TheSamba.com :: View topic - how to put a Porsche 914 motor in a bay window bus

Tue Aug 31, 2010 11:34 pm

fusername wrote: i think domed pistons are only avail for a 1.7 motor. all the other 914 versions of the T4 had the exact same CR as the bus versions. the 2.0 914 used a shallower dish because the head has a LARGER chamber, so this kept the CR the same. I ran a even higher CR than stock 914 2.0 in my bus, and only had to pull the engine because of oil pressure, which was an issue prior to me getting my hands on that motor. 8 months and several 10s of thousands of miles later, still alive i think, will tear it down in a few weeks or months and see if there is any damage, but I think it was fine.

also i ran it with larger tires than stock which should hurt torque, but she pulled amazing! compared to any other engine i have ever run in there (stock 2.0 and bus 2.0 with mildly raised CR)
Sooo... What sort of piston did the 1.8 914 use?
You've got me worried here mate. I'm going to dig out my spare barrels and confirm i didn't do a put down and pick same up switch when I changed pistons and barrels a couple of years ago. Surely a 1.8 piston couldn't fit in a 1.7 barrel anyway. Can't hurt to check I guess.

Wed Sep 01, 2010 5:03 am

All the fuel injection stuff will work too ?

Wed Sep 01, 2010 5:40 am

You need to use all of the FI components from the '79, and it should work fine. If the '76 has an ECU (brain) in it, remove that and use the one from the '79.

Wed Sep 01, 2010 5:45 am

The 1.7L head was pretty much made for the domed piston. See that dimple near the quench area? That was made to optimize and steer the mixture pushed up by the dome into the quench area.

They were not really originally made for or envisioned with the 914 in mind. They originally came in the 411/412. Every 411/412 1.7L with fuel injection except for California used the domed piston.

They run very well. Typically about a .080" dome rise on piston...and about .075-.079 deck around the piston edge.
Be careful using these in a bus. 8.2;1 is stock compression....but if you remove the head gasket (about .028") like you should....that reduces deck to about .051". If you remove base gasket and seal....it usually removes another .011"....so .040" deck. This is good for cooler running as it gets the flamefront out of the jug and into the head.......but your static compression goes up to about 8.5 to 8.6 depending on chamber volume and camshaft overlap.
Ray

Wed Sep 01, 2010 7:12 am

Thanks I guess I got some work ahead of me ! Lol

Wed Oct 06, 2010 11:54 pm

Well I'm new to this VW Bus business. I have a '68 VW Transporter Westy. My engine just died. I could rebuild it but I was wondering if the 914 engine would work on mine.

Thu Oct 07, 2010 12:12 am

68greenvw wrote: Well I'm new to this VW Bus business. I have a '68 VW Transporter Westy. My engine just died. I could rebuild it but I was wondering if the 914 engine would work on mine.

If you want bigger HP than a T1 can dependably deliver, probably the cleanest engine swap you could do would be Type 4 VW engine with DTM (down the middle) cooling.

Sat Oct 09, 2010 3:54 pm

hey guys i just wanted to jump right in since you guys seem to have a good grasp on the t4 eng. well......i have a 71 square and i also have a raby built t4 eng with no home(carbs) if i were to put this motor in my square....is there anything i should know before hand? oh and the square is auto

Sat Oct 09, 2010 5:31 pm

Sounds like a question you should be asking Mr. Raby.

Tue Oct 12, 2010 2:56 pm

i was looking for somethin more along the lines of reasons why i shouldnt or what to look for or what needs to be changed. thanx enway tho!

Tue Oct 12, 2010 4:24 pm

you will need some stuby little manifolds, and you will love your new car! go pop on over into the typ4urm over on shoptalkforums.com, they used to have a sticky just for this conversion, but it has since been released into the wild buta quick search should turn it up.

also the stock aircooled vanagon rear engine support works beautifully on the T3 conversion.

err, i mean, its a super hard conversion and you need to sell me the square and the engine. I'll let you keep the auto trans tho.

Wed Oct 13, 2010 5:41 pm

sweet man thanx! thats kinda what i was lookin for! so would the auto trans be an issue u think?

Thu Jul 24, 2014 8:29 am

Sorry for reviving an ancient thread.. but if I can source a 914 engine with these specs to replace the 411 w/injection in my 78 Bus:

1800cc engine out of a 74 Targa Bosch L Jetronics fuel injection,8.6 :1 compression,85 hp

I am looking at
1) dipstick & filler in wrong spot
2) compression ratio wrong/harmfully high -- which can be fixed by using bus pistons?
3) use my fuel injection components from 411

if it is known good for less than a grand vs my 411 may need rebuild... is it a decent option while I take my time rebuilding / selling mine? I know nothing about internals so I would be learning or paying for work to modify the 914.

