d15b2, d16a6, cam and head decision w/ boost and now w/melted piston pics
 

I'm putting another engine in my car. I fried the pistons on my last built a6. I just picked up another d16a6 and a d15b2. I'm gonna drop in the b2 for now. I will only have this motor in the car for a couple months till I get the a6 built. I'm gonna boost whatever combo I put in at the moment with a evo III big 16g at 8 psi. Just curious of the cam difference between the si and dx. I will just use dx head with an mpfi intake mani and distributor if there isn't gonna be a noticable difference with the si cam. Or should I just drop on the si head? I'm guessing there isn't a compression ratio difference between heads.

Re:d15b2, d16a6, cam and head decision w/ boost
 

the dx and si head are of the same pm3/pm7 head castings the dx cam has much smaller spec'd lobes than the Si imparticularly the intake lob, i would either swap heads or either just swap in the Si cam as they are interchangeable, be careful with the rocker assembly if you swap cams, make sure to LEAVE THE BOLTS IN or youll have 50pieces and spend 30mins putting it all back together this includes with a friends help since its all spring loaded, trust me i know, learned the hard way long ago

Re:d15b2, d16a6, cam and head decision w/ boost
 

eh... What are you going to gain with the A6 head, like 5 hp? I have an A6 head on my DX. Never boosted with the DX head but I don't think the A6 head made much difference. Umm, sure why not toss it on, can't hurt you know.

Re:d15b2, d16a6, cam and head decision w/ boost
 

yea at the most i would say 5hp, but overral its overlap and ability to let the motor breathe should help a boosted motor thats all i was trying to say

Re:d15b2, d16a6, cam and head decision w/ boost
 

If both motors are all together I would just leave it for now. No sense in buying a new head gasket and doing all the work if you're only going to be running it for a couple months. You probably won't notice a gain anyways. :-\
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Re:d15b2, d16a6, cam and head decision w/ boost
 

i vote just swap the cam, it wont cost you ---- to do it except maybe a 10buck valve cover gasket

i did the a6 cam swap into my 95 dx, mid-top end improve quite a bit over stock, only wish i had a higher revlimiter, it breathes all the way to 6800 probably past, on the dyno my hp and tq peaked at revlimiter with this cam

Re:d15b2, d16a6, cam and head decision w/ boost
 

Thanks for the replies guys. And Dr. Boost, I'm ------ paranoid and I had to at least rip something apart and look at it. I had to pull the pan anyway to swap on the oil pan from my other a6 with the oil return pipe. And of course I had to pull the head to check things out as well. The piece of ---- d15 head gasket is junk. Half of it is stuck on the block and half on the head. I doubt that would have lasted long with boost. I've got all these parts with 5000 mi. on them just sitting here from my built a6 (hg,arp head studs, water pump, oil pump, timing belt). So I'm gonna clean the surfaces and put on my arp headstuds and d16z6 hg with some copper spray. I've also decided to replace the water pump, oil pump, and timing belt (all from my other motor) and swap in an si cam that I have sitting here (original cam from my built a6, now have a crane turbo joint). Well at least I won't have to rip anything off of the other a6 at this point. I'm just thinking now that I'm doing too much work for nothing. Well, who knows? The b2 could have 180,000 mi. for I know and the water pump could take a ---- in a couple weeks. I guess better safe than sorry. :-\

And for everyones enjoyment here is 2 pics of my fried pistons.
http://usera.imagecave.com/ahsnowbd/...02779-copy.jpg
http://usera.imagecave.com/ahsnowbd/...02780-copy.jpg

Re:d15b2, d16a6, cam and head decision w/ boost
 

damn someone was knockin like nobodys buisness, do i see some meltage? possible NAWWSSS?

Re:d15b2, d16a6, cam and head decision w/ boost
 

Motor sounded fine. Also ran good. Good compression as well. No NAWWSSS, but some boost. My car kept overheating and I pulled the head to check/replace hg and this is what I found. I had my timing set wrong. Good way to waste a couple hundred bucks. :(

Re:d15b2, d16a6, cam and head decision w/ boost and now w/melted piston pics
 

for having timing off a little thats alot of damnage, was your ---- just so damn load you couldnt hear it pingin like hell?