crazydog wrote
Is there a difinitive point when the oiling mods "need" to be made? RPM, HP..?
When would the decreased oiling cam bearings and push rods "need" to be used?
There are a bunch of different options on the oil pumps. What adds to the functionality, duribility, or performance and what is more visual? Like the nickel plating?
Stock iron heads vs. Edelbrock aluminum heads, what are the recommended maximum compression ratios for each using 90 octane?
Has anyone used Rhoads lifters? I have been looking at the new V-Max ones. In reading how lift and duration are decreased at lower RPM's, would one still run the same cam they were considering with normal lifters and in theory pick up some extra torque down low, or go one step larger on the cam and have more top end when needed?
Also, if you have any extra tips or advice, please feel free to throw some in. Thanks for your time.
1 + 2) OEM AMC engines ran for 100K+ miles from the factory. A good quality rebuild is all you need unless you're running it up to red line (about 5500 RPM) for any extended periods.. The oil restricting cam bearings don't hurt anything, just depends on what you want to spend.
3) An oil pump within factory spec is critical for proper pressure/volume. If your factory cover is within clearance specs, and has no excessive scoring or wear in the walls, you can use it. I'd replace the pump gears as part of the rebuild. The filter adapter should also be replaced for a new style one without the filter bypass. The nickel coating on the Bulltear covers increases the hardness of the walls of the pump housing, making them less vulnerable to scoring than just aluminum. A Bulltear mid plate is cheap insurance, I have one in both my AMX and CJ.
4) For street use, stick with a set of steel heads. A good 3 angle valve job and mild porting, and you'll still have money left over for other mods. Replace the springs and have positive seals added as part of the rebuild. With 90 octane, keep it around 9:1, no more than 9.5:1. With aluminum heads, you need to raise compression about 1 point over steel just to compensate for thermal loss in the cylinder.
5) Rhodes lifters are noisy. I had a set in my CJ, and ended up taking them out. I saw no performance change after going back to standard lifters. The oil bleed that the Rhodes lifters do drops pressure some, so you have to have a good oiling system.
Stick to a good RV cam. A lot of people here are running the Summit 8600, and like it a lot. Stick with something with lift in the .480-.490 range, duration around 270 and a 112 LSA. Don't over cam, a lot of people do. Bigger is not better. Look at the cam specs, and find one that makes it's peak torque in the RPM range you run in. If you don't have a tach, get one and watch it a while before building your motor.
Bob
tufcj
