This is not a third gen related question but you v6 experts might be able to give me some help. I bought a 93 s-10 blazer with a 4.3 CPI in it off a buddy of mine for a couple hundred. The body is in great shape but it does not run. He said it developed a rod knock as he was comming home from a ski trip, and then it just quit. I have been told that these motor have a knock sensor and will shut down before any damage is done to the block. Is this in fact true? If the block is in good shape i would like to rebuild this motor, which leads me to my next question. I can's seem to find a straight answer on this. Are 4.3 connecting rods the same as a 350? Ive been told that the 305 and 327 are not, but that the 350 is infact the same. What is the true facts???

 

No the engine will not shut down.

The purpose of the KS is to retard the timing, due to pre-igntion AKA detonation. A rod knock would also trigger the the KS and then the ECM would would then retard the timing, but it does NOT shut the engine down.

You'll need to pull the engine and tear down. You'll probably find you need a new block, especially if this one is seized (you didn't mention one way or the other).

 

thats what i thought about the KS, someone said that it would shut down the motor and i had never heard of that, just wanted to make sure. could it retard the timing enoght to where the motor would not run? im not sure if it is seized because i havent even picked it up yet, the deal just went down this week. do u happen to know about the rods though?

 

Sorry, don't know for sure, so I didn't say anything about them.

What I have heard or read is that they are the same as any latemodel SBC, in dimensions, 5.7" long, .90" (or so) small end, 2.25" big end, but I can't verify that 100%

 

ok thanks...if you know anyone that might know, send them my way

 

sbc rods are not the same as 4.3 rods they have diff crank side diamiters
sbc rods
Chevrolet Small Block 327, 350, 400 large journal- 2.100 crank pin/.927 piston pin
4.3 rods
Chevrolet 4.3L V-6 262 c.i.- 2.250 crank pin/.927 piston pin

 

the knock sensor only retards the timing a little bit it wouldn't keep the motor from running for sure it might have spun a rod bearing if it did might be able to safe the block the 4.3 is a 350 with 2 cylinders cut off use the same pistons and water pump will bolt up

 

thanks for all the help