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Cooling system queries
lunar_c - March 9th, 2014 at 01:27 PM

Hi all,

Just recently got myself a 72' super beetle to restore. Unfortunately just recently it decided it would like an engine rebuild so I'm currently in the process of having the cases machined and align bored case savers put in etc.

My query relates to the dog house style tins my motor runs. When I took the motor out I noticed there was no thermostat or hinged cooling vanes like I've seen in the Haynes manual. It also says in the manual never to run a motor without them as it accelerates wear as the motor takes longer to get to operating temperature.

My motor is also missing the front engine tin that attaches around the breast plate and the engine bay and lid rubbers were half missing or totally absent.

I'm going about replacing and repairing the tins and will replace the deck lid and engine bay seals while I have the motor out but I can't seem to see replacement thermostats etc anywhere.. Did the super beetle come with them? And is it as relevant in western Australia?


modnrod - March 9th, 2014 at 03:18 PM

Gday.

Unless you live across the road from me (Midwest), at start up on a brisk spring morning for a cruise the temp would be cool enough to get the "accelerated" engine wear mentioned everywhere. The difference in engine life can be as much as a third reduced.
Having said that, overheating the thing or running it lean or over-revs will kill it MUCH quicker than that. If you live around Perth-Bimbleberry-York or up north I for one wouldn't stress too much about the T-stat. The vanes I would though, they help direct air correctly over the lower part of the barrels.
Instead I would focus on sealing up the tins and engine bay, MUCH more important for our climate. Also, buy a NEW oil cooler, don't try to clean the old one out it's almost impossible. Venturi rings are effective and cheap, then tune it right and you're laughing.

Inland and north needs a few more tricks to make them live a long life, but near the coast they will be fine.
Lots of reading here, good advice........
http://www.awesomepowdercoat.com/thermostat_new_used_rebuilt.html 


lunar_c - March 9th, 2014 at 05:20 PM

Thank you very much for your help! Great post. I'm not new to cars by any means but I am new to aircooled volksy's.. The engine strip down was an eye opener. And the machining bill!

If I post a picture of my cooling shroud innards would you mind telling me if everything that's meant to be there? I thought there was meant to be some vanes that were swung open/closed by the thermostat? I don't have those (or the thermostat) but there are fixed vanes that help direct the flow off the cooling fan.


lunar_c - March 9th, 2014 at 05:21 PM

Ps thanks for the tip on the oil cooler also. Had already planned on one as my old motor was full of sludge.


lunar_c - March 9th, 2014 at 07:33 PM

I'm actually wondering on a related subject if an external cooler would be appropriate for my build, a daily driven super bug .. The motor is a 1600 TP, being rebuilt currently to mostly standard specs, new valves and springs, align bored etc, a mild cam (probably engle w110) empi 34 epc kit for carbs (got them cheap for $250 new so willing to work on the issues) and an empi merged header exhaust .. In Perth, do you think an external cooler is necessary?


Doug Sweetman - March 9th, 2014 at 11:50 PM

I have run a hotter tuned engine than that in Perth as a daily without issues in the past. I did run a deep sump which probably helped a bit with extra oil volume and cooling area, but a little mechanical sympathy helps too.

For info I had an 1835, 8.5:1 comp, 044 heads 37 x 35, HSC #2 cam (approx. equiv to engle 110 ish) and kadrons. Was great fun :)

I seem to recall a mod you can do to mount a type 4 oil cooler in the stock location (they are several rows larger but same basic design) which just involved modifying the doghouse on the back of the shroud. Can anyone else elaborate ?


lunar_c - March 10th, 2014 at 12:13 AM

Thanks for the replies guys.

I just can't wait to stick the engine back in..


modnrod - March 10th, 2014 at 05:12 AM

You can stick a T4 cooler in place with a bit of tin cutting, but the results seem to be they work a bit better on the highway, but possibly worse around town. The difference isn't that great however, putting a smaller fan pulley to speed the fan up a bit (ONLY for a low revving motor) makes a much bigger difference. The venturi ring seems to be the best all round mod.
The stock doghouse cooler works really well for most stuff, the only exceptions being sustained high load and/or very high temps. In 95% of cases you won't need anything more, especially for a mild stocker. If you do a lot of gravel driving it's sometimes good to use an external cooler, but that's due to the thing leaking from the constant vibration mainly, the capacity is fine.
By the sound of your motor, and only as a personal choice, an Engle 110 is a bit big, it will work OK, but it's a bit big. For a weekender though, having a "cammy" note is as good a reason as any to have it in there I rekn!
For your engine specs, with small ICTs/heads/exhaust, I would go for a Norris 352S, a CB 2280 or 2232, or the good old favourite Engle W100, something with a .050" duration around 224-234. You won't notice much outright power difference, maybe a couple of HP over 4500, but under 3000 the part-throttle response and grunt will be MUCH better. You won't measure much on a dyno (and when have you done a dyno pull under 3000?), but on the street the difference is chalk and cheese back-to-back.
If you already have a W110, then use it happily though! :yes:
Cooling tin.......
https://www.google.com.au/search?q=vw+cooling+tin+diagram&tbm=isch&tb...

PS: On these funny little things, ALL the power is in the heads, not the cam. A completely stock 1600 TP, but with mild porting still with stock valves, will pull hard well past 5000, stock heads pant and wheeze over 4000. If your heads are in the shop, at least get a good 3-angle seat as part of even a stock rebuild.


lunar_c - March 10th, 2014 at 08:42 AM

Great advice on cams and heads, and the link in thermostats is a great read, thank you.. I'm awaiting a call about my heads and a final quote on all my machining so I'll try and squeeze for it. To be honest even with the tired engine I was surprised at how well the beetle went.. Pretty torquey old thing, so with a new motor even if it is mostly stock I'm sure my wife and I will be smitten.

It appears from that link that my motor would have run the heads pretty hot as there were no heater boxes and the sleds ran open.. Plus the front tins are totally missing.


lunar_c - March 10th, 2014 at 08:48 AM

Time to get some sheet and get on the press brake ;)


matberry - March 10th, 2014 at 09:45 AM

Definately get all that tin repaired and back where it should be. I'm another that believes in the thermo flaps improve cooling even just as a static vane set-up. Because they are hard to find, I copy the og dimensions but in a fabricated design. Have a look in my build thread of Bluey, 130rwhp and 90-100 degrees oil temp. Pics of the vanes about 1/2 way down this page http://forums.aussieveedubbers.com/viewtopic.php?tid=91358&page=19 


lunar_c - March 10th, 2014 at 01:00 PM

You guys are awesome.. This is much appreciated. I'll get to work on fab'ing up those vanes and seal off my sled plates with some heater boxes if I can find them cheaply enough or make up some "industrial plates" like the first link shows.

Those pics are invaluable thanks!


sander288 - March 10th, 2014 at 07:43 PM

You can buy flaps from the us these guys seem to be the best, but if your having static vanes matts idea is ideal.

http://www.awesomepowdercoat.com/thermostat_flaps.html 


lunar_c - March 10th, 2014 at 10:02 PM

Yeah I had my fan shroud on the work bench and drew up a little diagram of a set of bolt in vanes using the linkage holes for fixing them in copying matts fixed vane design.. I'll have to get some sheet and tack it up on my next days off.

Once again many thanks for you guys sharing your expertise!