Thu Jul 24, 2014 10:03 am

Several people have run the higher compression engines successfully. Takes careful tuning and a watchful ear to do so. Yes you will want to run high octane gasoline, but the price difference should be offset by a slight increase in gas mileage. Set your timing at around 26° BTDC at 3500+ rpms hoses off and see how it runs.

Thu Jul 24, 2014 11:46 am

MrBryan wrote: Sorry for reviving an ancient thread.. but if I can source a 914 engine with these specs to replace the 411 w/injection in my 78 Bus:

1800cc engine out of a 74 Targa Bosch L Jetronics fuel injection,8.6 :1 compression,85 hp

I am looking at
1) dipstick & filler in wrong spot
2) compression ratio wrong/harmfully high -- which can be fixed by using bus pistons?
3) use my fuel injection components from 411

if it is known good for less than a grand vs my 411 may need rebuild... is it a decent option while I take my time rebuilding / selling mine? I know nothing about internals so I would be learning or paying for work to modify the 914.

Some bits and pieces here....you still need a little research. The 411 engine...if it has/had D-jet injection.....already has domed pistons and 8.2:1 compression and put out 82hp stock (some sources say 80 but dyno shows a range depending on build quality. I have seen some as high as 85 with great tuning).
If it did not put out a nominal 80hp...then whoever is tuning it does not know what they are doing with D-jet or the engine is worn.

How is going to an 1800 914 an improvement in either performance or head temp safety? The 1800 as you note has even higher compression than the 1.7....and factually the D-jet injected 1.7L (in excellent tune) ran circles around the L-jet inject 1.8L in the 914.

The L-jet has not as good throttle response on the 1.8L. Dont confuse hp with torque and usable power band when leveraged against gear ratios.

Both engines can live well in a bus when properly tuned...or even de-tuned....but what you really need is a type 4 engine in either displacement with the proper cam and compression for a bus to develop torque where a bus needs it...not where a 914 needs it.

Oh...by the way. The 1.7L 411/412 engines are factually 100% identical down to the last part to the 1.7L 914 engine ....same cam part #, valve sizes, piston configuration, compression ratio, windage tray etc. They are built from the same parts on the same assembly line. Same exact engine except for heat exchanger design, sheet metal differences and fan pulley markings.

It just cheeses the Porsche-philes off when you prove that to them.

You already have a Porsche 914 engine in your bus actually.

The one good reason to go to L-jet...even though performance wise D-jet has better response and output ability....is that compared to L-jet....D-jet is very finicky and tedious to tune properly unless you have practice.

Also D-jet makes use of a specific cam profile that while ok for use on carbs as well is really designed for the correct intake valve opening timing for the paired D-jet injection. Its also a hot running (for the heads) compromise of a cam. The web #73 is a very good improvement for the D-jet and still retains early D-jet intake valve timing. The Raby 9550 is an improved version of the Web #73 and even better.

I am pretty sure that the 1800 in 914 used the same cam as D-jet 1.7. the 2.0 was different (Euro version).

There are much better cams available specifically for busses and the torque band you require. Just some thoughts. Ray

Oh...yeah...if you are getting a complete running 1800 with injection and sheet metal etc.....even though that sheet metal will not fit your bus.....if the condition can be proven....that is a good investment while waiting to rebuild your 1.7L properly.
Or......even better, talk the seller down to $800....sell the sheet metal and rebuild the 1.8L while you are driving the 1.7L around. Ray

Thu Jul 24, 2014 2:03 pm

Thanks ray -- sorry where did the D-Jet stuff come in?

The engine says it was L-jet (but has carbs included which I could remove from the price) and I assumed my setup is L-Jet as well..

Mine performed well through all rpms so we can assume it has an appropriate cam... which I could swap in or buy then? or am I only concerned with the cam gear?

I'm tempted to just try it out but if it's not so onerous to put the correct cam and pistons to do it right perhaps that's worthwhile.

p.s can't drive my current engine anymore it is spewing smoke so I'm hoping to do something less involved to get an engine in and then work slowly on the other.

Thu Jul 24, 2014 3:03 pm

MrBryan wrote: Thanks ray -- sorry where did the D-Jet stuff come in?

The engine says it was L-jet (but has carbs included which I could remove from the price) and I assumed my setup is L-Jet as well..

Mine performed well through all rpms so we can assume it has an appropriate cam... which I could swap in or buy then? or am I only concerned with the cam gear?

I'm tempted to just try it out but if it's not so onerous to put the correct cam and pistons to do it right perhaps that's worthwhile.

p.s can't drive my current engine anymore it is spewing smoke so I'm hoping to do something less involved to get an engine in and then work slowly on the other.

