What are the major differences between a real Porshe/VW type-4 and a VW/Bus core? Is one better than the other?
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What are the major differences between a real Porshe/VW type-4 and a VW/Bus core? Is one better than the other?
Off top of my head - the bus has low compression pistons and early ones the dual solex carbs with boss on engine for the mechanical fuel pump. The oil filler set up is different too. Oh and the flywheel - 215mm on 914 and 210 on bus (210 is needed to mate to T1 transmission). The 914 had fuel injection stock in US (carbs overseas) with high pressure electric fuel pump. A T4 bus engine has a lot of weight to push around so for a core could be well worn. The VW 411/412 used same engine too but most were AT. The 411 heat exchangers are good to use - bus if cut down. Came in 1.7, 1.8 and 2L versions at least in 914. 2L has longer stroke crank, bigger pistons and bigger valves.
Great source of info -
http://www.tunacan.net/t4/
I have '75 1.8L 914 T4 sitting in garage --- at bottom of my long to do list. Plan to rebuild stock with the Solex bus carbs - and probably the original flat cooling tin (or the Joe Cali upright conversion).
Ha, I'd say there isn't a real Porsche 914 engine - all VW bits.
Either can work if core in good shape - 2L is most desireable. What's the next project?
Great source of info -
http://www.tunacan.net/t4/
I have '75 1.8L 914 T4 sitting in garage --- at bottom of my long to do list. Plan to rebuild stock with the Solex bus carbs - and probably the original flat cooling tin (or the Joe Cali upright conversion).
Ha, I'd say there isn't a real Porsche 914 engine - all VW bits.
Either can work if core in good shape - 2L is most desireable. What's the next project?
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Marty--do I detect the TYPE IV fever starting? I had it and took the cure.
If you want, email Jake Raby at; jake@aircooledtechnology.com
and he will be happy to set up a time to call and chat with zero obligation. He is the Guru when it comes to Type IVs.
My engine case was sourced from a two liter Porsche 914 --he has a pretty vast selection to choose from.
Scream all you want---no one will hear you!!!!
If you want, email Jake Raby at; jake@aircooledtechnology.com
and he will be happy to set up a time to call and chat with zero obligation. He is the Guru when it comes to Type IVs.
My engine case was sourced from a two liter Porsche 914 --he has a pretty vast selection to choose from.
Scream all you want---no one will hear you!!!!
Marty,
Go for the T-4 but you will always wish you had a couple of extra cylinders...6 cylinders are the only way to go.
Go for the T-4 but you will always wish you had a couple of extra cylinders...6 cylinders are the only way to go.
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Dave, that is car porn.
No kiddin'. I think I need a moment.
Dave, you really have to stop that. There's not enough time in my day to drool over that car of yours for five or six hours AND get meaningful work done on mine, okay?
Marty, what specifics are you after? I can ask a guy here for spec sheets and mail 'em to you, if there are things you're looking to do with an engine for a Speedster.
And, naturally, Jake's a GREAT resource. You'll want to talk to him about cooling, anyway.
Marty, what specifics are you after? I can ask a guy here for spec sheets and mail 'em to you, if there are things you're looking to do with an engine for a Speedster.
And, naturally, Jake's a GREAT resource. You'll want to talk to him about cooling, anyway.
That is the photo of just before we lit it off for the first time. If I could figure out how to post a video I have one running as well.......:-)
Do NOT covet thy neighbor's Speedster ......
wolfgang - just to correct you on the flywheels. the T4 engine-equipped bus came with 210, 215mm and 228mm flywheels - both 210 and 215mm work fine in a T1 trans. the 228mm is large enough that it can be made to work, but requires clearance work on the trans (not worth it).
I'm running a 215mm on my T4 w/T1 trans.
buses also came w/FI (high pressure pump, etc).
