I am getting ready to freshen up the 400 small block that is in my Camaro since it has wiped two cam lobes in the last year. I don't know what is causing this, but I figured that a complete disassembly and inspection is warranted this time around. My motor's specs are in my signature.

I am thinking of getting my Trick Flow heads ported, maybe even the intake too. I also want to up the compression a bit, I currently have 9.8:1. Finally, I want to add a hydraulic roller cam.

I haven't made my decision on components yet so I have a few questions. First, this engine needs to be streetable, and it needs to run on 93 octane fuel. I have never installed a roller cam before so what should I watch out for when choosing and installing the cam? Are there any brands that work better, last longer, etc? What will I need to change my motor over to a roller besides, a cam, lifters, pushrods, and valve springs? What dynamic compression ratio should I shoot for and how good does the DCR calculator work when figuring out if an engine will run on pump gas or not?

Currently, my engine is .040" overbored. It has about 10,000-15,000 miles on it. Can I get away with just having it rehoned? I really don't want to bore it any further. Is there anything else that I should watch out for?

Your main concern after wiping a cam will be the bearings and oil passages. If the cylinder bores look good maybe you could just do a quick dingle-berry hone to break any glaze and re-ring it.

I doubt it will need boring with only 10-15k on it. Look for signs of the original bore and cylinder hone -- you should still be able to see a cross-hatch pattern and there should be no ridge at the top of the cylinder bore. Scrape ony carbon off prior to pulling pistons to avoid scoring them.

I'd pull the bearings and look at the crank journals real good to see if any metal from the cam made it through the oil pump and filter. New bearings are a must IMO and a good cleaning of all the journals.

DCR is a good tool for predicting what cam will work with what compression ratio. With aluminum heads I'd shoot for about 8.3-8.5:1 although if you want to push it, you can sometimes get a little more out of it. I am running 8.6:1 DCR on pump 93, but wouldn't recommend going that high unless you plan on the full line of detonation reducing tricks.

For a roller cam the key is following the cam manufacturers directions and spring recommendations. You will need a thrust button on the front of your cam to keep your cam from walking in the block. You also want a cam with a cast distributor gear so you won't chew up your distributor gear. Don't use a bronze dist gear -- they wear out fast.

I plan on going completely through this motor. The block will get inspected and thouroughly cleaned by me and by a good machinist. I am definitely going to install all new bearings. The crank will get inspected too.

Since I am thinking of upping the compression, I will probably need new pistons. Will I have to get the rotating assembly rebalanced when I do this?

You will not regret going roller. I had the same deal...wiped a cam, said never again and will never go back!

A rebalance will depend on how much difference there is in the weight of the new pistons. In the grand scheme of a rebuild, a balance is cheap insurance. You are building a motor to run for years, so don't cut corners.

The roller stuff is $$$. I just bought a complete retro fit kit from Comp for $777. I did spring an extra $12 for a roller bearing thrust button.

The hydraulic roller cams are supposed to be compatible with all distributor gears. I ran mine for one season with the old cast gear but this winter I put in a melonized gear. When I pulled the old one it looked fine though.

Same deal on the fuel pump pushrod if you use one. I bought the bronze tipped unit.

Have fun, you're gonna love it! graemlins/thumbsup.gif