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buildabiggerboxer · Post by **buildabiggerboxer** » Sun Jul 12, 2009 11:22 am

had a day in the 'shop today, yes, Sunday, doing all the fiddly stuff i cant do working days, mainly cc' ing various items, interestingly, for me anyway, i did a half dozen wbx head chambers, the d.j chambers come in at 18cc !! i cant see the 15cc that seems to be the norm quoted except on a d.f head, the one with tiny valves, the chamber is visibly smaller than dj/mv... i then cc'd an amc head, 18/19cc... then i did a dj 10.5 piston dish
at 35cc.. so you have the average euro d.j at 9.8 , run it at the mythical 15cc? bit better at 10.3... all these at 1mm deck. it pays to measure twice
after all, im glad i didn't get sloppy..

tencentlife · Post by **tencentlife** » Sun Aug 02, 2009 11:32 am

I keep puzzling about your measurements. because I've cc'd AMC heads and they have measured at spec, 15cc. I can see being off 1cc, but 18 seems way off. MV pistons have come in at 47, as advertised.

We don't see DJ's this side of the pond but I remember reverse engineering the math and I think I came up with about 35cc for them to make 10.2:1. Don't quote me on that, though.

What method are you using to cc? My method would have an error of not more than +/- 1cc on heads (using direct volume), +/- 0.5cc on pistons (using weight, the more accurate among the means I have).

buildabiggerboxer · Post by **buildabiggerboxer** » Sun Aug 02, 2009 4:01 pm

tencent, i use a glass medical burete to cc, plus the usual disc, i mix white spirit with a touch of trans fluid to colour it. the speed shops all sell those dumpy plastic plunger measures, that might be o.k for cooking, not for me tho', so i'm accurate enough. i was mainly surprised at the German o.e heads being 18cc. i'm stuck for pics at this time as my car was raided for the second time and my camera went among other things. seems there are variations out there and id' like to be on top of them. ive a couple of race motors on the go using long rods, i see you've been along that route already so ill post up as i go. I'm slightly worried about the valve pockets getting thin in the ring land area, I'm using web 86c on 1.4s. so about 5.60 lift. maybe ill creep up on the clearances with a stock length rod firstly, with plenty of play doe , they're marle 98s so f/ups are not on, ...

tencentlife · Post by **tencentlife** » Wed Aug 05, 2009 4:00 pm

Well your cc measurement tools are far better than mine, but I got consistently 15cc in new AMC heads and did it several times to be sure. I might be off one cc but never three. I never bothered with measuring OEM heads as I would never be using them anyway; all my builds get new AMC's. Maybe there was some variation in OEM heads for the different builds. Hell, why not? As far as I know AMC only makes one wbx head but it would't be the first time we found out there are different products for different markets.

buildabiggerboxer · Post by **buildabiggerboxer** » Tue Sep 01, 2009 12:40 pm

they hit! did a mock up on the wbx 98s today, using a stock 5.4 rod, plus 100 thou on the adjuster to simulate the 5.5 rod, the good news is that the danger of breaking into the ring land has moved into the green area, the exhaust pocket needs just the dish side edge machining, the inlet, bigger obviously at 44mm is still safely inboard enough for me to shelf the brave pills. next i'll deck the pistons and do a more accurate impression before making up the cutters. the heads i'm using have sunk valve seats, they were turbo heads, so with stock height valves there's not much valve deck to play around with, i dont think a 5.6 rod would work, at least with a big cam and ratios on the mahles. the mahle head gaskets are .052" compressed, .055 new, didnt crush as much as i thought they would .wonder why they did that ?.
looks like i'll have to poke them out the top, progress anyway..and a new camera!

buildabiggerboxer · Post by **buildabiggerboxer** » Thu Sep 03, 2009 2:17 pm

today i got down and dirty with some used amc heads, yes at last, 15cc..
the chamber cuts across sharper than the German 18 cc chamber in the pic. from the plug hole to the inlet valve is 'short cut' instead of the curved chamber shape shown in the German head on the right. i recon the European d.j got 15cc, the mv got the 18cc's. on the left is a turbo head from my okrasa 2500, originally 28cc, now 24cc. the chunky ex valve guides are a must ive found. I'm converting it to atmospheric which is the reason for all the measuring and stretching, the sunk valves are helping the problem of short valve spring deck with big cams and ratios. I'm going with these with a half mill' plus deck to burn more of the void area. doubters say a chamber and a piston dish don't go together, i say lets try it and well see...

