225 Refresh Questions

As part of my current 71 CJ-6 build I am going to go through the engine and give it some love. It supposedly had a rebuild only a few thousand miles ago by the previous owner and it makes good compression. That being said that was over 12 years ago. I have gone through the 225 blueprint thread multiple times and I am going to try to duplicate the oil pan mods as well as do the high volume pump. Additionally, I will upgrade the water pump. Other items that will be added are Novak headers, HEI, and fuel injection by Summit or FItech.
I also have an Offy 360 single plane intake that I can use. My question is does anyone have any experience with the single-plane intake? is there any advantage to porting and polishing the heads or intake to get low to mid-range torque? and what grind do I want on the cam with this intake or is it just the completely wrong fit for my goal of low to mid-range power and torque? I know this may not be optimal but I am trying to net gains based on stock performance. Any other mods or upgrades I should look at?

 

Is the Offy 360 actually a single plane manifold? The only one I'm familiar with is the dual port version which does work well for low end torque. My CJ 5 has a Comp Cams 252H cam, the Offy 360 manifold, Holly 450 cfm 4150 carb, and Headman headers. The only head work was the addition of hardened exhaust valve seats. It has 4.88 gears and an OD and will go as fast as any sane person would want to go with the rest of it bone stock. That cam works very well both on and off road.

 

IMHO Port, polish, and even blueprinting is overkill unless your setup for racing. Balancing is good. I like TA Performance timing case upgrade along with their high pressure oil pump kit. high flow water pump and thermostat is helpful in cooling and preventing air pockets. Offy dual port intake is very good along with either a holley 390 CFM or a AFB 400 CFM. TBI is also good. HEI helps but you need to make sure to run a 12/10 gauge wire circuit to it. Also increase plug gap. Once all done, have the Jeep dyno'd to dial everything in.
AGAIN, this is jut my thoughts and experiences working on V-6's and with customers and friends.

If ya have one laying around, how bout a Buick 252 turbo V-6----fun motor! bolts in place of a 225.

 

Yes, it is a true single plane. I thought they only made the 6035DP as well. There is lots of info on that one but very little on this single port.

 

If you have good oil pressure with the regular oil pump, I would recommend leaving the high volume one off the table until needed to save wear on the cam gear and distributor gear. If you have good tolerances, you should be ok on oil pressure.

 

Reason for mentioning a high pressure oil system is when serious low 600 RPM wheeling, the 225 does not have good oil pressure. We tested this with a mechanical oil gauge, a darn steep hill, granny gear(SM420) low range X-fer, 4:88's, and the oil pressure was 4lbs. The lifters were very unhappy. Installed a H.P oil system and redid the test and had 10lbs of pressure. One can adjust the pressure by milling the oil housing plate, thickness of plate gasket, and increase/decrease the spring tension. I think I/we spent to much time doing "what if" stuff, LOL. Kenne Bell help us out a lot as well.

 

My Number one goal is to keep this engine oiled and cool. The info on oiling upgrades on this group alone has been so valuable. Sounds like that is where should keep my focus. Ive been perusing the TA performance catalog looking at the timing covers and water pumps.