Help me spec and build a motor for my '70 Bus

[novek]

My '70 pop top Westfalia has been with me about 25 years. I've only ever ran stock 1600DP motors. Early on it was my daily driver, I was young and broke and motors were cobbled together with whatever used parts I could get my hands on. I've got a sizable stash of stock stuff in various states of worn out.

I have a long block that I'm going to build. A few years back I started buying parts for this (was going to be a 1776) but it never happened, I got distracted with buying a new house.

So, let's build this now. Looking for some help in picking parts, and then I'll turn this thread into a build thread. I've lurked on thesamba and used the classifieds since it took over for the old usenet days (damn getting old) but this will probably be my first 'build thread'.

Parts I have and would like to use (all new besides the case):

Universal full-flowed case that was cut for 94mm cylinders
Gene burg full flow oil pump/cover
1 1/2" heater boxes
Vintage speed sport muffler with preheat (supposedly good for 125hp)
SVDA distributor
32/36 Weber and Aircooled.net intake (setup by Jim for a 1776 w/ big valve heads) Planned on using stock aircleaner with preheat, etc.
Doghouse oil cooler
mechanical fuel pump

Things I can't decide on:
Camshaft and compression for a heavy bus in very hot central CA temps
Crankshaft (use one of the stock ones I have or buy a counterweighted stroker crank)
Heads and valve size
Auxiliary oil cooling (I have a deep sump and/or use a remote aux cooler)?

Accessories and other details:
Will use full german doghouse tin, I have an extra set
Leaning toward 92mm thick wall cylinders, probably AA with some better rings
I know lots of people hate the weber 32/36. I've read the very long thread by Jim. I didn't want to cut the air cleaner stand off, and I like that it's easy to pull the engine out.

Goals:
Driving up grades into the mountains when the temp is north of 100 and the bus is loaded down. I want cool running more than power.
I'm ok with spending money, but would like to use the stuff I have as much as possible and also do want to keep costs 'under control'.

I'm sure I'll ask a lot of questions that you've answered a million times, but I do love the forums and want to be a better part of the scene and not just a lurker. Thanks guys, this will be fun!

[madmike]

If it wasn't for that POS carb u insist on using
yes on the TW92's they make ones that fit the case cut for 94mm
78mm crank I have a 82mm in my 70 bus
w110 cam worx great in a heavy bus
I luv my 40 IDF's
yes on the aux oil cooler & deep sump you're gonna need it
I ported some 'stock' heads on my 2110cc bus they work great, bus stops pulling at about 100 mph hills are no problem half the time I don't even 'downshift'
_________________
'Black Ice'Drag Buggy 'Turbo'
Rail Buggy 1915 turbo
76 Drag/Street bug 2180cc 'Turbo' 11:85 @113 mph"If I go any faster I'll burn up the Hamster" ,gets 28 mpg. also 10/09/22 11.90 @115 mph
"If I'm ever on Life Support,UNPLUG Me, Then Plug me back In see if that Works"

[ccowx]

I am actually in the process of doing an engine for my 1970 pop top Westfalia too. Like you, I have gone through a series of daily driven DP 1600's and a few mildly modified engines, and am now looking at building a final engine for it. I also don't want to remove the air cleaner stand and with my location, the heater has to stay also. At least if I want my wife to!!

Here are my goals:

-Keep air cleaner stand and gas heater
-Generally "stockish" or "period correct" appearance.
-Increased hp with good mid range torque and able to cruise at 65 mph.
-Reliable with reasonable mileage
-Must cold start well and run cool in the heat
-Effective heater boxes, both for heat and defrost purposes

My build is going to be a 1968 as follows:

-AE case
-92mm TW with better riings
-74mm stroker crank
-8.5 to maybe 8.8 compression
-worked on DP end castings
-ACN SS intake
-34-3 carb with 28.5mm venturi
-Eagle 2239 cam, HD springs and solid rocker shafts
-ACN L3 heads
-Stock heater boxes (again, the wife, I need good original style heat)
-1-3/8" header, with full cross flow manifold heat
-Gutted oil bath air cleaner
-Original Bosch distributor SVDA and Winterburn CDI ignition
-German cooling tin, dog house etc.
-Stock flywheel, modified for 8-pin crank

Other things I am considering:

-37mm intake valves with 1.25 intake rockers
-37mm throttle bore 34-3 carb with 30mm venturi and modified SS intake.

