Wibble\'s hybrid engine

Well i've started to get a little more serious with Wibble's wrx headded vw hybrid engine.

After a lot of measuring, a bit of design with autocad and some cardboard templates i've finally got a head-stud conversion system that will work.

The aluminium head plates that block off the water cooling galeries and oil feed to the head were CNC machined at my work. The 12mm steel stud adapters I had water jet cut.

The plan is to use 8 x 10mm high tensile bolts to torque the stud plates down to 25ft-lb. Then 6 12mm high tensile bolts come through the head plates from the bottom of the plate to bolt on the wrx heads to 30ft-lb.

The cam drive system will involve machining up some new hubs that are longer to account for the extended offset needed to get the timing belt to drive off a pully in front of the standard power pully. It will actually work out pretty well as the intake and exhaust cam timing will be fully adjustable. Save to say i've learnt a lot in the past few weeks about how cam timing works in a 4 stroke engine. Its been like craming for an exam.

Lubrication for the OHC heads will come from what is normally the full flow oil return. The oil return from the heads will return to the sump via fittings that will end up screwed into two of the pushrods tube holes. The other two will (each side will be blocked off).

So... Here we see wibble's shiny new empi bubbletop aluminium case. 10mm head studs, 94mm barrels, clearanced and full flowed, some wrx heads courtasy of Reub, and a pair of 94mm barrels



Here is the CNC machined and waterjet cut head and stud plates.



This is the barrels slipped into the case with the head stud and alloy head plate slipped on.



This is a pic of one head sitting on top of the whole lot.



And again from another angle.



As mentioned earlier, the eventual goal of this engine is 12:1 compression, 7300 RPM, and 200+ naturally aspirated HP. 2180cc (78.4x94).

The prototype is using turbo heads so the compression will be closer to 9:1, but that will do for a prototype. The wrx heads are definatly a lot more suited to a forced induction application. The potential for the prototype would be amazing with a pair of GTR R33 turbos's on it. I'd figure 400-450 HP would be an achievable figure if we got the flywheel wedgemated.

As for whats next, i've got to trial fit the other side of the engine and then buy some high tensile bolts to trial bolt it all together, which is a project for next weekend.

As for my car, its stripped again and is having the flaws and a few scratches fixed. Should be at show quality in 3 weeks, just in time for a car show on the 29th of October.

I'll keep you all posted as to the progress of both projects.

Cheers,

Will be wild DUDE.....you guys are nuts!

Keep it up, will be interesting to see running.

Choice ! nice stuff, this is one thread I will be watching with great interest.....

Interesting project Ian! Just a question,have these heads had any porting or new Timing sticks inserted?...JVLRacing

Man , thats the go !

The heads are stock for the moment which will do for a prototype. Later when the heads are changed to naturally aspirated EJ20 heads, they'll be ported to the limit.

Cams are stock too for the moment. The timing will be adjustable with the new cam pully's. The turbo cams don't have a lot of lift at all. I'd imagine the naturally aspirated ones will be a little different.nn[ Edited on 25-9-2005 by iswinkels ]

Okay:thumb...If you go back to a Turbo set up you will need to flow does heads and bigger timing sticks accept 300+400hps...especially with big turbo set ups.JVLRacing

This is a 100% naturally aspirated design. IMO a turbo vw engine would be fine running on a VW configuration cylinder head. The reason for the development of a 4 valve OHC configuration engine is to allow more more revs and airflow.

Turbo engines don't need to rev to make good torque and hp, and all a very good and strong turbo engine needs is lightly ported and tidied up intakes and opened up exhausts to get that hot gas out faster.

Today I sorted out the other side of the engine. I'll be picking up head studs this week so I can bolt it all together, and start working on the timing belt drive and tension system.

I still need to source a crankshaft timing pully and a spring style timingbelt tensioner...

Here's another pic..

mmmmHave fun:thumbJVLRacing

You should use suby cylinders too, then you don't have the distortion / cooling / blow-by issues of the VW cylinders.

I guess you have to draw the line somewhere though, otherwise you'd just end up with a suby engine...

Baja Wes wrote:You should use suby cylinders too, then you don't have the distortion / cooling / blow-by issues of the VW cylinders.

But they don't have fins so it couldn't be air cooled? or could it?

You'd have to completely re-engineer the block to allow the cylinders to line up, fit square and allow water to go thru it, or as wes might say next.... use a suby block too 😀

The suby cylinders are only 92mm too, so we'd loose 100cc in displacement.

The heads are remaining water cooled, and the cylinders will be air cooled like that engine from the uk. I don't want to go re-inventing too many wheels...

nn[ Edited on 26-9-2005 by iswinkels ]

Maybe you could just put a porsche fan shroud and set of 48IDA's on a suby motor, and then tell people it's air cooled...

I think he just wants have a foot in both camps. :P

Yes it will be air cooled using a porsche style setup, but fabricated from aluminium sheet.

