LQ4 swapped with LQ9 pistons

@Crazed Performance Repair

I just thought I'd let you know. I watched one of your videos about cam bearings and how the cam catches when you remove it..

Then you talked about race bearings and how the one set was narrow compared to the other.

I'm going to attach an image of bearing info from King Bearings and they actually make "wide" and "narrow" sets.

Also some food for thought about bearing materials.

I always use Aluminum Bi-Metal bearings as that's what has been stock in A LOT (not all) new cars since the mid 90s and the "modern" Tri-Metal babbitt/Lead bearings were used starting back in the 40s. Keep this in mind. Engines back then all the way up to the 90s... 100k miles was considered "High Mileage".. 90s and newer, 100k is considered "Low mileage" now as most new motors will run 200k plus..

Some of that is due to better machining but I think some of it has to do with better bearing material. In particular the aluminum bearing.

I've put aluminum bearings in all the old small blocks I've rebuilt and some of those now have 350,000 plus miles..

A lot of companies will say the Babbitt lead bearing is better for racing because it has a more giving structure for debris. And that's true. Ideally your oil should be clean, but in a race engine the possibility of small particles breaking off of something and making their way into a bearing is much higher than a standard use motor.

The aluminum bearings have a much better wear property than the babbitt/lead.

Also underneath that Babbitt lead bearing one of the layers is copper.

Copper is a soft metal except for when it gets bent very quickly and then it anneals which in my experience that copper annealing is hard enough to damage the crank surface.

When an aluminum bearing fails it usually knocks before it ever gets to the steel backing plate leaving the crank in good condition.

And there are a lot of companies now that are making aluminum race bearings just because overall tests are starting to show the aluminum bearings are just performing all out better.

That was just some food for thought I'm going to post a picture now and if you read the small lines it will even say narrow or wide so on and so forth..

Anyway thank you for getting back to me and I really appreciate your help and your thoughts and your time.

One other thing I would like to know your opinion on..

I'm going to be building an lq4 to replace a 5-3 in my 2000 Silverado.

Definitely not using the 317 heads. Im probably going to use a set of 799 heads and I'm waiting to find out if a friend of mine has a set of flat top pistons and a set of Gen 4 rods which would solve my problem anyway.

The question I had was what cam would you choose for an lq9?

Walking to make as much power possible down low and never plan on going over say 5,000 RPM..

Looking to do some burnouts once in awhile and mainly daily driving and towing..

Was thinking about a BTR stage 2 cam.

Thoughts?

Or what cam would you use to get extra grunt?

@Crazed Performance Repair idk the answer to any. I know from 99-04 they are pressed, then in 05 they are floating like the LQ9. According to the info below they are different sizes. But idk how much tolerance matters for bushed/vs pressed..

Also, I don't have the motor apart yet, so I can only go with the specs I find online, and won't buy Pistons until I get an answer to my question.. so with that said. Here are the details found on Summits website. First for the LQ4, then I'll post the LQ9...

-------LQ4 SPECS-------

-Piston Style: Dished -Piston Volume: +6.7cc -Wrist Pin Dia. (1999-04):

0.9447 in., 0.9448 in. (Pressed) -Wrist Pin Dia. (2005-07): 0.9429 in., 0.9431 in (Full Floating)

-Rod Length: 6.098 in.

------- LQ9 SPECS-------

-Piston Style: Flat Top

-Piston Volume: 0cc -Wrist Pin Dia. (2002-07): 0.9429 in., 0.9431 in (Full Floating)

Obviously the pressed pins would be tighter, but none of the specs say how big the rod ends are, or if they are the same