Another Rookie 3.0L rebuild

[jdbunda]

Here is a question that I have not found much good information about. My fan shroud is looking pretty shabby, lots of crusty layers of red paint. While pondering that, I thought I would check into just getting a different one, but discovering that there are shrouds, and there are shrouds. Mine has a riveted-on duct for the oil cooler. Looking at the various offerings in the used parts forum, I see there are many that don't have this duct, or have a different-looking one. For this motor, I like the idea of getting as much airflow through the oil cooler as possible, so it seems like a good idea to stick with this design, or am I missing something?




By the way, this picture is of my shroud AFTER degreasing and power-washing. The black is baked-on discolored paint.

[David Borden]

Once you have gotten all the oil off it, you can get a soft sanding block and some wet/dry sand paper and sand it smooth and re-spray. Using water while sanding will make it much quicker and easier to do.

David

[casor]

John - While your shroud looks a little different than the ones I pulled off a 78 3.0 SC and my 74 2.7 911, I do believe that the only way to properly refurbish these things is to take them down all the way. This primarily involved drilling out the rivets holding on the internal metal duct, which then can be refinished separately to eliminate rust, paint chips, and bent sections. Also, the inside of the shroud is very difficult to properly clean with the internal metal duct in the way. Not sure if yours has other parts but, if you can take them off and deal with them in pieces, you'll be much happier with the result, believe me.

Re-riveting the internal metal duct is surprisingly easy to do and it was so nice to work with stuff that was now "almost new". To take off the paint on the shroud, there is a paint remover available for fiberglass. Do not, under any circumstances, glass or alox blast this part. I would also consider seeking out a good body guy on how to refinish this part - I particularly like the epoxy paint available from Klass Kote and have used that on my cars, motorcycles and scale model airplanes w/o drama.

Epoxy Coatings - Colors, Clears and Primers - Klass Kote

Attd is a photo of a section of my refinished shroud which did not have paint on it - it is the factory finish just cleaned up....


Rob

[mreid]

You can always pick up one of these Amber shrouds from our host. They require trimming, but fit really well.

[jpnovak]

John, Its pretty easy to strip paint off of these using the citrus style strippers from Lowes or HD. Just brush it on and let it sit. These should not damage the fiberglass underneath. Eventually you will get down to the original color of the fiberglass which might be, black, yellow, green or red. There are threads about dying the fiberglass but usually a good strip, clean and reshoot is the way to go.

krylon Fusion paint is generally the best choice for a rattle can covering.

[jpnovak]

Mark, The thing I do not like about some of the amber fans is the lack of separate cooling air channel for the engine mounted oil cooler. Some have them, some don't. I know the early engines, such as the 911R, did not have these channels but something like your 3.2SS needs this channel.

[jdbunda]

Thanks for the replies, guys.

Agreed 100% on the oil cooler duct, Jamie. As much oil cooling as the bigger motors need, I don't think I would put on a shroud without one unless I had a really strong alternative oil cooling story. If you check Damon's Series 900 page, he shows at least three versions in the photos of his new shrouds, some with the duct and some without. I see that our host offers the Sheridan shroud along with a similar fiberglass oil cooler duct that could be fitted to make it look like mine.

I'm going to try to re-use mine. It might need some glass repair, some of the attach holes are mangled, etc. As Rob points out, to do it right, I will need to remove the duct. It looks like factory red under the peeling paint. There does come a point where the a new one starts to look attractive relative to the amount of work! But hey, it's the journey, not the destination, right?

[Mick_D]

I am finding that it's mostly the money that determines how fast things move along.

[lobster]

One more thing about rocker shaft removal. I think(I'm doomed already and I PRAY someone with more experience than me chimes in on my behalf) that the risk of damaging the rocker shaft bore using a long allen is worth getting a good 1/4 drive/5mm socket. The rocker shaft bolts will just pop and when they do, could throw the allen just enough to nick the wall. Have you had leaky rocker shafts? A mess. Its a questionable sealing arrangement to begin with. The tools make it happen so much easier and with less damage. In this case, a pro engine builder friend who built my motor 12 yrs ago and 120k miles, w zero issuses, had a Snapon racket and Stahwille stubby hex socket that fit right in there. I now have the same set up and did my rockers the other day(serious). It is a GREAT setup. So secure. Its an area you want to be extra careful with. Run RSR seals as well. SO simple.
I'll shut up now.
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[jdbunda]

Dane - I agree that a 1/4" ratchet with a short 5mm allen socket that can fit in the adjacent space is FAR better than feeding a long extension through. I do feel like I was able to remove mine without any damage, but I would much prefer doing it with better suited tools, thanks.