The first time it will be started it will be using a vertex magneto ignition and will be being fed with a pair of 44 idf's, which are way to small for the engine to breath, but will be enough to allow us to prove the cam drive system. depending on how well it works out, the version with naturally aspirated heads will run wolf efi with quad 50mm throttle bodies.

But i've got to walk before I can run. I need to track down a crankshaft timing bely pulley before I can go any further with the development.

Are you thinking of selling it as a kit in the long run?

I can't think that far ahead! Its possible, but making the custom crank pully will be time consuming. I've come up with a design to machine it out of billet aluminium and its not going to be realy cheap at all. To make it a viable kit i'd have to get everything made in china. I need to get one working prototype first. I might just make the plans available freely if it all works and isn't cost effective to produce as a kit.

I want it! oh hang on..........

Man I'm sooo pumped to see how this works out. Giddyup Aussie know-how!


Keep up the good work mate.

Wibble, thats just nasty...... 🙂

This is going to be one truly evil manx buggy once you boys are done with it.......

Keep up the good work !

You could probably write my engine building knowhow on the back of a postage stamp with a texta, but im impressed with the concept of this donk and the obvious knowhow behind its development! good to see 👍

Well today the machine shop guys at work made me a timing belt drive pully, so i've been able to start nutting out how to drive the cams, change the pully offsets and drive the fan/alternator. Dam its good to work for an engineering company sometimes!

The system will use two idlers and one tensioner. The idler on the right will drive a v belt pully which inturn drives the alternator.

It looks a little abstract at the moment, but it should work.

The next step is making the cam gears. And here's some pictures!







[ Edited on 29-9-2005 by iswinkels ]

Hi Ian

I had the same idea some time ago. I wanted to fit it to a Type 4, but could not find heads for the measurements.

Can you tell me how far the bore centers are from each other.

I planned to bolt the stud plate against the block, and have them machined so that the cylinders would locate and seal against it (that would make the block very strong). I would have shortened the cylinders by the same amount as the thickness of the studplate, or until my deck height is right. I would then have fastened the heads with (6) 12mm bolts (per side).

I think your setup looks great, and with a bit of work, would also work great.

Good luck with your project.

Hermann

Wow that looks complex. Will the pulleys easily handle the extra load? (sorry if this is a dumb question)

Adolph wrote:Hi Ian

I had the same idea some time ago. I wanted to fit it to a Type 4, but could not find heads for the measurements.

Can you tell me how far the bore centers are from each other.

I planned to bolt the stud plate against the block, and have them machined so that the cylinders would locate and seal against it (that would make the block very strong). I would have shortened the cylinders by the same amount as the thickness of the studplate, or until my deck height is right. I would then have fastened the heads with (6) 12mm bolts (per side).

I think your setup looks great, and with a bit of work, would also work great.

Good luck with your project.

Hermann

The EJ20 heads are the same as a type 1 head. I think that UK engine is a type 4, and I think its using EJ22 heads.

I was originally going to plate each side of the block too, and then use longer rods to increase the rod ratio and restore the deck height. But there was a problem with this. The number 3 cylinder is very close to the rear of the engine, and there is no room for the plate to support the rear two subie head studs.

The new pullys i'm making will be able to support the load just fine. The belt tensioner will maintain the belt tension to subaru specs.

"The number 3 cylinder is very close to the rear of the engine, and there is no room for the plate to support the rear two subie head studs."

I think that is something you would only find out when you have the heads in hand.

Good luck
Hermann

Very nice! Its great to see people thinking outside the norm.
Could you run the alternator from the timing belt (changing the alternator pully) it would be like a mini glimer type setup.
How heay are the subi heads compared to vw?
Any more pics?

bluebaja wrote:Very nice! Its great to see people thinking outside the norm.
Could you run the alternator from the timing belt (changing the alternator pully) it would be like a mini glimer type setup.
How heay are the subi heads compared to vw?
Any more pics?

Thats not very practical if the alternator needs to come off for any reason, having to reset the timing belt

A few days ago I scored a set of 4 timing belt pully's and a set of tensioners and idle pullys so this has allowed me to work out exactly how the timing belt system needs to go together.

For the moment the dual pulleys on each cam are bolted on, but they will be welded together and then machined back to where they need to be to allow the belt to run squarely on the pulleys. I also got a 4.5" power steering v-belty pully to drive the alternator from the wrecker.

I've made up a template for the alloy backing plate that holds the tensioners etc, and should have it bolted to the block by the end of the week if I have time to finish it.

Yes the idler pully that drives the alternator would have to be removed to replace the alternator v belt. I don't see this as a big issue though as once its setup its just a case of painting marks on the pullys and belt as locators. Any which way that would happen less frequently than valve clearances have to be checked.

Here's a pic of the revised timing belt drive system but still with a 5" pully.



Cheers,

Holey crap batman! so how's a simple person like myself gonna maintain this thing, dude you are never moving out!!!

So here's the latest update. The timing belt system is mostly sorted out.



