big-valve head

[nize]

some highlights;
-bigger valves!
-bigger ports (more flow)
-thinner valve stems (less obstruction)
-superalloy valves (stronger)
-titanium retainers (lighter, stronger)
-round coil springs (won't bind like the stock flat coil inner springs)
-taller springs for more valve travel (can open valves further if desired)
-stronger springs
-everything is off-the-shelf components for easy replacement/repair if necessary
-works with the stock cam, or can use bigger cams since valves now have more travel room
-all intake and exhaust ports polished
-maintains the stock factory ceramic ports

the valves are top quality manley valves;
http://www.manleyperformance.com/

more info on superalloys (better than titanium);
http://en.wikipedia.org/wiki/Superalloy

from the local 951 race cars past experience with similar sized valves, just the head swap alone should add an additional 40 to 60 hp at the wheels, at lower boost levels.

stock valve vs. new valve;

[PAUERMAN]

That's sweet Peter. When are you going to have this head installed?

[nize]

installing it tomorrow.

too many forums, not enough time...

[PAUERMAN]

I see Bob's block in the background - is he going to using the newer MID sleeves in his new block?

Speaking of new goodies... I finished up my new Vi-Pec V44 harness. It came out really nice and I'm hoping to get it installed by next week.

[nize]

bob's re-using his original MID sleeves, everyone is in agreement they don't really need to be changed. he got piston squirters installed this time around though, check the other thread;
http://forums.pelicanparts.com/showthread.php?t=482146

note those photos are of two different blocks, both which had squirters installed. one is using the new darton MID and one is bob's original darton MID.

new harness looks good! when can we test?

[carlege]

curious? do you re ceramic coat the interior of the head? or just leave it bare does it matter?

[nize]

as already mentioned, the factory ceramic exhaust ports have been left intact.

they do make a big difference in promoting quick turbo spool so it was critical that the donor head have perfect ceramics without cracks.

[kdjones2000]

Peter, if the valve stems diameter is reduced, how can you not change the ceramic guides? Unless only the intakes have the smaller stem I guess.... (Looking at the pictures again, I guess you are talking about the smaller taper between the valve head and the stem reducing the obstruction - correct?).

Great work on this. How much flow would this solution be capable of, compared to a 16V head?

[nize]

Originally Posted by kdjones2000

Peter, if the valve stems diameter is reduced, how can you not change the ceramic guides? Unless only the intakes have the smaller stem I guess....

Great work on this. How much flow would this solution be capable of, compared to a 16V head?

hahah that is a very good question and i was wondering when someone would ask. the valve guides were very carefully replaced with new ones. lots of TLC went into this design and we're not aware of anyone who has been able to do it this way before.



the really big bonus of this method is that you can use off-the-shelf parts so you avoid the high costs of por$che-$pecific components, just like with the darton sleeves and JE pistons.

edit: to be clear, the entire valve stem diameter is smaller, not just the tapered area.

[PAUERMAN]

Originally Posted by kdjones2000

Peter, if the valve stems diameter is reduced, how can you not change the ceramic guides? Unless only the intakes have the smaller stem I guess.... (Looking at the pictures again, I guess you are talking about the smaller taper between the valve head and the stem reducing the obstruction - correct?).

Great work on this. How much flow would this solution be capable of, compared to a 16V head?

The valve guide boss in the head remains the same - the only difference is that the guide uses a smaller ID for the smaller diameter stem.

[nynor]

where does one get this head, or have one's head modified?

[nize]

currently it's for seattle area locals only. there are plans to make it available worldwide. stay tuned.

[nize]

in the meanwhile, if anyone wants to ship me their head, i can get it modified and ship it back. send me a PM if interested.

note that this will only work if the factory ceramic ports are not damaged in any way.

[nize]

here are some comparison photos between the new and old head;





and a size comparison photo with a penny;

[carlege]

Originally Posted by nize

in the meanwhile, if anyone wants to ship me their head, i can get it modified and ship it back. send me a PM if interested.

note that this will only work if the factory ceramic ports are not damaged in any way.

You might want to include the price for the machine work and valves etc.. So people can get an idea of what it cost.

[nize]

$2500 all-inclusive.

keep in mind lindsey charges over $3500 for similar work without the new technology valves, spring design, and materials.

[carlege]

Very reasonable nize but i imagine this would be best suited for higly modified cars, Such as yours?

[PAUERMAN]

You get it running today?

I'm going to be sending Dave a couple of heads so that I can have a few on my shelf.

[nize]

i got it running saturday just after midnight.

i still can't stop grinning every time i think about it.

[nize]

Originally Posted by carlege

Very reasonable nize but i imagine this would be best suited for higly modified cars, Such as yours?

this will work for any 951, even completely stock ones.

you will gain an additional 40whp to 60whp right off the bat, without any other mods and at lower boost levels.

i'd recommend you should have some way to adjust the tune on the car first, though, because you will need more fuel at higher rpm's due to the additional amount of air flow.