Post by commercialair on Dec 6, 2006 15:40:41 GMT -5
Well, it's been sort of quite around here the last few days. Christmas parties, shopping, and the winter blues seem to be getting the best of our members. So, here is my first contribution to the Virtual Garage.
I intend this to be a "how-to build a performance 36 hp engine". Anyone that has tried, has probably found a serious lack of quality info on the subject. Maybe it's because no one wants a 36 hp engine anymore?? Maybe it's because it's become very hard to find new parts and the ones available are expensive?? Maybe the draw to higher horse power 1600 dp engines is just too strong?? For whatever the reason information is scarce and a proper list of vendors for the early stuff is nonexistent. I hope to help those people still holding out ,those that just like the idea of keeping there project stock, or even people that just wonder what the differences are between a 1600 and a 36.
Now, I guess I need to lay out my engine plan and give you some background....
This summer we took a try at "racing" the kombi. I put "racing" in quotation marks because anyone that's actually driven an old bus will know that 36 horses of screaming German thunder isn't all that it's cracked up to be. We had a few small technical difficulties and managed to just slide under the 30 second mark for the 1/4 mile. All and all pretty respectable for an old bus powered by an old mill transfered to the track through an old transmission. However, it got me thinking. Was there a way to keep the originality of the '56 and better our time?? I guessed that a stock 36 with proper compression would help. Maybe I could dig up a few vintage speed parts that would buy us some ponies?? Then it happened.... I started to research. I found lots of information relating to 36 hp mods and tuning. Of course, most of it was vague, out dated, and rather theoretical. Still the idea was there and it was apparent that there were thousands of people before me with the same idea. It was possible and it became a challenge.
Background aside, here's my plan. I hope to build a 36 hp based performance engine using old ideas and new. I intend to keep as many stock components as possible and keep the engine both reliable and long lasting. I also want the finished product to appear as though it was built in the 50's. I guess I would like it to be "commercial style performance". Something more fitting to the kombi than a Judson supercharger or a full blown Okrasa machine.
Here is the current build sheet (and it will change as I go):
'61 case -align bored, machined for cam bearings, full flow drilling by Rick Herity(Edmonton). Case chosen for stronger webbing in the later style.
70 or 72 mm stroker crank -standard OG crank welded, stroked, and balanced by Demello machine(California). The final product will be a full race, counterweighted, circle crank. Stock weight flywheel. Sprung performance clutch disk. Stock pressure plate.
Stock over size bearings -getting hard to find, but still not impossible.
Cam bearings -not sure yet?? The 36 hp cams ride on the case halves without bearings. I'm searching for bearings that will work. Machining by Rick Herity(Edmonton)
Cam and gear -stock billet, reground by Aircooled Research(California). 270 X .324. Modified gear with machined groove for better oiling. I still may go with straight cuts??
Rods -stock, machined, re-bushed, and balanced by Reliable machine(Regina).
Pistons and cylinders -still working that out. Probably stock size KS. Overbore 36 pistons are nearly impossible to find. I'm learning as much as I can about friction and heat coatings to use as well.
Push rods and tubes -stock, lengthened for proper geometry.
Heads -stock, ported and polished with 3 angle valve job by Darren Krewenchuk(Vancouver). All NOS valves, springs, retainers and keepers. Springs shimmed for higher revs and less valve float.
Intake -re-jetted, dual 28 PCI carbs on Rethwish aluminum manifolds. Modified Berg linkage and custom made dual choke cables. Manifolds match ported. Velocity stacks, matching air filters, and fuel filters by Aircooled Research(California). Stock fuel pump and lines.
Ignition -Judson CDI coil, stock early bus distributor(non vacuum).
Exhaust - Abarth style 4-tip.
Cooling and oiling -stock tin, powder coated. 40 hp style fan. Fram canister oil filter with braided lines. Okrasa style oil cooler coil behind fan shroud. 356 oil cooler. 21mm pump. Berg deep sump.
That's the basics. Things will change.
In the end I hope for 60 hp with a lot more torque and it's a ton of work for it. Also, it's going to take time. Hunting for parts and waiting on machining and balancing will probably take until next summer. When you build one of these, patience seems to be crucial. You can't just phone up anyone and order the parts. I think it will be worth it in the end.
I will include as many pics of the process as I can. I will also put together a list of vendors and resources for those people looking for parts and info.
