Shortening SBC Connecting Rods

[Jagdpanzer]

What is the best way to take 0.030" out of the length of a 6.0" SBC connecting rod?
I'm trying to reuse a set of pistons with a shorter 3.760" stroke crank. The pistons were originally for 4.00" stroke crank and 5.850" rods. Piston compresion height is 1.150". Block deck height is standard SBC 9.025"

[bigjoe1]

Cut the top of the pistons


JOE SHERMAN RACING

[MadBill]

Umm... by my math, you can just bolt it up as-is, with a minimum 0.040" gasket (0.045" would be safer), as the pistons will go from 0.025" 'down the hole' for the original combo to 0.005" 'out of the hole', exactly the same as the factory race spec for my BBC, which uses 0.045" gaskets:

Deck = 9.025 minus 1/2 stroke (1.880) minus compression height (1.150) minus rod length (6.000) equals minus 0.005"

[Pontiac_Puller]

Also, 3.76'? That is the stroke of a 396/427, whereas a 400 is 3.75". Unless this is some type of a custom crank job.

[wyrmrider]

dummy up the assembly on all four corners with one rod and piston and see where you are really at
have you deck squared the block already?
I run pistons out of the hole all the time
sometimes use Marine gaskets which can be a little thicker (different catalogs)

[jmwsb2]

Use MLS gaskets. You can get any thickness you need,

JOHN

[wyrmrider]

to answer your question you can rebush the rods
but you should not have to in your case

[Rickali]

Nah madbill has the math right. The other options are too costly and unnecessary,unless you have sketchy cast rods (aka old Ford 351W running 8k on a winged dirt car w/no traction) you should safely be able to run the quench that tight without the piston hitting the head, proper valve relief required however. I've successfully run as little as .025 piston to head clearance without contact on a sm chev, aftermarket rods, thunder car type engine w/8" wide tires on dirt. Turned nearly 8k w/o contact, with numerous customers.

[tenxal]

I'd rebush the rods or cut the pistons (assuming a flat top) before running the pistons above the deck.

The minimum total deck clearance I'll use on a SBC with steel rods is .035.

[Rizzle]

I'd rebush the rods or cut the pistons (assuming a flat top) before running the pistons above the deck.

The minimum total deck clearance I'll use on a SBC with steel rods is .035.

Just run a slightly thicker gasket.

[tenxal]

Just run a slightly thicker gasket.

I do savvy the math.

The original post asked " What is the best way to take 0.030" out of the length of a 6.0" SBC connecting rod?" Now "best" is certainly subjective. I tend to look at long term things with my junk...maintainence, component swaps, etc.

If he's looking for the cheapest way out, a thicker head gasket would effectively acomplish the same thing.

[wyrmrider]

I run .025 all the time, modern pistons and clerances

[kirkwoodken]

For the life of me, I don't know why the rod manufactures do not offer rod in plus or minus sizes. It is no big deal to change bushing location. I never like taking more than the absolute minimum off decks. To have to order SPECIAL pistons, cranks, or decking seems wasteful when changing bushing placement is so simple.

My pet peeve is not being able to get main bearings plated with a .0005"-.0015" metal of some sort to the bearing backs, so main bore holes can be kept in the right locations. Can't find anyone in my area to do this. Seems so simple to me. Or, why don't bearing companies do this overseas? They do a lot of other plating jobs in other countries now.

[bigfoot]

I never heard of using bushing to make rods a little shorter....i have some sb chev connecting rods out of a 400..so they are 5.565 long.....i am using them in a stroker combo....but piston is sticking out too much...can i bush the small end of rod ?

[tenxal]

Like this:



These were done by Crower, according to the owner. Found this pic on the 'net for those who haven't seen this done before.