Bus motor advice

[baz]

I want to put a nice engine together for my dad's 71 westy, somewhere about 2000cc. The ideal engine should give great mpg and be reliable and low maintenance.

It needs to have heat from stock heat exchangers, so I'm pretty sure I want to use steve tims super stock heads with 37 and 32mm valves.

I want to use 90.5 barrels and pistons.

I'd like either a 78 or 82mm crank so either 2007 or 2110cc.

I'd appreciate any input on which crank and rod combo would go together best along with which pistons a or b stroke.

What cam and carbs would be best?  Would 36 dells or webbers be right on something like this or would 40s work best?

I'm gonna put this together myself as a learning experience and so I can borrow my dads bus for a trip to sweden

[nicolas]

i have good results with the use of B pistons on a 78 crank. i did a resurface on the case to lower the deck. and for a bus i would use a W110 cam, it may depend on the carbs, but IDF's (36's or 40's) would work great in my opinion, kadrons can work as well and DCNF's always do the trick for me. the 36 dellorto's will work for sure, again from my personal experience dellorto's can be run smoother compared to IDF's (there is nothing wrong with IDF's)

[dames]

What exhaust would you use on that motor Nicolas? I have a second hand motor with this spec waiting to go into my bus. The guy I got it from said he felt the vintage speed that's on it was a bit restrictive.

[Zach Gomulka]

Factory heat exchangers are very restrictive. Not a good idea to pair them with an engine that large.

[nicolas]

i believe there are options to fit a larger exhaust with heater system these days (CSP comes to mind). but with these heads i would suggest anything from a 1 3/8 or 1 11/2 maximum. honestly i am still figuring out exhausts as diameter isn't the only factor to consider, the vintage speed was used by Beetlebug with good results, ask him or he can shime in with actual real-life knowledge.
i do believe that if you use a conservative CR, good carburation that is set up correctly, bigger cc engines (with heater) can work OK in a bus.

also ask the guys with the SCC bus, they log some miles and have a near 2liter engine.

[baz]

Thanks for the replies. On the subject of stock heaters being too restrictive, I was thinking by using standard size exhaust valves that it would be ok?  I'm guessing the cc does have an effect too. I'm all ears for learning why that is.

[Torben Alstrup]

Hello.
We have discussed this earlier in some other threads.
Stock heater boxes are good to about 110 hp and 120 if you push it. So 110 is reasonable.
36 Dells have about the same performance range, so that computes OK.
Super stock heads would be a good choice for such an engine.
Personally I would not build it above 2 liter with the parts in mind. When you hit about 1900cc displacement the carbs actually begins to limit the intake, so there is vacum in the intake port at WOT (if the engine is efficient), so that the engine does not pull more torque eventhough you floor it. My choice would be 1955 or 2007 at the most. My cam choice would be the Web 218, because that cam makes a wider torque plateau, which is what you want in a bus. The W110 would pull higher hp numbers, but loose in the lower rpm range.

I have had a few customers that ran 2110 bus engines with 36 Dells. On one of them I recently made some heavy modifications to the carbs to see if I could make them flow better and release more usable power from them. I actually managed to improve them 7 CFM @ 25" over stock. The engine definitely became more responsive in the midrange, but I have not had it on the dyno yet, so I do not know for sure how it actually performs. - But even if it should actually pull 6-7 hp more I would say that the modification is not really defendable financially over swopping to a set of 40´s because the mods take a full day to perform. I did it because the guy, - and myself too, wanted to see how much we could improve the carbs and the performance of the engine.

T

[baz]

Thanks Torben, I think I understand that a 2000cc + size engine is in effect too much of a pump for the stock heads and 36 carbs?  Or am I missing another factor?

I've looked at the web 218 and see it's recommended to use dual springs,  is this something I need to do on an engine that won't see beyond 5.5k rpm?

[Torben Alstrup]

Especially with stock valves there is no need for dual springs with the 218. - With stock valves, Scat HS springs, aluminum push rods and Ti retainers it´ll rev to 7000 clean. About 6300 is safe even with normal valvetrain and 40 x 35 mm valves.