I will admit, I have not run this yet, but it is based upon years of my own experience with lesser mods and a lot of collective wisdom here. I leaned heavily on Alstrup due to his being in Europe where they have to work with stock appearing components. I am hopeful of getting 90+ hp out of it, maybe even 100 if I am more talented than my usual. Having spent a lot of time driving with 60 hp or so, I am expecting it to have noticeably more power. Being a properly planned build, rather than the cobbled together messes of my youth, I am looking forward to seeing how it feels as much as the extra power.

I think cooling should not be a problem, if things are done carefully. I think proper attention to assembly and you should be fine. I have run a properly assembled engine in central British Columbia at 44 celsius (110 F?) and survived, in the mountains at 2000' of elevation and been ok. I recall the most I hit was 245 F, though it was liking hitting the down hills to cool down! I did experience vapour lock at one point, but that was due to being stuck behind a slow truck at 3500' of elevation in 100+F on a hill.

Carbs are a matter of opinion around here. My main suggestion is to make sure you have correct manifold heat to a center mount. I am not just parrotting what I see here, I have driven a non heated carb in a wet coastal environment just up the coast from you for years, and I won't any more! You may also experience some cooler weather in the mountains and that also is not fun without it.

I am looking forward to seeing this thread too!

Chris

[Alstrup]

Mike, just because YOU can´t figure out how to make the progressive work well is not synonym with them being POS. It may be your personal opinion, but still.

Based on reports from people running thse types of engines, the 1955/2020 is the one that gets the most credit and the 2007/2070 cc ditto for really heavy vehichles.
If you are in the market for a new crank that is what I would recommend. With the 2020 displacement you would want a 37,5 mm intake in a set of AA500 heads. In sunny CA I would think something like 8,6 8,7 CR. along with a CB 2239 cam. You can also choose a set of Panchito´s. That - will - cost you a little lower end torque, but when you get into the midrange´n up you wohnt have any significant difference.
Agree on the sump and aux cooler.
As menthioned many times before, if you want to use the stock bus air cleaner you need to gut it and make it flow enough to handle the extra power.

Done right you will have yourselt a nice easygoing 100ish hp engine.
_________________
https://www.thesamba.com/vw/forum/viewtopic.php?t=435993

[ozzo]

I have 90.5 aa piston, 76 cw crank, aa ss valve 35& 32, 4in1 bugpack. Stock carb 27.5mm vent, stock cam with 1.4 rocker, no ext cooler but i run un natural gas and oil goes in pressure drop.... drive as normal car... if i instal weber progressive give nice additional oooommp...i like tractor power as i run a very long DK gearbox from a t3... with such higher speed you need also to lower the bus.
Just weighted and my t2 is 2 ton... tank to many kg of soud deandening, so it is heavier than a westy...
Go 76 crank... or u ll regret... i m considering what alsrup said at next rebuilt... expecially 37 valve
Ciao

[halfassleatherworks]

for your so called POS carburetor read up here.


https://www.aircooled.net/making-weber-progressive-dfev-work-aircooled-vw-engine/
_________________
Halfass Leatherworks*****GOT LEATHER Made to order Leather crafts, you can find us on that face book thing

Belts, wallets, mouse pads, drink coasters, Engraving, most things made in leather.

