if i put one on my 91 digi what will it do, i dont know much about these engines want to stay with 8 valves but do somthing different you dont see the crossflow motors often just wondered if any one could tell me a bit about em cheers ! joe.
You could run TB's as you'll have alot more space to do so. The head from a 'new' beetle is prob the easiest to find over here. Just out of curiosity why do you want to stay with 8v?
I think crossflow heads have a slightly different face onto the cylinder block of a 1.8. ie the headgasket surface on both is different. The 2 litre block is ok but not 100% on your 1.8 pb block though even if it is a late one. The block needs a bit extra under one of the front oil drains. Being digifant you will need to address how you are going to run it. Management or carbs / itbs.
YEAH, THE OIL DOWN DOWN THE FRONT OF THE HEAD DOESN'T LINE UP PERFECT, BUT YOU CAN FILE IT AWAY SO IT AIDS FLOW OR EVEN TRIM THE GASKET A TAD. IT'S NOT EXACTLY GOING TO CAUSE A BLOCKAGE. i'VE DONE ONE ON A 1H RALLYE BLOCK (BUT TURBOED INSTEAD OF SUPERCHARGED) AND IT WORKED FINE. (FIRST ONE IN THE UK TOO I BELIEVE)
Nothing "at all" wrong with an 8v... The crossflow heads I've seen need a LOT of porting work to.... work, due to their swirl design, cant tell you how bad yet until I get one on the flowbench. Cutting the bowl/throat area back to a similar shape to the old style head produces "fresh air"... i.e, big holes! This can be welded up and then ported in the normal manner. There maybe some versions on the crossflow head that are more like the old style... worth investigating. There looks to be more potential in the port sizing tho due to the distance between the ports and the head bolts holes, so potential for bigger ports to feed bigger valves.
if you can get hold of the ABA engine head (sold in the states only) that'll give you crossflow 8valves, with the bonus of being a straight fit onto an AGG or a 2E 2l bottom end. should fit the PB too, but not 100% on this.
hmmmmmm il look deeper into this ive also just been given some vr injecors a good idea on a pb for the time being or not???? cheer joe.
Yeah I've seen those pics before (I think you posted them Brookster!)... any info on that conversion, looks good for a road car set up, could be the way to go to overcome some of the issues. I been looking at that lately... may also be able to get away with it on my hillclimber in my class.... hmmm. There'll be one going on the flowbench in the new year, see wot we got to work with.
Mr Hillclimber, Have a good look at the way the cylinder head oil drains into the block at the front, I think below no 2 spark plug. It is slightly different than earlier 1.8 engines (DX for instance). The newer 2.0 blocks have an extra bit of casting in that area so it is not an issue with them. If your rules mean you have to use the original engine block it may be an issue. Possibly filling / welding the head a bit could solve any issues. That is what the Ford folk do when building their Zetec / CVH hybrids.
http://cgi.ebay.com/ebaymotors/VW-Golf-Jetta-Passat-rebuilt-cylinder-head-2-0-2-0L-ABA_W0QQcmdZViewItemQQhashZitem19b88979aeQQitemZ110470199726QQptZMotorsQ5fCarQ5fTruckQ5fPartsQ5fAccessories
There are plenty crossflow heads in the uk now as the mk4 golfs become "not economically viable to repair" I like modern plastic cars as they make excellent donors for old cars!
Thanks for that... I've not look that close at them yet, but thanks for the heads up. I do have to run the original type block, DX or EV, as long as it's not a 16v block with the big breather hole in the front I'm ok. The rules just state number of valves have to be the same, valve opperation has to be the same, as does manufacturer and material, induction is free, does'nt say it has to be in the same place!... though I'm sure it'll upset the applecart if I turn up with one. I understand the heads line up on on the 2ltr tall block ok, welding would be easy enough, I have a man who can!
What no-one's mentioned yet, as far as I've seen, is that there's no major benefit to this unless you're building a highly modified engine. Chucking a standard X-flow head on a PB block won't do much. If you're talking ported heads, lumpy cams, high compression, and ITBs or big carbs, that's different.
Mr hillclimber, If you have to use an 8v block try and get a look at the last of the 1.8 digifant blocks as i have seen one out of a J reg car that had the later oil filter housing bolt pattern like the newer 2.0 blocks. I wonder if it maybe has the extra metal around the oil drain from the head area. I do not have that block anymore to look at to confirm though. As the crossflow head is a hydraulic tappet with 5 cam bearing caps it is possible to fit mechanical tappet cam (bigger base circle) if the follower bores are relieved slightly for the lobes to pass without hitting. I had to reduce the diameter of the end of the cam that controls end float though as it was slightly to big and would not allow the cam to sit properly on the bearing surfaces. Took a while to spot this as it was only hitting by a tiny amount. Could have snapped a cam if i just tightened down the bearing caps. I am in the process of sorting followers that will allow under tappet shims to make up the difference between the hydro and mech tappets. Danny