T

[Bryan67]

When I had my 68 Camper I ran a 2276cc mild motor. 37x40 valve round port 044 heads, 110 cam, 82 crank, 94 Pistons, 5.5 H beam rods, about 8 to 1 compression, 40 Dells, full flow with a remote cooler and fan, A1 1.5" sidewinder and heater boxes. This combined with a built trans using a 4.57 ring and pinion and lowered with 185/65x15 tires on the back led to 70 mph cruising speed, cool and smooth reliable running on a 20 minute freeway commute in 100 plus temperatures with no problems at all.

[cedric]

My bay westy,2110cc alu case,w100,8-1comp,40 mm weber,cb 044 heads,091 gearbox,stock heatherbox and vintagespeed exhaust....good torq en fun to drive,no cooling issues..driven now for 9000km with now problems and 11l/100km fuel use,we drive 100km/u on freeway

[baz]

When I had my 68 Camper I ran a 2276cc mild motor. 37x40 valve round port 044 heads, 110 cam, 82 crank, 94 Pistons, 5.5 H beam rods, about 8 to 1 compression, 40 Dells, full flow with a remote cooler and fan, A1 1.5" sidewinder and heater boxes. This combined with a built trans using a 4.57 ring and pinion and lowered with 185/65x15 tires on the back led to 70 mph cruising speed, cool and smooth reliable running on a 20 minute freeway commute in 100 plus temperatures with no problems at all.

Nice bus and engine

Are they bigger than stock heater boxes? 

[baz]

My bay westy,2110cc alu case,w100,8-1comp,40 mm weber,cb 044 heads,091 gearbox,stock heatherbox and vintagespeed exhaust....good torq en fun to drive,no cooling issues..driven now for 9000km with now problems and 11l/100km fuel use,we drive 100km/u on freeway

That sounds like a great package, what size valves are in those  044s?

[Martin S.]

I was planning a torquer stock-looking good economy bus motor using the small-bore long-stroke gets good mileage theory (see BMW and Hondas). To do that we planned to use Air-cooled.net's stroker 85.5 piston/cylinder kit and 84 mm crank and 5.7" rods. (low deck height, high squish, high CR of course) The engine would be wider than stock but it would be worth it because the fuel economy would be amazing! John at Air-cooled.net seems to agree with some of his copy in this 'VW Type 1 Mileage Master MPG Engine Combo' article... http://www.aircooled.net/vw-type-1-mileage-engine-mpg/

[Bryan67]

Yes, 1.5" heater boxes.

[Torben Alstrup]

When I had my 68 Camper I ran a 2276cc mild motor. 37x40 valve round port 044 heads, 110 cam, 82 crank, 94 Pistons, 5.5 H beam rods, about 8 to 1 compression, 40 Dells, full flow with a remote cooler and fan, A1 1.5" sidewinder and heater boxes. This combined with a built trans using a 4.57 ring and pinion and lowered with 185/65x15 tires on the back led to 70 mph cruising speed, cool and smooth reliable running on a 20 minute freeway commute in 100 plus temperatures with no problems at all.

20 minutes on the freeway (!) I´m thinking more like 20 hours. I will admit though that a 100 degree F. ambient is a killer

T

[Phil West]

I used a 76mm crank to help keep the motor that much narrower for a slightly easier fit in the engine bay.  Worth considering.

[baz]

I think I'm pretty set on a 78mm crank with b pistons,  whether i deck the case or run 5.5 rods hasn't been decided. Decking the case will give a narrower than stock engine if my sums are right,  using 5.5 rods and spacers will only be a few mm wider than stock,  again depending on if my sums are right.

[Martin S.]

Everyone seems really concerned about their engine width. Is it really a big problem in a van? My 2332 was a good half inch wider each side, so much we had to widen the main shroud to extend out to the edge of the top cylinder tin without leaving a gap, and the engine still fit in my 68 bug without mods to the engine bay.

[baz]

Are there issues fitting a 4 into 1 header if the engine is much wider than stock?

[Zach Gomulka]

Are there issues fitting a 4 into 1 header if the engine is much wider than stock?

A standard header, yes. A merged header, no.

How about thick wall 92's, 74mm crank, 5.325" rods, 1968cc. Comes out only a hair wider than stock.

[baz]

I'll be using a standard header. Do the thick wall 92s use the same spigot size in the case and heads as 94mm? 
Any reason for using the above combo over a 78mm with b pistons other than removing the necessity to deck the case?
Thick walls may be difficult for me to get hold of, I have a set of mahle 94 stroker barrels and pistons I was hoping to trade for a set of 90.5s.

