bassackwards

Working on a 383 and installed a new cam. #5 rod made good contact with the rod. I just installed a new timing set and retarded the cam 4 degrees because it was going to need it anyway and now the rod clears the cam. Am I good to go?

AlkyIROC

What part made contact, a rod bolt? I'd use different rod bolts.

Very few engines need retarded cam timing. Straight up or advanced and many street cams have 4* of advance ground into them to give them better bottom end power.

I spin my race engine to 7600 rpm and the cam is installed straight up.

bassackwards

The rods have bolts going up through the cap then into the rod. It was hitting on the shoulder where the top of the bolt would be if they came from the top down.

My cam is a little smallish but it was free and my wife will not let me buy another so I have to use it and retarding was the best answer for being a little small.

My engine is being built for 1000-5000 rpm and going into a 4x4 truck

Orr89RocZ

iTrader: (20)

sofakingdom

iTrader: (1)

This is a VERY common problem with strokers, in general.

Details depend on the SPECIFI rods you used. Like just about everything, some fit better than others.

THIMK about what happens to cam timing as things age...

Does a timing chain ever "shrink"? I've heard of some pretty weird stuff in my day (not least, my own self) but I've NEVER heard of that.

Meaning, NO MATTER WHERE you install your cam TODAY, TOMORROW it will be SOMEWHAT RETARDED (no offense intended all you disabled people) from where you originally put it. Therefore: if you ADVANCED it to get it to clear, it will CERTAINLY wear itself into disaster, as the natural chain "stretch" (which is actually WEAR of all the pivot points) occurs, which of course inevitably retards the cam. Cams NEVER "advance" themselves, they ONLY "retard" over time.

All the same, 4° of change is not enough to GUARANTEE UNCONDITIONALLY that the cam will ALWAYS be safe from contact with the rods. My personal gauge for stroker motors is kind of a no-brainer, mostly because I'm uniquely qualified for such things, since I have no brain... I take a medium tie-wrap (for electrical stuff) that's about 3/16" wide and about .050" thick, and use that as my clearance gauge. I move ALL parts around when I find them getting close, and verify that UNDER NO CIRCUMSTANCES, they will EVER contact. In the case of cam/rod interference, that means, I find where they get the closest; then I hold the crank still and move the cam as far as it will go in both directions from wherever it happens to be as I'm building it; and measure the clearance. I move the cam front to rear in the block and measure the clearance. I move EVERYTHING around against all its constraints and measure the clearance. All 8 intake lobes if they're the constraint, all 8 exhaust lobes if it's them; I never "assume" ANYTHING about such matters. If it ever gets EVEN CLOSE to interference, I look for ways to fix it. IMO what you have described is a recipe for disaster when the unexpected happens; over-rev, downshifting into too low of a gear, a wreck, etc. Personally I would not install a motor that is as you describe into my own car.

AlkyIROC

Then you definitely don't want to retard the cam timing. Retarding the cam timing moves the power band upward a few hundred rpm (high rpm drag racing). Advancing the cam timing moves the powerband downward a few hundred rpm. For a low rpm 4x4, you want to make torque and power down low so you want the cam timing advanced. Without knowing the cam grind and if advance is already ground into it, your best bet is to install it straight up.

Without knowing the cam grind a "free" cam is a paperweight.

The 383 will already make more torque than a 350 with the same cam. A good cam designed for low end torque should be used in a 4x4.

Kingtal0n

I agree with sofa that you shall not depend on timing setting-related to resolve parts conflicts as this.

Also consider that as the engine moves and absorbs combustion energies and spins high rpm all of its internal parts flex a little (deflect). Everything is elastic so you need 'extra space' for those elastic properties

HINKSON AUTO

What rods are you using. You must not be using a stroker rod ?? A lot of the cheap kits don't use stroker rods and can be a problem.

Rods 1, 2, 5, 6 have to be checked