2.3 Compression/Cam

[rwrose]

According to the shop manual the 87 NA 2.3 has a combustion chamber volume from 59.8cc to 62.8cc. According to the shop manual and AllData the Bore is 3.780/3.781, Stroke is 3.126 and Compression Ratio is 9.5:1. The post that I have seen here tends to suggest that 9.5 is incorrect.

My plan is to mill the head to reach around 10.5:1, however, I want to maintain the proper valve clearance without modifying the piston. I am also planning on changing the cam to one with a little higher lift. One post stated that for every .07 milled it would reduce the volume by 1cc. According to my figures I would need to mill about 0.49 from head. I’m pretty sure that I could take 0.60 and not have any problem with any cam, however, I don’t want to find out the hard way.

I have not CC’d my head (don’t have the tool) but would like to get a rough idea on how much to remove. I believe the volume on mine is around the 59.8cc range and doing the math would confirm this. (numbers.txt, chamber.jpg)

I have seen posted that the roller cam from the Ranger was the same lift/duration as the hydraulic cam. Does that also apply to the ones found in the turbo 2.3’s? I want to put a roller in for friction reduction and want to get a little more power and still meet emissions. I have seen a few on e-bay but I’m not sure if one out of turbo motor will work in a NA or will help or hurt. I’m not planning on spending two or three hundred bucks on a cam for a street driver.

Any help or suggestions?

Randy

 

[Touring23]

The calculations look correct to me.
I think you mean to mill 0.049", not 0.49"...!
1 Teaspoon=5cc, Linky. Now you can cc your head.
I would not mill the head .050" if it were mine. An 87 speed density computer won't tolerate much cam; the loss of vacuum at idle causes the idle to hunt/surge/die. Worse, a "small" cam will close the intake valve early and capture more volume, therefore you can't get too crazy milling the head. It's called Dynamic Compression.
*edit*
You didn't say where you're headed with this project, so I'm supposing the goal is simply "more". If that's the case, I would suggest an adjustable cam gear instead of milling and cam. Retard the cam to move the powerband up.
I reckon if you mill the head .050" with a factory cam it's going to go blammo.
Hope this helps. Sorry to be the bearer of bad news.

 

[rwrose]

Your right

Thanks, and you are correct, I left out the zero.

 

[140CILX-Coupe]

by accident or other?

 

[VisChaos]

What is the benefit to the Ranger cam?
With my n/a can I just yank my cam and slide a ranger cam in?

 

[Turbo_Raccoon]

the ranger if you use the rollers you will have less friction so less cam wear and somewhat cooler oil temps. and yes it will just slide in there.