I'm considering building a big cc engine to use in my circuit race bug for the open events. But what combo? 82 or 84 stroke.

I do have a ally bubble case, so the case is not an issue. Do you need to machine the camshaft for a 84 stroke with chev big ends?

Yes, I believe you will need to clear the camshaft for an 84 stroke. Chev journals and the right conrods will reduce the amount required, but you will probably still find it will hit.

No you do not have to clear the cam shaft, since i have a bubble top with what you are wanting to do.
i have 94 x 84 with chev journals.
no issues here

No probs depending on the cam, Engle will possibly need clearancing depending on rods, but it's not a big deal, Scat and many others have thier cams preclearanced. My last big build was 88 x 94 and although some clearancing necessary it's not that difficult. Even a bubble top case needs checking.

The setup that I'm looking at is either:

1.
Ally high roof case
82mm CB super race cromoly crank
H-beam rods VW journal
Engle fk89 cam
Wiseco slipper 94mm pistons / mahle barrels
CB Wedge Port Cylinder Heads - 44x37.5mm
Big beef intakes with 48mm ida carbs

2.
Ally high roof case
84mm CB super race cromoly crank
H-beam rods chevy journal
Engle fk89 cam
Wiseco slipper 94mm pistons / mahle barrels
CB Wedge Port Cylinder Heads - 44x37.5mm
Big beef intakes with 48mm ida carbs

The engine will operate between 5000 - 7000rpm with my current gear ratios on the track. The ratios are:
1 2.06
2 1.611
3 1.318
4 1.12
FD 3.875
225/50/15"

We only do 8 lap sprint races, so no enduro stuff.

here is a teaser for you http://www.youtube.com/watch?v=HzD9Rfl-LwQ&feature=channel&list=UL 

that is a lot of rubber,do you need such a wide tyre?

your combo sounds like it'd be ripper...

with your current setup what are doing for cooling "whoops off topic" and how hot is your oil getting doing 8 laps.

That bug sounds pretty cool. There's a lot of torque

In my class I run with cars that's got more hp than me, so the only way to beat them is through the corners... thus the wide rubber.
http://www.youtube.com/watch?v=ekHM0InIm8o 

I'm using a doghouse cooler with one oil cooler underneith the rear window and one cooler in the front. The cooler in the front was made from a intercooler core and is on the dry sump return line. The whole system takes about 15lt of oil. Oil temp goes up to about 105'c on the 30'c outside temp days.

Here's some pics of the oil coolers

Just fit a turbo to what you have Then u will have some usable power FK 89 mainly suited to drag application not circuit nobottom till 5000 then comes on like sledge hammer.2275 vw journals make sure u prep the hi top case and use the grooved metal backed centre maincheers Rudi

None of the competitive race classes allow for turbo charging. Otherwise that would've been an option. I think the first option might be to get a little extra power from my current setup, right now the fk89 is not working like it should... I think the cylinder heads are a problem. It makes max power at 6300rpm and then dropps dead.

Has anyone here used the CB ultra wedge port heads before? Are they bolt on / go or do you still need to grind on the ports before use?

..what about the superpro's with more port volocity for your small engine.

what heads are you using now ?

CB 044 super mag with 42 / 37 valves, 1.25:1 rockers, 48ida on big beef manifolds and 1 7/8" header
I think there's either a problem with the porting or valve springs right now...

Here's a pic of the combustion chamber, I'll try and find some pics of the intake ports

CB springs don't last long IMO

I use cb650 springs and rev mine to 8000 and never have had a valve float.

Your exhaust is big.maybe try a 1 5/8". Anyway your engine sounds great and goes hard on all the videos I have seen

Nice info shared guys

Happy to share

Thank you for the info, normally it's just trial and error as no one in the beetle community like to share info.

I have tried a 1 5/8" header as well, the 1 7/8" made the same power. I have also tried 38mm choke tubes, no big difference there either.

The midrange power is pretty good right now, but only up to 6300... at 6300rpm it makes around 95kw on the wheels on a dastek chassis dyno. (1600m above sea level, no correction). At 6500rpm it's already down to 85kw which is crap.

The cam has been dialed in to the cam card. I have not really tried moving the cam around too much though.

The ignition timing has been power tuned and ended off at 29' advance from 3500rpm. More timing = less power, less timing = less power. The AFR ratios are at 12,8:1 wot which is perfect.

Compression ratio is around 12:1. I can go higher if needed, there's no det.

What size is your current engine??


Also how well does the intercooler.... err I mean oil cooler work??

Currently it's 2165cc

Previously i used two big setrab oil coolers plumbed up in serie, then changed to the home made intercooler setup. The oil temp went down by about 10'c and the dry sump return line pressure went down as well due to less restricion from the big intercooler setup. It was well worth the effort and cheaper than a big setrab oil cooler.

Current setup is:
Cb 78mm super race crank
Cb h beam rods
Wiseco 94's in mahle barrels
Fk89 cam with cb big foot lifters
Cb 044 super mag 42, 37 valves. 1,25 rockers
Big als 1 7/8" header with 2,5" silencer
Cb big beef intakes with 48ida, 42 chokes

And how was the porting in the pics finished? Certainly far from finished in the pics.

Yeah id like to see it with smaller vents and headers with those valves and ports

I'll try to fin some pics of the heads finished, those pictures were while in process but shows the port shape and size.

I've tried it before with 38 chokes and the smaller exhaust. No power increase.

Are the wedge ports the right choise? Or should i look at another brand?