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Post by CrazyBrit on Jan 29, 2021 20:56:44 GMT -8
I am slowly beavering away at my bus, but thought that I should ask the engine questions here. This is the 1914 that I had in the bus a few years ago. Those that "enjoyed" the ride back from Volksfest with me a few years ago may recall that it appeared to be running rather hot. Although it was definitely warm that day, it did not achieve the temperatures that I initially thought - I later discovered that my temperature gauge was reading around 40 degrees over actual at 100C when tested in boiling water. The gauge reached 250 - 260 F that day, but I think it was actually in the low 200s, which is perfectly acceptable. The ambient outside temperature was around 35C that day.
The engine was a 100% new 1914cc Scat longblock, built from a brand new AS41 case. It is fitted with a Scat C25 camshaft and 40 x 35.5 heads. The carbs are 2007 Weber 40mm (Made in Spain I think). It was running an early 2000's Bosch 009 with Pertronix Ignitor ignition and the stainless exhaust from my 1600cc motor, which proved too restrictive. It leaked oil, possibly due to no crankcase breather as I am now learning. To date, the engine has around 400 - 500 km on it, so is essentially new, although it is now 14 years old.
I have removed the heads and fitted new stainless steel windage pushrod tubes to fix the oil leaks. I am now reassembling it with all OG tinware (thanks Reagh!)
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Post by CrazyBrit on Jan 29, 2021 20:57:58 GMT -8
So, with the intro done, the first question. I am planning on buying a Vintage Speed exhaust system for this engine. Can I get away with the stock VW heat exchangers, or do I need to upgrade to either J-tubes or higher flow aftermarket heaters without the fins?
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Post by owdlvr on Jan 29, 2021 21:15:29 GMT -8
I would suggest you want J-Tubes or the high-flow aftermarket heater boxes.
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Post by 1hotvw on Jan 29, 2021 21:24:02 GMT -8
if you dont drive it in the winter you don't need heat, also the vintage speed stuff comes with flanged j-tubes as a set. why spend more on high flow heater boxes. just size your header to your engine size. you only want to order once.
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Post by Volktales on Jan 29, 2021 22:23:23 GMT -8
My Ghia uses the stock generic replacement heaterboxes that have been available forever. They fit just fine with the vintage speed exhaust. But then top performance was not my goal. Those in the know about speed would prefer something that flows better. I value my heat so no J-tubes for me...
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Post by magikbus on Jan 30, 2021 7:47:46 GMT -8
if you dont drive it in the winter you don't need heat, also the vintage speed stuff comes with flanged j-tubes as a set. why spend more on high flow heater boxes. just size your header to your engine size. you only want to order once. Right, heres a challenge for you. Try driving across the country, twice in two successive years with your wife in a Westy with no heat, then tell me if you dont drive it in winter you dont need heat. Stan
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Post by CrazyBrit on Jan 30, 2021 9:35:22 GMT -8
I don't have any current plans to drive across the country in my Split. I also don't have to worry about my wife coming on that journey if I ever do - she would refuse (Not an aircooled VW fan). I haven't driven it in the winter since 2005ish and it's only been out in the rain once since then too - last fall driving up to Funbugz.
It currently has Volvo seats in the front with heater elements, which may end up being connected up if I go down the non-heat route.
I am concerned that running the stock heater boxes will be too restrictive on the two forward cylinders, thereby creating an imbalance in the engine and potential for overheating and increased wear. I'll have to look into the Vintage Speed systems more closely, because I thought that you could buy them without the J tubes and then buy the heaters separately. I read from the above that I should not run the stock heaters though.
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Post by owdlvr on Jan 30, 2021 11:23:41 GMT -8
I can confirm that when you buy a Vintage Speed system, you are buying:
Rear Muffler Cyl 1&2 runner Cyl 3&4 muffler to heaterbox adapter flange.
