Short block selection

**Brandonz28** · 10-21-2013, 11:47 AM

Hi all! I'm new to the forum and am in a bit of a mess. I have a 2002 camaro z28. It has about 85,000 miles on it. I bought it last year and got an aftermarket warranty on it. The engine started tapping a couple months ago so I took it to my mechanic. He pulled the heads and pistons are loose in the cylinders. The cylinders are worn and have a lip at the bottom of the stroke except where the skirt rides. And the pistons are worn, so the warranty company is probably going to pay for a new shortblock rather than rebuild it. They will cut my mechanic a check so its up to me what to do. Should I get another aluminum ls1 or should/can I get an iron 6.0 or something? The car is stock accept for exhaust and want to keep it that way its my daily driver. I ask about the truck block from a reliability stand point rather than performance. My mechanic said that this was a common problem with ls1 as the piston skirt design was bad and that you can't bore the block once its worn only hone slightly. Thanks for your input.

***SMWS6TA*** · 10-21-2013, 12:19 PM

Your mechanic is correct. Most likely caused by piston slap. The sleeves can be honed 0.005" safely, over that and you're taking a giant risk.

I'm in the process of building a iron 6.0 liter.

They are good blocks but much heavier then aluminum ones. IMHO are much better in future build possibilities. They can handle more boost and nitrous if you are into that.

Another positive is that there are many more blocks to pick from and usually cost lower then LS1/2/6 blocks.

Some things to looks for if choosing a 6 liter.

Look for yrs 99'-04' LQ4 or 9's - reason being they have a 24x reluctor wheel and the crank is the same has your LS1. Our PCM (or ECM) runs on 24x, after 04', LQ9's switched over to 58x reluctor wheels. You can swap over the reluctor wheel is all you can get is a 58x, just a PITA to do so or a couple of places offer a 58x convertor box to go from 58x to 24x.

Have a machine shop look over the block. I thought mine was in great shape, turned out it needed a hone job that cost me to get new pistons.

I know you said it's a daily driver, but if you can throw in a 224 or 228 cam at this time you'll get a good bump in HP/trq but not so much that you have to look at new heads/springs/etc....

You might get away running a stock tune but I would send it to Frost to have him get it right if you do get a 6.0 liter.

All your accessories, heads, exhaust, intake...etc will swap over to the iron block.

***SMWS6TA*** · 10-21-2013, 12:22 PM

The difference between a LQ4 and 9 is the piston type. 4's are dish and 9's are flat top. 9's give higher compression ratio.

**Brandonz28** · 10-21-2013, 01:21 PM

Thanks for the info, I'll look into a lq4 or 9 shortblock to see its cost compared to the ls1. I can get a set of aluminum heads off an lq4 or 9 not sure which, should I use them or are my heads better? My buddy has them in the corner of his shop and has no plans on using them. Glad to know everything will bolt up! I read the iron block weighs around 90lbs more. Is that enough to effect handling? Anyone tried it in a camaro or firebird?

***SMWS6TA*** · 10-21-2013, 01:32 PM

gotta know what type of heads.

For stock heads 243's > 241/317's > 853's

If you can get a pair of 243's you'll like 'em more.

Yes many users have done a LQ4/9 swap. Jodi (a member here) just finished her build (copied mine

)

**Brandonz28** · 10-21-2013, 01:40 PM

Are those casting numbers? If so where are they located? Thanks for the info on the cam but I think I'm going to keep it stock, I have an 86 Trans Am also and that's my fast one! I really just want this to be reliable and get good gas milage, stock its still one of the fastest cars on the road

***SMWS6TA*** · 10-21-2013, 01:49 PM

On the heads it will be on the lower left side of the head.

No problem, it's why we are here. Help a fellow enthusiast out.

**Brandonz28** · 10-21-2013, 01:55 PM

I know a good amount about gen I small blocks but feel like a shade tree hick when it comes to these gen III's. Fuel-inwhatchkin! I about died when my mechanic showed me you couldn't pull the lifters without taking the heads off!

**Brandonz28** · 10-21-2013, 01:57 PM

I'll check out those heads thanks! Summit has a short block for 1,700 does that sound good or should I go to the junk yard and buy a block to rebuild. If the latter what's a fair price.

**98TransAmWs-6** · 10-21-2013, 06:36 PM

Originally Posted by Brandonz28

I know a good amount about gen I small blocks but feel like a shade tree hick when it comes to these gen III's. Fuel-inwhatchkin! I about died when my mechanic showed me you couldn't pull the lifters without taking the heads off!

On a side note depending on what your goals are can determine what shortblock you get. I got a ls6 shortblock because I found a 10k mile one for $350 even though I was originally looking for a lq9/4 since the deal was much better. I would definitely heed Scott's (SMWS6TA) advise.

**Mean Green Z28** · 10-21-2013, 06:52 PM

Originally Posted by 98TransAmWs-6

You can pull the lifters without pulling the heads off. You just have to get the rockers off and pull them out with pliers.