So, that it....all that's left is the rest! ;D
Chris
I intend this to be a "how-to build a performance 36 hp engine". Anyone that has tried, has probably found a serious lack of quality info on the subject. Maybe it's because no one wants a 36 hp engine anymore?? Maybe it's because it's become very hard to find new parts and the ones available are expensive?? Maybe the draw to higher horse power 1600 dp engines is just too strong?? For whatever the reason information is scarce and a proper list of vendors for the early stuff is nonexistent. I hope to help those people still holding out ,those that just like the idea of keeping there project stock, or even people that just wonder what the differences are between a 1600 and a 36.
Now, I guess I need to lay out my engine plan and give you some background....
This summer we took a try at "racing" the kombi. I put "racing" in quotation marks because anyone that's actually driven an old bus will know that 36 horses of screaming German thunder isn't all that it's cracked up to be. We had a few small technical difficulties and managed to just slide under the 30 second mark for the 1/4 mile. All and all pretty respectable for an old bus powered by an old mill transfered to the track through an old transmission. However, it got me thinking. Was there a way to keep the originality of the '56 and better our time?? I guessed that a stock 36 with proper compression would help. Maybe I could dig up a few vintage speed parts that would buy us some ponies?? Then it happened.... I started to research. I found lots of information relating to 36 hp mods and tuning. Of course, most of it was vague, out dated, and rather theoretical. Still the idea was there and it was apparent that there were thousands of people before me with the same idea. It was possible and it became a challenge.
Background aside, here's my plan. I hope to build a 36 hp based performance engine using old ideas and new. I intend to keep as many stock components as possible and keep the engine both reliable and long lasting. I also want the finished product to appear as though it was built in the 50's. I guess I would like it to be "commercial style performance". Something more fitting to the kombi than a Judson supercharger or a full blown Okrasa machine.
Here is the current build sheet (and it will change as I go):
'61 case -align bored, machined for cam bearings, full flow drilling by Rick Herity(Edmonton). Case chosen for stronger webbing in the later style.
70 or 72 mm stroker crank -standard OG crank welded, stroked, and balanced by Demello machine(California). The final product will be a full race, counterweighted, circle crank. Stock weight flywheel. Sprung performance clutch disk. Stock pressure plate.
Stock over size bearings -getting hard to find, but still not impossible.
Cam bearings -not sure yet?? The 36 hp cams ride on the case halves without bearings. I'm searching for bearings that will work. Machining by Rick Herity(Edmonton)
Cam and gear -stock billet, reground by Aircooled Research(California). 270 X .324. Modified gear with machined groove for better oiling. I still may go with straight cuts??
Rods -stock, machined, re-bushed, and balanced by Reliable machine(Regina).
Pistons and cylinders -still working that out. Probably stock size KS. Overbore 36 pistons are nearly impossible to find. I'm learning as much as I can about friction and heat coatings to use as well.
Push rods and tubes -stock, lengthened for proper geometry.
Heads -stock, ported and polished with 3 angle valve job by Darren Krewenchuk(Vancouver). All NOS valves, springs, retainers and keepers. Springs shimmed for higher revs and less valve float.
Intake -re-jetted, dual 28 PCI carbs on Rethwish aluminum manifolds. Modified Berg linkage and custom made dual choke cables. Manifolds match ported. Velocity stacks, matching air filters, and fuel filters by Aircooled Research(California). Stock fuel pump and lines.
Ignition -Judson CDI coil, stock early bus distributor(non vacuum).
Exhaust - Abarth style 4-tip.
Cooling and oiling -stock tin, powder coated. 40 hp style fan. Fram canister oil filter with braided lines. Okrasa style oil cooler coil behind fan shroud. 356 oil cooler. 21mm pump. Berg deep sump.
That's the basics. Things will change.
In the end I hope for 60 hp with a lot more torque and it's a ton of work for it. Also, it's going to take time. Hunting for parts and waiting on machining and balancing will probably take until next summer. When you build one of these, patience seems to be crucial. You can't just phone up anyone and order the parts. I think it will be worth it in the end.
I will include as many pics of the process as I can. I will also put together a list of vendors and resources for those people looking for parts and info.
So, that it....all that's left is the rest! ;D
Chris
but haven't..... 
, is find an old stock dual manifold set for 2 28 PICs to finish it off. More focused on the Westfalia collection in the last number of years I guess....