The 2L in 914 and buses have a 71mm stroke and a 94mm bore. The rod journals on the crank are smaller on the 2L than the 1.7-1.8L (66mm crank). the 66mm journals are similar size to a T1
the heads on a 914 2L are the major difference between the two.
essentially a 1.7L and 1.8L bus and 914 are very similar while the 2L bus and 914 are quite a bit more different (heads, compression, etc)
I'm running a 215mm on my T4 w/T1 trans.
buses also came w/FI (high pressure pump, etc).
The 2L in 914 and buses have a 71mm stroke and a 94mm bore. The rod journals on the crank are smaller on the 2L than the 1.7-1.8L (66mm crank). the 66mm journals are similar size to a T1
the heads on a 914 2L are the major difference between the two.
essentially a 1.7L and 1.8L bus and 914 are very similar while the 2L bus and 914 are quite a bit more different (heads, compression, etc)
And the eigth deadly sin..........CHILLI!
Isnt the Bus flywheel heavier?
Anyone know the weight diffrence between the 215mm bus and 914 Flywheels pls post
Anyone know the weight diffrence between the 215mm bus and 914 Flywheels pls post
Suspect it is. The 914 flywheel is forged so is stronger - the bus cast so weaker. If you try to use a 228mm or a 914 flywheel you will have to have machining done - the teeth are set differently so they won't mesh properly with T1 starter - also the clutch/press plate is different profile. All will need a T1 main shaft input bearing added. You can have the flywheel lightened and it still is safe for street use.
http://www.tunacan.net/t4/tech/flywheel.htm
http://www.tunacan.net/t4/tech/flywheel.htm
The Bus flywheel is cast and is lighter by 4 pounds than the 914 unit. The 914 unit is NOT compatible with the T1 transaxle in both starter mesh as well as pressure plate/ release bearing compatibility. The proper unit to use is a 200mm conversion flywheel thats forged, can be lightened and accepts the popular Type 1 pressure plates. This is what I outfit my engines with.
The Type 4 conversion is just a big recipe... Everything bolts together with the proper components and component selection is key. Thats where I come in... I know all the interchange off the top of my head and that WILL save you wasted time and extra money.
As far as the "six cylinder" goes.. Well it weighs at least 150 pounds more so those two extra cylinders had better make at least 50HP more each.. Also an extra 150 pounds aft of the rear wheels in a rear engined car is VERY notable in the handling department.
Keep the car lighter and more nimble, use a high torque, lightweight power plant and the car will be more balanced in every way.
The Type 4 conversion is just a big recipe... Everything bolts together with the proper components and component selection is key. Thats where I come in... I know all the interchange off the top of my head and that WILL save you wasted time and extra money.
As far as the "six cylinder" goes.. Well it weighs at least 150 pounds more so those two extra cylinders had better make at least 50HP more each.. Also an extra 150 pounds aft of the rear wheels in a rear engined car is VERY notable in the handling department.
Keep the car lighter and more nimble, use a high torque, lightweight power plant and the car will be more balanced in every way.
Jake,
With the IM-6 its all about where you place the motor. Henry's design is brilliant. I'm not so sure I would convert a 4 cylinder Speedster to 6 cylinders but starting from scratch using the long wheelbase arms from a 911 and moving things three inches forward helps a bunch to offset any weight issues. My 3.0 is 235Hp and 225 ft/lbs torque from a pretty stock motor and is a recipie for long life low maintanance and lots of fun.
Best air cooled 4 cylinder. T-4 hands down. I would not think of anything else.
With the IM-6 its all about where you place the motor. Henry's design is brilliant. I'm not so sure I would convert a 4 cylinder Speedster to 6 cylinders but starting from scratch using the long wheelbase arms from a 911 and moving things three inches forward helps a bunch to offset any weight issues. My 3.0 is 235Hp and 225 ft/lbs torque from a pretty stock motor and is a recipie for long life low maintanance and lots of fun.
Best air cooled 4 cylinder. T-4 hands down. I would not think of anything else.