You can then _add_ to your system very nice J-Tubes (in matching stainless steel) or use whatever else you like. AVR, our most local VS supplier, often brings in systems complete with J-Tubes, so locally they are sometimes sold "complete" with J-Tubes. The imbalance of exhaust pipe size between the 1/2 runners and _stock_ heater boxes is why I suggest J-Tubes or high flow (1.5") heater boxes. If you don't want heat, save your money and go J-Tubes. If you really want to save money, you can use the Empi 1.5" J-Tubes.
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Post by magikbus on Jan 30, 2021 13:59:26 GMT -8
Mark, I have a cylinder head temp gauge for my 2L and although I havent driven it yet I was warned by my engine rebuilder that despite the horrendous cost of the gauge and sender, that they are notorious for being off with no way to adjust them. His advice was not to worry too much about the initial temp reading, just to keep an eye on it for change. If it seemed high, but always was showing high not to worry, only start worrying if it got much higher for no reason etc. etc..
It sounds like yours is a perfect example of that. Stan
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Post by CrazyBrit on Jan 30, 2021 16:13:43 GMT -8
I replaced the original gauge and sender. The new one is accurate at 100C in boiling water. The day the motor got hot I was watching the trend going up quickly as I climbed the Malahat. It was an extremely hot day though, which didn't help. I was not looking at the Superflow VS exhaust system with the header. I was looking at the T2 Sport muffler for up to 125hp motors, without the heat risers. The cost difference is similar to the cost of high flow heat exchangers. Would I notice much real world difference between an equal length system and the regular Sport system, bearing in mind it will be pushing an IRS equipped Split bus? store.concept1.ca/V.S.-Muffler-T2-60-67-Sport-%28VSD15520605200%29-VSD15520605200/
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Post by owdlvr on Jan 30, 2021 17:22:34 GMT -8
Personally I don't think you're going to see enough of a difference with the equal length system.
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Post by Rob Sannes on Jan 31, 2021 20:04:07 GMT -8
Mark I would not run stock heater box's on performance heads. You have a performance motor so J tubes would be my choice. I would match your exhaust size to the exhaust port size likely 1 3/8" or 1 1/2" you might lose a bit down low in the rpm range going to the bigger size. I had lots of gauges in cars in the past but spent more time watching gauges than enjoying my drive. My 56 has a oil light and tach that I can barely see. I do have one of the temp gauges that will make the oil light flicker. Of courses you need all cooling tin in place as well as timing & jetting correct, then you should not have an overheating problem. Now your 40mm IDF carbs if in stock form may need a little work. Stock 40's should work ok but will run out of breath on the top end as they come with 28mm venturis wich are a little small for your valve size. I would bump them up to 32mm vents then jet up a little but that can be done later if you need to buzz it up past 5000rpm on a regular basis.
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Post by Rob Sannes on Jan 31, 2021 20:15:33 GMT -8
if you dont drive it in the winter you don't need heat, also the vintage speed stuff comes with flanged j-tubes as a set. why spend more on high flow heater boxes. just size your header to your engine size. you only want to order once. Right, heres a challenge for you. Try driving across the country, twice in two successive years with your wife in a Westy with no heat, then tell me if you dont drive it in winter you dont need heat. Stan So heat is for girls according to Stan. Honestly I like my ladies a little on the chilly side ( • ) ( • )
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Post by CrazyBrit on Jan 31, 2021 20:43:39 GMT -8
I wasn't planning on 5000RPM. I was looking for an engine with enough guts to push the bus up the hills and keep it at a sensible speed on the highway. It's not really the right shape for racing!
I do have some jets in the garage. What's involved with changing out the venturis?
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Post by Rob Sannes on Jan 31, 2021 20:59:02 GMT -8
Mark with those plans leave them alone. It is not hard change them out, but can be scary the first time. Remove carbs remove tops remove accl pump squirters auxiliary vents, set screws on the side then the venturies will slide out from the top. New ones slide in place reassemble in reverse. Shouldn't change float hight or anything. Will require a bigger main jet and likely smaller air jet. If you get to that point I would be glad to help. Check out Dave's tread where he talks about his carbs you can see the cylinder looking venturies they have a 28 stamped on them.
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