compression question

[ZieglerSpeed]

can anyone tell me how 86-89 318 2 BBL's compression was raised. Different pistons or the swirl port polish heads I'm guessin

 

[ZieglerSpeed]

Ok, I see the 86-89 318 piston has a unique part number

 

[Aspen500]

SOMEONE PLEASE CORRECT ME IF I'M WRONG but, I seem to remember the swirl chamber heads had a smaller chamber cc (by about 10cc????) than the earlier 318LA heads and also require a different piston profile. It's been a while though.

 

[Mikes5thAve]

The change was mainly heads. I don't know what changed piston wise but you can put those 302 heads on older 318s without changing pistons. For a while it was a common swap for people to put them on 360 too.

 

[ZieglerSpeed]

I have a 89 318 I'm going .040. Factory cast are adequate but I have a few choices. 67-72 floaters and bush the rods or the 86-89 style I guess

 

[ZieglerSpeed]

I just bought a new set of the 86-89 .040 cast pistons on ebay for 100 bucks and that includes shipping. The gas door says ''PREMIUM RECOMMENDED'' is good enough for me

 

[Bill Park]

My 88 w150 had closed chamber heads. Lots of torque

 

[XfbodyX]

Ive a set of KB399 .040 to move on to someone other then me.

 

[Bill Park]

I sold that truck a couple of years ago it was tired almost 500000km of trailer towing. My Roadrunner has a 440 so sorry not much good to me