothing (kids these days), will so appreciate "oem Porsche" as a label, he will probably pay more for the "authenticity" , and then further pay more for the "too stiff poly bushings" you added in a fit of trackness....
And then you have Eagle Day, which no one seems to talk about likely because no one would ever pay the price, but they were always far and away the best quality as far as I could tell. But way too expensive with the others on the market.
Enjoy the search, don't take it too seriously, all the covers that are not oem Porsche magnesium are good and do the job. And even the mag covers are good when new...they just don't last long enough...

 

Thanks Guys, I value information. This C4 has some oil leaks go figure at the valve covers and both upper and lower are oxidizing. The magnesium is bubbling so its time to put some Aluminum ones on. I normally prefer to stay with original equipment but for these valve covers I just want something that will solve my oil problem.

At the moment I am leaning toward the Hagerty or rennspeed, I finally cut my CAT off and its worse than i had thought, so next step is to clean and then remove the covers to see how my head-studs are holding up.

Please keep the information coming again I am a newly to the 964 world but have had other older 911's its amazing to me how many parts PORSCHE has added to these car??? But i do like how it drives.

 

Why replace your covers; what about getting them bead-blasted (NOT shot-blasted) powder coated and then finally flatten the mating surface off on a wide strip of emery on a truly flat surface. I did that with mine and no leaks, the engine looks nice and it is a lot more "cost-effective" than replacements. Rgds, Les.

 

I'm lead to believe that the replacement covers from Porsche are now made of aluminum too. I'm having some put on next week because the imagine auto ones I've got at the moment (no longer made) have never sealed as good as I would like.

 

Please let us know how the Porsche covers work out, I am in the market for a set of lowers, torn between the Porsche or the Rennline
PS. I had the Imagine Auto covers as well and they leaked just as bad as the old Porsche ones.

 

I was hoping to report back by now, however.....the covers were ordered and were about to be dispatched from the factory in Germany but Porsche put a stop on their release at the very last minute because of 'quality concerns' with the covers. So my existing imagine auto covers have had to go back on with fresh gaskets.

 

Thanks for posting anyway. Please keep us up to date.

 

AFAIK they superseded the magnesium covers with aluminum in 92. All the later model 964's I have worked on have aluminum factory covers my 90 came with magnesium.

Unfortunately they are $224 each from sunset.

 

I'm getting a gearbox refresh so have the engine out in my garage and a bit of time to go over it. My '90 C4 has Magnesium valve covers, which are corroding. I'm doing a valve adjust and the first cover off has left a layer of Magnesium on the gasket. It's a false economy to put these back on.

Do we have a definitive recommendation that a particular replacement cover will work out of the box? I ask as I see some posts that the grooves are too deep in some brands meaning a skim has been done to allow the gaskets to properly seal. I just want to fit them, not have to visit a machine shop to adjust what are very expensive items.