Danny

iTrader: (16)

I’m almost done with the body work on my 4th gen and now I’m looking to start on the motor. Power will be supplied from a forged L92 fed by twin GT45s (please no flaming) on E85. I’m shooting for anything north of 1000RWHP through a TH400. This is what I’m looking at:

4th gen Fbody (3100lbs)
Stock 6.2L L92 block (mains will be pinned when block is honed)
Stock L92 crank
Forged rods (undecided on what brand)
Forged pistons (undecided on what brand)

There are a lot of guys out there (me included) that believe the stock L92 crank can take over 1000HP so I’m not too concerned about the crank or the pistons/rods. I think my weakest link will be from the block w/ stock sleeves. A lot of people say they’re fine and some say to just get the block resleeved with Darton sleeves. Then I started thinking about filling my block with “Hard-Bloc”. I was thinking a ½ full or maybe a ¾ full will add more structural strength to the liners, helping to prevent distortion. I know there have been a lot of guys that have gone past 1K on a stock aluminum block but I just want to add a little more insurance. To me, it sounds like cheap insurance. I’m all about saving a buck but I think this buck can go a long way. 

1. Will filling the block add the needed strength I need to help hold everything together?
2. What block filler do you guys recommend?
3. Should I fill the block first, let it dry and then take it to get honed?
4. What process do you guys use to fill aluminum blocks?
5. Will a ¾ fill be street friendly with a external oil cooler? (30 miles or so)

What do you guys think? I would like to hear from those who have
experience doing this.

cam

iTrader: (9)

Meh block filler is kinda of a drag race only deal imo. Ive never owned a block filled engine but Ive been a part of building a few and they never lasted very long for one reason on another.

Now regarding your build plans? Im not certain of the max potential of the stock crank but I wouldn't be too concerned about the crank thats not the weak link its the rods first, pistons next, when it comes to boost. Ive seen quite a few builds now with a stock 6.2L short in the 650 whp range that hold together very well. So with a decent set of Callies rods and some Wiseco pistons Id run the stock block and see how she holds up. The Darton sleeves? Meh again.... Sometimes great, lots of times not so great. It really comes down to the machine shop and engine builder at that point.

If your only looking at 30 mile cruises? Keep in mind its not like 30 miles of WOT it'll be a blip here and there and I think the stock block would be fine for that. Just make sure your tune errs on the side of safe so when you go to the track and flog it you dont get any detonation.

If you can keep the tune dialed and good gas in it 1000 whp is within grasp and my vote would also be that it will last with the stock block/crank. Just be sure to do head studs as well as upgrade all the fasteners.

Danny

iTrader: (16)

So you don't think a block filled engine would last long? I wasn't going for a full fill. Maybe 1/2-3/4 fill. I just want to add some strength to the factory liners.

As for the rods and pistons...I'll definitely be going with some proven parts. The Carrillo rods and Wiseco pistons were my first choice followed by Oliver rods. I just want something that'll hold the power without breaking the bank.

The engine will definitely be held together with ARP everything. I was even thinking about upgrading the head bolt holes in the block to match the size that come on the LS9 heads since that's what I'll be using.

BTW, how's the 8.8 holding up? I had one in my previous 4th gen and I'm going to be going the same route, only beefier.

Any other opinions/comments????

cam

iTrader: (9)

Its not so much that block fill hurts the block it doesnt it just impacts the cooling capacity BIG time. Heat messes up A/F which will mess up the tune which can cause alllllll kinds of troubles. What im saying is from what ive seen? The block on these gen IV's is STOUT and id think you would fare better by controlling the engine temps more accurately by not block filling than the benefits of beefing up the block with fill would add. Your treading into theory and experience here where each builder is probably going to do what hes comfortable and has experience with so choose wisely

Havent had a single failure out of one of my 8.8's yet.

Danny

iTrader: (16)

I see your point on the "block filling" theory. I've also read about some guys would install tubes into the block before adding the filler. This way they can retain some sort of water jackets in there and still be able to fill the block for more strength. Personally I've never seen anyone do it or know anyone who's done it. It's just something I've read and it seems like a good idea. The only problem I see if routing the tubes and aligning them in the perfect spot before adding the filler.

On a side note, I've read that a lot of guys who do a 1/2 fill say they don't worry about the coolant getting too hot. They are more worried about the temp of the oil, which I think a good external oil cooler with a fan should take care of.

I'm wondering if anyone has had problems with the stock block/liners at 1000RWHP.

cam

iTrader: (9)

Might want to post up the forced induction section im sure theres guys who patrol over there who know for certain what the limits of the stock block are

tonyturbo42

iTrader: (1)

I can second this. Filling block will VASTLY effect your cooling. Just think about you are you saying. You filling your engines water jacket 1/2 - 3/4 full of solid material. So basically you will get 1/2 - 3/4 less water flow which in turn will cut down your cooling efficiency dramatically. If this is a drag car then who cares. You do a pass and the car cools down. On a street car I never recommend filling a block. Its nothing but trouble.

Danny

iTrader: (16)

Do you have first hand experience with a filled block? If so, how long did you drive before you started noticing the temps rising uncontrolable?