51MAN · Post by **51MAN** » Tue Sep 15, 2009 3:50 am

Nice work, where abouts are you in the UK?
Maybe meet up some time?
I have a NOS 98mm Oettinger 2.5 piston and barrel set.. I'd like to build that, but funds are very short now.. need to get a 2.1 put together soon though..

fastback · Post by **fastback** » Tue Sep 15, 2009 6:09 am

Good info here
i have done some mod's to my 96mm WBX Wisecos.
due to limited machine park , yhis is how i did it

ending up with around 1-2mm material at the thinnest part around the 1 ring.
high lift cam and bigger valves + i wanted more "space" sround the valves.
as i see it ,there will not be so much pressure difference betwen the top of the piston and the area around the 1 ring.
they hold up at 23 PSI boost so far.

buildabiggerboxer · Post by **buildabiggerboxer** » Tue Sep 15, 2009 12:38 pm

thanks guys, ive seen quality from you's also! a common cause breeds innovation. my motors have been unused since the 1990 recession, luckily, the okrasa was unrun and never had coolant in it, it was expensive!! but time had taken its toll. i also have a 2.1 that was not so lucky with the corrosion, but both motors are nearing completion, the original equipment bolt set i took out from the okrasa, it came with a race bolt set, has helped save the 2.1. these are race only motors by the way. I'm converting the okrasa to atmo, harder i think to go back than going turbo was!! the info on the ring land thickness helps fasty thanks, , i get them back from machining w/end to do a more accurate top deck and valve deck check. ill be nervous cutting the mahles . some bas flywheel bolts came yesterday, quality , so a bit more done.

buildabiggerboxer · Post by **buildabiggerboxer** » Fri Sep 18, 2009 2:31 pm

the 98's are cut so i can crack on with valve pockets, they will be very close to the ring land fasty, i have long rods, i hope they don't prove to be tooooo long. i also have a 228mm flywheel chopped and balanced surprised myself when i saw the weight,... only 8lbs, so that will do nicely as there is now a good range of centre plates to suit, i have no doubts a stock 228 pressure plate with a sintered disc will hold up to 250 hp in a 750 kg beetle. heres the bas f/w bolts.
http://s254.photobucket.com/albums/hh11 ... DC0010.jpg

fastback · Post by **fastback** » Fri Sep 18, 2009 3:01 pm

depends on your torque numbers though

yeah it should hold up. i had same setup in my turbo WBX oval using the stock plate and a 3 puck sinter.
300-350Nm of torque in that engine

buildabiggerboxer · Post by **buildabiggerboxer** » Sat Sep 19, 2009 11:06 am

3 puck rocks, less inertia cleaner shifting, i wont have turbo torque so yes, should hold it, clearanced the bell/h' today, i look like the tin man! also clocked up the piston heights/ liner heights/ rod heights, all good.
photobucket password rejecting... grrrrr. more picks coming..

51MAN · Post by **51MAN** » Sat Sep 26, 2009 1:59 pm

Nice...

PM'd yer BBB

buildabiggerboxer · Post by **buildabiggerboxer** » Thu Oct 01, 2009 10:42 am

51man, thanks for kind comment, as a one man band, i just don't get the time for pms,! my work load is very high, but i suppose I'm lucky in that i have work for a long time ahead!! and yes i do most , except machining, balancing and seat installing, I'm loath to recommend these days, as standards are definitely falling even with people ive used for years and long established, i get @@@@ up after @@@@ up so I'm moving to new people, and one of these i can recommend for all rod work, balancing, seat installing,offset crank work, in fact all precision work. the company is called GOSNAYS, they are in romford, essex. www.gosnays.co.uk
i see you have a 98 mahle p/l set. i found the piston crowns hugely tilted
on mine,as much as .007 across the worst, all of the remainder were 3 or 4 thou, we had to true them up before decking, final balancing will be fun, as there's not much 'spare' metal on these to remove, so gun drilling the pins may be an option. German precision? fable. taint so.. check every thing, rant over...

51MAN · Post by **51MAN** » Mon Oct 12, 2009 2:37 pm

Cheers
I'll give them a look then...

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98 mahle p/l kits