The latest engineering challange is that i've outsmarted myself by going to an engine case that uses 10mm head studs. This means the grade 12 high tensile head stud bolts I was going to use have heads that are too big, and they don't allow the barrels to slide on through the stud adapter plates due to bolt head interference. The barrels will fit if I am able to machine 1mm off the outside of the bolts, but how do you machine grade 12 steel?

I've got an indermediate solution though that will allow me to get the heads bolted on and start messing with cam timing, and piston to valve clearance checks. With any luck by the end of this weekend there will be a crank with rods and pistons in the engine, and the heads bolted on.

This is impressive stuff, I am very interested to see how this motor runs.

If you cannot machine the bolts, have you thought about getting them ground. Grinding can take material off any thing though it is usally a bit pricy... Just an idea that may help you out


:thumb:thumb

Another update. I've finally got one of the two heads bolted on. This is the easy side done. The head studs on the left side of the engine are more complicated due to the cylinder offset. With any luck i'll get that side done tomorrow.

Ran out of time today on account for going to the local 1/8 mile drags.

Anyway, here's some pics. I'm only using 4 head studs for the mock up, but the final will use 6 like a normal subaru. They are 12mm HT and will end up being torqued to abotu 35ft-lb.

The two center and two front main bolts will be removed and longer studs fitted that will further strengthen the stud adapter plates. I'm toying with the idea of running thru studs on the center mains after i have the engine running once.



Check the size of the intake ports on the heads. They are about the same size as the intakes on competition eliminator heads and have room for porting too. The exhausts are 1.75" in diameter.



Cheers,


[ Edited on 22-10-2005 by iswinkels ]

Well both cylinder heads are on now and its looking pretty good. The stud adapter plates came out quite well but I need to adjust part of the design so they clear certain sections of the case more easily.

I'll be geting one more set of plates machined before the engine goes together in its final form so it can be started. As it is at the moment it will allow me to install rods, pistons etc, and check the piston to valve clearances.




Here's a pic of the exhaust ports, close on 2" output size, so easily good for 8000 RPM.



One last pic.



Next on the list is to order a set of scat 5.7" rods with 3/8th rod bolts. I can then machine the barrels to restore the deck height to about 0.040".

The project is going to be on hold for a few weeks now because i'll be re-assembling my car after picking it up from the spray painters this wednesday with any luck. Be prepared for some tastey updates being posted for that too.

Cheers,

WOW!! The things that some people do in their spare time.

I have no doubt that Drs.Porsche, Fuhrmann and Pieche would be suitable impressed, although they may miss the point.

motor p0rn !!!!!

nice stuff Mr Swinkles, good to see progress being made and thanks very much for the close up photos - illustrates the system very well.

With any luck the 5.7" h beam conrods arrive this week, so next sunday it will start getting really serious. The complete bottom end build up, and then the fun part of working out the camshaft timing and piston valve pocket notching.

Excellent!!!!

Will it be injected or carbies..If you ran a high rise wrx manifold and stepped it back a touch it would probably fit over the back of the Porchse fan shroud. Although I am sure you have pondered this as well whilst trying to get to sleep. Really nice work!


Matt

Induction is the least of my concerns for the moment, but long term I'd like to see a set quad 50mm throttle setup with direct port injection. Wibble's got a bunch of webbers and an old vertex magneto lying around though, so the'll most likely be whats on it when its started the first time.

I was just looking at the timing belt set-up. Do you think you have enough angle of belt wrap on the exhaust cam pulleys? I'd be worried it would jump at high rpm which would be expensive.

you might need some more idlers...

Your absolutely correct. There will be more angle being put into it once the last of the machining is done. The cylinders need to be machined down about 12mm each side to allow them to insert deep into the steel head stud plate. This will give me about 2" more belt to wrap further around pullys.

dare I ask, but what is the odds of you producing a kit? If so, what sort of bucks would it be?

If it works I suppose its possible. All I have now are the autocad plans for the parts I've designed.

As for making the parts again, alas the machining company I am working for has gone broke and sold most of their assets, including the CNC machine. So I can't get prototype parts made for free anymore. Much of it can be waterjet cut though and all shops that can waterjet cut accept autocad drawings.

We'll see how this works out. If it does work, and it proves to be a reliable option to convert to wrx heads, and there is sufficent interest who knows.

As a kit i'd want to get the cam pullies fully CNC machined as single piece components, which will be fairly expensive.

There is quite a lot i've learned already so far though. For example using 92mm bores would be a sweet solution because they could be bored to accept WRX forged ARIES pistons that are already pocketed for the 4 valves. I'm going to have to notch my own valve pockets in the 94's, or order some wiseco's. For the prototype i'll probably notch to 0.140" and then run a decent deck height to keep things safe. So long as it runs there is always room for fine tuning later.

Hey Ian any progress on this?
we are waiting with great anticipation
Mitchell

Mr Swinkles,

In the mad rush of the silly season have you had a chance to work on this work of automotive art ?

in other words....

got an update ?

Cheers,

Doug