The cranks between gen 3 and gen 4 are the same part number if all the rods you use weigh the same it's the same stress on the crank as gen 4

Someone sell this guy some speed🐌

It's crazy your mentioned this because I remember being 5,6,7,8 year's old and rolling with my older brother around to all his friends garages and they all were building their own small block's. Sending the bare block out and just reassembled them using the stock crank and all of them forever having as you say a time bomb. Then just do it all again. Love this video. Truly priceless information.

Paul Harvey ???? Nice info but 15 minutes to say what could have been said in 3 minutes, lol.

Valid piece of information to help with engine longevity. It doesn't add that much to cost of rebuild

Yes my truck is running gen3 block gen4 rotating assy with 16psi loves it

In your particular case of turbo charging an engine, the "heavier" rod would actually be preferable for the sake of strength/durability. As long as the rotating assembly has been statically and dynamically balanced, rod weight should only affect low-end acceleration and then only minimally. The extra stresses turbo charging an engine puts on connecting rods are something auto manufacturers have taken into consideration, as evidenced by the use of heavier rods in early draw-through turbo applications. The Corvair went to a larger displacement, 145 to 164 C.I., in late '64 and saw an increase in rod size/weight. Physics doesn't discriminate.

Great video thanks for the knowledge

I switched to Gen IV rods and came up with similar weights that you got by using a postal scale. I was told by an experienced engine shop that more than 5 grams would throw the balance out. 30 years ago I threw together a 350 engine, and it had a vibration in it around 850 RPMs. Couldn't keep the belts on the water pump, and alternator, the bolt on yoke on the transmission kept coming loose, and the oil pan bolts wouldn't stay tight. It turns out that somehow I used a 305 crankshaft. Even though they have the same stroke the bob weights are different. Can't remember exactly but it was around 1850 for the 350, and 1900 something for the 305. I had my 6.0 engine balanced because of the weight difference, they added weight to the crank to balance it. Being that we didn't have the alignment fixture for the relucter wheel, weight was added to the flywheel/ flexplate because the relucter needed to be removed. They made an alignment mark so I put the flywheel back in the same place, hope I never need to replace it. The moral of the story is Get your engine balanced! When they balance the rods, a special fixture is used so they can weigh big end separately from small end. One is rotating, and the other is reciprocating, 100% rotating, and 50% reciprocating

Great video

What I don’t understand is when you look up reman crankshafts 99-04 they are all the same part number even with the cross over year with floating rods.

you have to weigh the pin your changing as well. from a machinist, drag racer, shop owner of over 30 years. LS is different breed for sure with many possible combos. even this old machinist had to learn many a lesson about the LS platform

Awesome video.

Great info

While the total weight may be different, you're not considering the dynamics of the rotating assembly. For example, the big end of the rod is rotating with the crankshaft, the small end is not..its motion is linear. There is some cancellation of the weight difference of the big ends due to the fact they oppose each other even on a cross plane crankshaft. The kinematic motion of the piston/rod assembly is likewise cancelled due to opposing throws, so there's more to this than simply weighing the rods and saying it's a big difference.

You could probably find a whole gen4 short block for less than the cost to balance your assembly. I understand you get vr wheel issues but it's really something to consider, especially because the bushed rods need captive piston pins.

Weigh the ends

The Lighter the rod without sacrificing strength, the better off the engine is at all speeds.

I have gen 4 rods in a gen3 motor/crank with a turbo. over 4,000 miles. Yes, you will have weird engine vibrations from doing this. anything over 2700 rpm for me starts to feel like a medium driveshaft vibration but its actually the motor.

I've done it on a 5.7L LS1, But got her rebalanced as I give it death every time I drive it. She's hits 7500rpm all day every day for 4 yrs an still going strong NA of course & she's killed 3 4l60e trans so far. 4l80e going in her very soon just have another 2k to save up.

I agree

My question is this , if your swapping out rods and pistons and the weights are within spec across the 8 used in comparison to reciprocating balance then why not ? or are you saying that because the rod / piston combination of the stronger set up is that much heavier that you will some how damage the crank or the bearings designed for the stranger rod / piston combination am I missing something here ...

Matt from sloppy mechanics says he's swapped gen 4 rods and pistons into gen 3 blocks using gen 3 cranks without balancing the rotating assembly.

This is good stuff! Do you have a video of Pistons/Rings/Pin+++ ?

I'm trying to find a way to make a 5.3 out of a 4.8. the internet only has testimonials.

Which way do the dimples face in the engines??

Ok I understand your point but did u weigh out every single rod and piston and calculate the difference across the board with a complete rotating assembly

Did you think to take in the bushing in the gen four rods? Take them out then weigh it

I have a question...could I put a gen lll 5.3l into my gen lv with a 5.3...and if so what would I have to do. I've heard change knock sensor location and reluctor wheel

If I can get 4.8 pistons and rods can I just swap them in after switching the rings or do I need to do anything else

do you think aftermarket piston and rods have this same issue? im trying to bore my 5.3(gen 3) to a 3.820 bore im looking at gen 4 rods and aftermarket pistons on a gen 3 crank as a possibility also looking at summit racing forged piston and rod set on a gen 3 crank

If all the pistons and rods are the same weight I don’t see a problem... so what happens when you put after market h beams and aftermarket pistons?

I'd say no.

What if you use gen 4 pistons and rods with a gen 4 crank and a gen 3 block? Will there be a balancing issue?

I ran Gen 4 rods in hopped up 5.3 bored .123

Could you consider the weight gained in rods and piston. With a reduction in a flywheel weight?

can you use a gen 4 crank., rods and pistons in a gen 3 engine ?

what if it's just a stock engine? will it matter?

I’m considering checking the ring gap on the stock lm7. I hope I don’t ruin things by attempting this and not just leaving it in. I have the block opened up to heads and oil pan off on stand. Idk man 😐

I think much more important are weight difference between same con rods. Also some engine configurations do not need bob weight for crank balancing so conrod and piston weight are not very important if they are same weight to each other.

Pistons must be swapped at same time ?

My gen 3 came with gen 4 rods 😎

On installing the gen 4 rods which way do the dots go. I'm rebuilding my LQ9 6.0. Vin N. I need to make sure I installed my rods correctly. As of now they're installed but not torqued and I have the dimples facing opposite one another. So one side like bores 1 and two the dimples on the rods, one faces the front of the engine the other faces the rear. Please correct me if I'm wrong so I can fix this before I start torquing everything down. Thanks.

Don't listen to this video he has no clue of what he is talking about. I'm sorry to be the one to tell you, but unfortunately he does not understand the concept and also does not do math very well and if you do the math he is talking about and trying to do in his head you will find he is not even doing that correctly I'm not trying to insult I'm just stating facts.

Any guesses as to how much material you could safely remove from the small end of the gen 4 rod?

4.8 stroke is smaller/rod longer...had to help a bit.....o.35 inch different...ha

Depends on how accurate your scale is 😂 and that scale is not

So try to find pins that are 40 grams lighter than stock. Lol. Plus you have the weight of the keepers for the floaters which is probably 4-5 grams for 2.

Are 4.8 rods where the Piston connect the same size as the 6.0 rod what I really want to know is can I attach a 6.0 piston to a 4.8 rod

............or just run a gen 4 crank that’s already drilled for the heavier gen 4 rods and call it a day.....................

lol 11.2 ounces for 8 of them this guy acts like they are pounds heavier lmao. 3/4 of a pound across all 8 rods LMAO.

Too much blah blah blah, and get a different scale if you’re gonna try and prove weight.