You noted that you have an INJECTED 411 motor in your bus. The 411 motor came with D-jet injection...not L-jet.....so therefore do not assume your 411 motor is L-jet. verify it.
L-jet ONLY came in 412 cars...and only with 1.8L engines.

But hey...if what you already have is actually a 412 engine with injection....then what you have is actually lready virtually a bus engine. The 412 with 1.8L L-jet came with about 7.8:1 compression,

So...this 1.8L was/is supposedly a 914 1.L which only came with L-jet in the US...but now has carbs (which to me are worth "0" except what they can be sold for to offset price)

The cam issue has nothing to do with the gear or whether it will run"well" through all rpms.....its about at what temperature the engine is running at when you may be forcing it to make power in a band that is not ideal.

The gears are all the same. Some early type 4 bus engines used the D-jet cam. The D-jet cam was used on 412 1.8L with L-jet as well. Its very sketechy about when they became bus specific....but the bus got a more advantageous cam.

But either way...all I am saying is that there are MUCH better cams for the bus that will run better and give longer life.

yeah...give the guy the carbs back after he makes it run and you check oil pressure, compression and crank end play...and take $250 off for the carbs. Ray

Thu Jul 24, 2014 4:06 pm

Thanks again Ray, I was confused by the use of l-jet and d-jet to describe the cam I thought it referred to injectors and afc etc of fuel injection.

I'll have to do more reading to understand all that stuff.

It's sitting on a bench so I presume I can only do a leakdown test or half assed compression not cranked by the starter + bell housing or just take a risk.

Can you humour me one more ignorant question and tell me this -- if I buy this engine what other parts should I get to not stress it? Cam + possibly pistons?

Thu Jul 24, 2014 7:56 pm

Well.....these are tough engines if not abused. And if it really was a 914 engine....and the carbs were done well and tuned well....it should have received much less overall abuse kn its life than a bus engine.
If it has all its sheet metal and heat exchangers etc.....from a 914....which would somewhat prove (along with the location of the engine # which is on the case in a totally differnt place than a bus, 411 or 412).....then your first coarse is to check crank end play, pull the valve covers turn it over by hand and check function and movement of all valves.....and if the guy will let you.....pull each set of rockers.....about 15 minutes per side and lay a straight edge across the valve tips. Thats about all the condition testing you can do without pulling the heads of and looking.
Without being able to test run it.....its really not worth $1000. Unless you can show compression and oil pressure......its possibly just a core engine. There is absolutely nothing special about a 1.8L 914 engine. The sheet metal and heat exchangers may be worth $150-200 if they are complete and in good shape, but with the engine only being say....a good core if nothing is obviously bent or broken (which does not mean that it is not worn out with collapsed pistons, flat cam, dead lifters, leaky valves and worn out bearings).....then as an unproven core its worth about $300. Add that $300 to the 200 for sheet metal and heat exchangers.....and the whole pile is worth about $500. If you wont keep the carbs and you have no way to test them (and depending on what they are and if they are complete with linkage and manifolds)......add a max of $100-150.
$650 max.

But to answer your question.....if it is all in good shape on the bottom end ......you strip it down totally, check and clean or replace oil pump, measure piston skirts and bores. If they are original....and no rust or scoring ....they are probably Kolbenschmidt in Mahle cylinders.

I would have a basic regrind of the valves done if there are no spring, keeper or retainer issues and there is enough valve margin, check the main bearings and if they are clean and still anywhere in tolerance...reuse them.
Buy a set of double thrust cam bearings from Jake Raby.....and get a new webcam with matching lifters.
If there is nothing immediate to replace you can have a good running clean engine for about $300 tops with a gasket set. Ray

Thu Aug 14, 2014 8:39 am

one more revival / hijack:

I nabbed that 914 engine but now I have it back and I note the EFI systems are different -- not a big deal because they snipped the main part of the harness going to the ECU so i'd have to use mine, which I note has a 7 pin rather than 6 pin connection .. . but reusing my AFM that is fine. (right? ... )

If I managed to figure out the hoses and hook up my harness & ecu ( form a 1.8 411) to this l-jet 1.8 914 should everything be theoretically OK?

Because of the amount of work that may be needed to complete the unfamiliar set of hoses etc I'm tempted to just steal the parts from this especially the heads with more even valves than mine but it would be good to know it is a possibility to run this one with my harness.. thanks again.

edit: re-reading this thread I see that maybe the heads might be different on the 914 than my 411/412? both are 1.8...

Here's the engine:

https://www.dropbox.com/s/by4l30hbb15gtdf/2014-08-14%2011.46.08%20HDR.jpg

here's where they snipped the harness *##$#$ with different style AFM connector than mine

https://www.dropbox.com/s/3o23pvmrsj8o6ki/2014-08-14%2011.46.34.jpg[/url]