No you can't

Also OP has a 2002, so chances are, he should be fine with the heads he has. Check the valve guides and install new seals. If it's his daily, get a shortblock, lifters, oil pump and call it a day! ... maybe throw in a small cam for fun; then he'll need springs, pushrods and a tune.

**2002ssslp** · 10-21-2013, 07:23 PM

Originally Posted by Brandonz28

Hi all! I'm new to the forum and am in a bit of a mess. I have a 2002 camaro z28. It has about 85,000 miles on it. I bought it last year and got an aftermarket warranty on it. The engine started tapping a couple months ago so I took it to my mechanic. He pulled the heads and pistons are loose in the cylinders. The cylinders are worn and have a lip at the bottom of the stroke except where the skirt rides. And the pistons are worn, so the warranty company is probably going to pay for a new shortblock rather than rebuild it. They will cut my mechanic a check so its up to me what to do. Should I get another aluminum ls1 or should/can I get an iron 6.0 or something? The car is stock accept for exhaust and want to keep it that way its my daily driver. I ask about the truck block from a reliability stand point rather than performance. My mechanic said that this was a common problem with ls1 as the piston skirt design was bad and that you can't bore the block once its worn only hone slightly. Thanks for your input.

What warranty company did you use ?

**98TransAmWs-6** · 10-21-2013, 07:29 PM

Originally Posted by Mean Green Z28

Originally Posted by 98TransAmWs-6

You can pull the lifters without pulling the heads off. You just have to get the rockers off and pull them out with pliers.

No you can't

Also OP has a 2002, so chances are, he should be fine with the heads he has. Check the valve guides and install new seals. If it's his daily, get a shortblock, lifters, oil pump and call it a day! ... maybe throw in a small cam for fun; then he'll need springs, pushrods and a tune.

Oh wait you are right. I don't know what I was thinking when I said that lol. Must be sleep deprivation.

**pajeff02** · 10-22-2013, 02:58 AM

This is actually the first I have heard of a totally whipped engine at 85,000 miles. Yeah, there have been catastrophic failures and such with fewer miles, but actually just plain old worn out? Was the wear pattern the same in each cylinder bore?

**Firebirdjones** · 10-22-2013, 05:23 AM

I have seen a couple of instances with these LS engines and piston slap, even with 70k miles, that it's too far gone to correct the egg shaped cylinder bores. .005 won't clean it up and make them round again so it's rendered unbuildable unless you want to spend $1500 or more sleeving it just to make the block usable again. Just not worth it.

That's the biggest reason I won't buy a used LS aluminum engine.

It's unfortunate but based on what I've seen it appears Brandon's mechanic isn't trying to soak him for money. It's just the nature of some of these engines. Once piston slap sets in, you have to wonder if the block is going to be usable come rebuild time.

Personally, the iron block is the only way to go if looking to replace the engine and keep the car for a long time.

***SMWS6TA*** · 10-22-2013, 06:37 AM

OP I would recommend replacing the oil pump, push rods and lifters. If in your situation I would not reuse.

Reasons why:

They already have 80+k miles of wear on them.
They were expose to any metal shavings from the worn selves, pistons, con rods and bearings.
Chromoly Push rods are very affordable. I picked up a set of stock length for $100.
LS7 lifters are now the OEM replacement for all GEN III & IV motors
Because you keeping it as a daily driver the LS6 Oil Pump is a great replacement, not sure if your yr had a LS6 OP or not. Usually goes around $140.

**Brandonz28** · 10-22-2013, 06:40 AM

Yes the wear pattern is the same in every cylinder. The warranty company is protective or something like that my mechanic has the paper work. My heads are 241's my buddy's are 317's are they better ir worse? I think I'm definitely going with the iron block. If I do that and use my heads and cam can I get away without a tune? I don't know anybody that does that. Most shops in my area are all about the imports or are old school carbs and such. Thanks for all the help!

***SMWS6TA*** · 10-22-2013, 06:44 AM

I meant 317's , sorry.

They are a truck head that flows decent. I've seen guys running these with a cam and run pretty well.

**98TransAmWs-6** · 10-22-2013, 07:00 AM

Originally Posted by Brandonz28

Yes the wear pattern is the same in every cylinder. The warranty company is protective or something like that my mechanic has the paper work. My heads are 241's my buddy's are 317's are they better ir worse? I think I'm definitely going with the iron block. If I do that and use my heads and cam can I get away without a tune? I don't know anybody that does that. Most shops in my area are all about the imports or are old school carbs and such. Thanks for all the help!

You are actually near me. I live in Fairfax and there is a great tuner up in Baltimore called Fbody Central. There is another in Richmond if you want to drive or get a mail order tune at Tunebyfrost. As far as what heads to use this is my line of thought, if NA use 241s or 243s and if FI use 317s. Obviously you can use any head for most applications but the FI guys usually want the 317s and the NAs want the 241s or 243s for the different chamber volumes for the different compression ratios. 317s if you are going to stay NA you would need to do significant milling if you want to stay in the 10.6 to 11.0 to 1 ratio. 243s you wouldn't really need to do any if you have flat top pistons and I am not totally sure for 241s.