Do all new cases require decking to equal crank centre line?  If so then it's not a lot extra work to have the deck on both case halves reduced to suit the 78 crank b spec pistons combo.

[Bryan67]

Width was never an issue for me. And use the 94`s. They will be fine.

[Jim Ratto]

In the late 1990's I built a daily driven 90.5 x 78 that went over 150,000 miles with only a clutch replacement.

I would suggest something similar to this, keeping in mind cooling, and ease on valvetrain, but enough "cam" to facilitate cooling and good VE/torque

new VW case
Welded 78mm, VW journal, from non-cross-drilled core
Stock rebuilt VW rods
7.5-7.8:1
Stock original VW heads, ported like Bill Fisher book specifies, TRW valves. If you can, have heads modified for 14mm x 3/4" or even better 12mm x 3/4" plug threads (for longer life)
For the cam, I would consider Engle V26 or FK7, as both are very mild profiles at the lobe, and use 1.4 rockers. The lift you'll get with ratio rockers may seem to be overkill for stock valves, but there's reasons why this "works"
Good dual valve spring, make sure they will accommodate lift of cam/rocker combination and make sure the inner and outer springs "rub"
grind keepers so they do not touch in situ
Need to do some math on appropriate exhaust size. It will depend on camshaft. Don't "skimp" on what you do about exhaust, as wrong choice will "bake" your motor to a gold crisp.
Stock VW 1971- shroud and real VW cylinder covers with air dams shaped like "/\" above intake area. Stock pulley, good OEM B fan
Full flow with filter of your choice and a good Setrab cooler if it's HOT where this will get driven.
And I would suggest 44IDF Weber for this size engine.

Have fun

[Jim Ratto]

BTW, a 78mm crank with stock rods and "B" pistons goes together like a stock motor. If you have to use shims under cylinders, it will be minimal. The engine sheet metal will drop on like a stock motor.

[Martin S.]

I wouldn't go back to the medium compression in the 7 to 8 range now that I've driven a high CR stock-ish engine. Even if it lasted twice as long at low CR, high CR is just that much better! 

[DWL_Puavo]

My "recipe" can be found here http://cal-look.no/lounge/index.php?topic=24597.0 and it's quite similar that has been suggested in this thread already. Basicly 76 stroke, 90,5 "b-pistons", case decked a bit, mild cam, mildly ported stock heads with heater boxes and simple 4-1 exhaust. Now just waiting for the rest of the snow melt to fire it up again

*EDIT: My engine was with 76mm stroke (not 78mm as I wrote before) and it was a bit problematic being maybe just a tad too narrow, but nothing serious. With 78mm stroke it should be a little bit easier. Also, snow has been melting quite fine this week.

[baz]

Thanks for all the suggestions, it's pretty much nailed on then at 2007 in my mind,  few different cam suggestions to look at over the coming months as I gather all the parts together.

[baz]

I've been looking at some tools for checking all the necessary measurements involved in blueprinting an engine. Prices vary wildly from different manufacturers,  I spotted this internal micrometer set on ebay and was hoping someone may be able to tell me whether it's worth buying or best avoided?

http://m.ebay.co.uk/itm/Mitutoyo-511-712-Dial-Bore-Gauge-1-35-60-mm-0-01mm-Brand-New-and-Original-/261862162340?nav=SEARCH

[brian e]

I've been looking at some tools for checking all the necessary measurements involved in blueprinting an engine. Prices vary wildly from different manufacturers,  I spotted this internal micrometer set on ebay and was hoping someone may be able to tell me whether it's worth buying or best avoided?

http://m.ebay.co.uk/itm/Mitutoyo-511-712-Dial-Bore-Gauge-1-35-60-mm-0-01mm-Brand-New-and-Original-/261862162340?nav=SEARCH

That is a bore gauge and it is what you need, but you will also need a set of outside micrometers to go with it.  You will measure the crank journal with the outside mic, and then use the mic to set up the bore gauge and zero it.  Once the inside bore gauge is set, you use it to measure the clearance between the journal and the inside of your bearing.

Just the bore gauge alone wont get you and numbers. 

Brian