[flmont]

I used what was known as 964 cam's in my 81' 3.0 ltr build ,it was a nice running engine,with factory F.I.,..if I were to use carbs,..they say 240 HP easy,...FM

[cgarr]

Heads got here in great shape! Good packing.




Sent from me

[jdbunda]

Thanks, Craig - I can't wait to see them looking more like the ones in the background! I just hope my indexing marks are still visible afterwards...


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[casor]

John - there are a few ways to repair fiberglass. Note that you will most likely see the repair unless the shroud is painted and then I would only use epoxy for this.

I have repaired a number of old school glass BMW fairings using this method: First clean up the area with acetone or lacquer thinner. Do not use paint thinner. Wire brush the affected area with a small but stiff wire brush. Clean again with LT. Analyzed the affected area - will the eventual repair be reasonably supported - ie, a crack is easy, holes are worse and edges chipped/holed are worse yet - including munged up mounting holes at the edge.

For a crack, "V" out the crack with a cone bit in a Dremel, going slightly beyond the crack. If cracked on both sides, "V" out both sides so that the "V" meets in the planer center of the crack. ie both sides should look the same when you're done. Sand with 150 - in the crack and slightly around. Buy some 1/16 fiberglass strand from Fiberglast and fill the crack (both sides - one at a time) with this stuff - dry. Apply thin cyanoacrylate ("super glue", "CyA"). It will wick and smoke. Sand and do again until the crack is completely filled. Level, and apply 2-part body filler or 2-part polyester body filler resin to finally fill and level.

For holes, clean and sand as above. Make small "V" cuts around the perimeter of the hole's edge with a Dremel. Apply packaging tape to the outside of the glass pc, over the hole. Now working from the inside, depending on the size of the hole, you can do a few ways. The CyA thing above, or use Kitty Hair polyester resin and strand or you can mix up JB Weld but mix in the 1/16 strand in the matrix. Fill the hole, being careful to not induce bubbles down against the tape.

Edge holes and munged mounting holes: These are tough. I like to use a combo of glass cloth pcs (2 or 4 oz), glass strand and JB weld or Kitty Hair. You will most likely have to fill the entire mounting hole and redrill later. Run your perimeter cuts a little deeper or make slicing cuts so that the glass/schmutz matrix runs beyond the affected area and is therefore able to support the repair hanging in mid air. The packaging tape thing can be used here also.....
Rob

[jdbunda]

Thanks, Rob. Will evaluate when I get all this paint off - it actually seems to be in better shape than I thought. The shroud was originally yellow under what looks like three or four different coats of red, and one of oxide primer. The paint was sprayed on thick. Getting all of that off is messy and time consuming, I have just been working at it with citrus stripper.


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[casor]

You're welcome John. You're probably too far along, but you could have used a more aggressive stripper - like the aircraft stuff - once you found that the paint was on thick. Nevertheless, when it's like that, it will still take multiple applications. Make sure you neutralize that stuff - any stuff - before you go to paint. Probably alot of water and maybe a swipe of lacquer thinner. If you use epoxy, you won't need a primer since it sticks so well, unless you want to elim surface imperfections. As an aside, if you're respraying yellow, do not spray it over a gray primer - it won't cover any dark areas, like from the repair. Always use an uninterrupted coat of white primer or paint - epoxy - under anything you paint yellow. Yellow is a notoriously weak color.

Rob

[jdbunda]

Yeah, a stronger glass-friendly stripper would have been great.

I think it's unlikely this is the original shroud for either the car or even the motor, so it doesn't need to be yellow. After seeing the original finish, I am curious if anyone has ever tried to re-apply a gel coat to one of these, and whether it would be cost-effective or desirable to go that route. Seems like it might be stronger and maybe more impervious to staining than rattle can enamel. Plenty of boat repair fiberglass shops in Austin - I might make a few calls.


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[casor]

Never thought of using gel coat which an interesting idea, but that stuff is heavy. Epoxy, man - it doesn't dry, it cures. And it won't come off. Forget about the rattle can.

[michael lang]

nice progress up to this point John, as far as your cooling shroud is concerned, just a suggestion but your engine might be better off with a replacement shroud from a Carrera engine but more importantly worth it in the long run from a time savings standpoint. I would think someplace like L.A. Dismantler, Planet 9 or DC Auto would be good places to get recycled parts for not a lot of money.

[jpnovak]

John, Leave it yellow. Yellow is correct for the car (72T). With the MFI-EFI fuel system it will look like the ultimate stock sleeper.