personal items if you want it in leather in Reno Nv, *****

[madmike]

nothing but an old 'Pinto' carb that absolutely needs Heat to work
truth be told I've never seen one run good,(some thought it ran good) just talked guys into IDF's and then they 'thanked me' later
_________________
'Black Ice'Drag Buggy 'Turbo'
Rail Buggy 1915 turbo
76 Drag/Street bug 2180cc 'Turbo' 11:85 @113 mph"If I go any faster I'll burn up the Hamster" ,gets 28 mpg. also 10/09/22 11.90 @115 mph
"If I'm ever on Life Support,UNPLUG Me, Then Plug me back In see if that Works"

[nsracing]

I love Kadrons on bus engines. 78 x 90.5mm or 88mm thickwalls. 40 x 35.5 will be good heads. Mild cam or even stock will work good.

Keep it simple.

[oprn]

[madmike]

pureist
_________________
'Black Ice'Drag Buggy 'Turbo'
Rail Buggy 1915 turbo
76 Drag/Street bug 2180cc 'Turbo' 11:85 @113 mph"If I go any faster I'll burn up the Hamster" ,gets 28 mpg. also 10/09/22 11.90 @115 mph
"If I'm ever on Life Support,UNPLUG Me, Then Plug me back In see if that Works"

[oprn]

If I were building a type 1 Bus engine I would go single carb, single port, a hair dryer at 10 psi but that's just me...
_________________
We had the stone age, the bronze age, the industrial age and now we are in the age of mass deception and mind control for corporate profit. (The mass media age)

[novek]

Some great replies here!

ccowx: We seem to be after very similar goals, though I don't run my bus in the extreme cold like you. Early on I used to do a lot of winter camping in the mountains, but I'm getting soft. Are you using stock heater boxes? I have a set of the 1 1/2" boxes which I understand just have a J-tube inside, not the stock finned heat exchanger. I figure'd that would be enough to keep the windshield clear in mild California weather.

Alstrup: Sounds like you've done these kinds of builds too. I'm kind of leaning toward either 92x74 or 92x76. I've never built anything besides stock 1600DP motors. So no experience with setting deck height and dealing with motors that are wider than stock, etc. Lots more reading to do. Appreciate the advice on camshafts, heads, and compression. That sounds like a good combo.

100ish hp sounds great.

With respect to the carburetors, and the stock air cleaner pedestal. I'm not exactly a purist, but I don't want to cut this bus. It's pretty clean and original, and it's made it this far that way. I've read [email protected]'s extensive comments on the 32/36 and think I'll give it a shot.

This will probably be a relatively slow motion thread. Lot's of reading to do about engine widths, etc.

[novek]

Looking for threads on gutted oil bath air cleaners.

Has anyone run a '73 Bug paper filter air cleaner in a bus? How do those flow?

[ozzo]

I do use stock paper air filter... with pict 34 is ok

[vwracerdave]

For a Bus with the 1 1/2" heater boxes and a 32/36 carb limit I would build the 74X92=1968, 5.325 rods, CB 044 CNC round port Magnum heads, FK-65 with 1.4 rockers, 8.3-8.5 CR, stock flywheel. That could get your 100 HP goal.

With the stock dog house fan shroud you should not need an auxillary oil cooler.
_________________
2017 Street Comp Champion - Thunder Valley Raceway Park - Noble, OK
2010 Sportsman ET Champion - Mid-America Dragway - Arkansas City, KS
1997 Sportsman ET Champion - Thunder Valley Raceway Park - Noble ,OK

[madmike]

if he's gonna drive above 55 mph it will need the aux oil cooler
_________________
'Black Ice'Drag Buggy 'Turbo'
Rail Buggy 1915 turbo
76 Drag/Street bug 2180cc 'Turbo' 11:85 @113 mph"If I go any faster I'll burn up the Hamster" ,gets 28 mpg. also 10/09/22 11.90 @115 mph
"If I'm ever on Life Support,UNPLUG Me, Then Plug me back In see if that Works"

[Mark Evans]

[Brian_e]