Tell me more about it if you've used it, etc.

Would you recommend running it on a stock block LT1, forged internals 383 on squeeze?

 

What is your projected power level?
The LT1 block is pretty strong and just from what you posted I am guessing you don't need to think about this but if aiming really high you might.

 

I've used this stuff on a 406 sb. There are a couple things you need to keep in mind. Yes, there is hp to be gained. Not only is it good to stiffen up the bores, but it also helps lateral forces that twist the mains around. Do the hardblock BEFORE all machining. I would suggest an align hone as well. You need to run a separate oil cooler if you drive this thing on the street (half fill) because your oil temps will go through the roof. Years ago when I used this stuff, some local engine builders saw up to 20 hp on a full pour. I don't have any info on a half pour but it has to help. It is a challenge to keep things cool for street driving - even with the half pour so you will have to decide if it is worth the hassle. I personally wouldn't use the stuff unless you plan to bore the motor .060 or you have clearanced into the water jacket for a beefy rod. Long arm motors benefit much more from the block pour because of the increased side loading forces on the cylinders.

 

A half fill is not a bad idea IF you are going to put a lot of power thru the motor. We are talking 800+ hp. Some people don't think it's needed for that level, but the bores do move around at that level so it's only going to add life to the parts and power from the better ring sealing.

It's actually better to pour the hard block 1 month before you machine, and make sure you clean everything out of the water passages before you poor. Once the hardbloc sets you need to machine everything in the block, but that's not a problem since the block should be converted to a 4 bolt main.

Bret

 

For hi-po use (on the street) I'm, a big believer in 1/2 fill on thin wall blocks like a production SBC. I have not found cooling to be a problem. As Bret said, hi-po in this context is 800+hp and you need to let it fully set before machining the block. Obviously, for a hi-po drag race setup using a stock block, it's clearly the way to go. I've never seen test results, but I am convinced it makes hp and it may help longevity.

Rich

 

Ok, some good answers here. To answer a few questions I'll be running a forged internal 383 5.7" rods, I don't want to deal with the hassle of a 6" rod. It's going to be a toy, it's not a daily driver but I still want to be able to drive the thing. Cruises, Canyon runs, etc. It's going to be set up as mainly a G-machine. I'm expecting from talking to a few people around 400whp NA. I'd also planned on squeezing for the strait line when I want to go faster This is where the hardbloc comes into play. I had a guy ask me if I was going to run hardbloc, I wasn't sure what it was, he gave me sort of a crash couse of what it was. I just wanted some more opinions, I'd like to be able to squeeze upwards of a 200 shot. I've heard the hardbloc with forged internals will make this virtually bullet proof. I mean I know no motor putting that sort of power out is going to be pullet proof, especially on the juice, but it helps tremendously. I've also heard strangely hardbloc helps cool cylinders better because it keeps the flow of things towards the top of the water jackets. But other people say it heats the motor up big time. And aftermarket oil cooler would take care of this completely?

 

I'd also planned on doing this. I was thinking about getting a 4 bolt out of an impala or 9C1(is that right?) caprice. But a splayed 2 bolt should be stronger right?

 

A mild NA motor (400hp) with a 200hp nitrous shot is not where I'd start to think filling the block would be of any use.

Rich

 

This is prolly a dumb question, but why would a hard bloc application have higher oil temps, just cant picture it in the ol cranium.



David

 

Not atall right. The Impala, 9C1 Caprice and lowly civilian Caprice grandpas Roadmaster or Fleetwood and gasp even aunt Millie's Roadmaster or Caprice wagon got the same exact bottomend as the f-body including the block. The LT1 was standard on the Impala Roadmaster Fleetwood and wagons be they Caprice or Roadmaster, it was optional in the Caprice be it 9C1 or Civilian. I will give you credit for realizing the Impala might actually be lumped in with the Caprice as it is every bit as much a Caprice as a Z28 is a Camaro.
4 bolt blocks were Vettes LT4 f-bodies that SLP put together and warrantied engines. That said if you genuinely need 4 bolt mains IMO you are better off starting with a 2 bolt block and using aftermarket billet caps the 2 bolt will hold a lot more than most are willing to give it credit for, but if dumping this kind of cash into a build IMO this is a better way to spend the money. Weigh the cost of the aftermarket caps against the hassle/cost of a 4-bolt block and consider the billet will be stronger if machined competently. That said guys have run more power through stock bottom 2 bolts than you are looking to make granted they do it with juice on top of boost but still stock bottoms have held it eventually needing pistons or maybe bearings but otherwise holding up well.

 

Well damn, ya learn something new every day, I ALWAYS thought the B-body had the 4 bolt LT1. Also, wouldn't a 2 bolt, into a splayed 4 bolt be stronger than a billet capped two bolt? I understand that the cap can break stretch and all the other good stuff in other places besides the bolt locations. But still, cost to power ratio, wouldn't billet caps cost more than splaying a four bolt?

 

because it plugs your water jackets...

 

Good point. I had my block acid dipped to clean out the passages. I agree with rskrause here. You are really nowhere near where you will see much benefit. Again, I would only use it if I were going .060 or if I mistakenly ground into a water jacket down by the pan rail. My 406 was not a street friendly motor so I had heating problems anyway but I can absolutely tell you that regardless of what your temp gauge says, your oil temps will scare you ! You could just get 6" rods to reduce the side loading, and make sure the top piston ring is at least .180 down for NOS. No prob!!

 

A small block 400 is notorious for cooling issues anyway, I have a half fill..I will get it running and see I guess.


David

 

spitfire we are both talking aftermarket maincaps just highlighting a different feature not disagreeing.

As far as the cooling the bottom of the bores while cureently getting some coolant cooling which also helps cool the oil would get no coolant flow with the half fill this will make all the lowerend cooling fall on the shoulders of the oil while also reducing a cooling place oil hits to cool hence the talk of making sure oil cooling is adequate with a half fill.