Im putting together a 355 supercharged smallblock using the factory 1 piece rear main seal. I wanted to know what is the limit in terms of power can be made before the stock block starts to get flimsy. I was thinking about getting the new GM sprorts man block for 1 piece rear main seal, but the price is one factor. The motor in question has a stout bottem end with Being fed by an ATI.I plan to run 12-15lb. And am shooting for 600 crank hp.But I want to be able to turn it up if I choose.Thanks

 

Do a partial block fill if you are worried, but in general you should absolutely no worries with anything less than ~1,000hp.

Rich

 

The generally accepted max was about 1100 crank hp. But now that BigRick's turbocharged 'bird is going low 8s at nearly 170, that rule might be changed a little bit....

 

they said that was with only a "950ish rwhp" tune, not the latest 1200+rwhp tune

 

Thanks for the replys.But only thing is Im planning on using the 1 piece rear main seal block from 86-92 not the LT1. If 900-1000 is the limit why would anyone use the Bowtie?My feeling were this. I have to buy the block from my builder at $250. He has to machine it and go over it. And If I wanted to upgrade the caps you are talking atleast 500+ for caps and machine work. Thing is the Bowtie sportsmans comes with a finish bore of 3.98 and doesnt need to be decked or anything like the stocker, plus it comes with angled caps.Im looking at 1000- 1200 for block and machine work if I go with aftermarket caps. Sportsman comes with this already but the down side is I have to get a custom ground cam with bigblock bearing lobes and use aftermarket hydrlic rollers for the cam which can be expensive. The bottomline is I dont want to dump alot of money into a stock block.Thing is I thought the outer limit of the stocker was around 600hp. I just want to put it together once and be done with it and not have to worry about block integrity since it will be street driven, and It is very likley I will be upping the boost in the future since I have the JE pistons with the 52 series .180 wall pins and oliver rods with WSB bolt upgrade, so bottom end integrity is not a problem. How many here have Bowtie blocks?Thanks for all replys

 

yeah Ricks did NOT make it through the weekend. I was pretty bummed. I wanted to see 7s!

 

You asked what hp the block was good for, not if it made more sense to build it up vs. buying the Bowtie or an aftermarket block. Sounds like the Bowtie, or equivalent, would be a good choice for you.

Rich

 

You mean it blew up?!!!!!!

 

Sorry If I wasnt more specific.But I think my concerns go hand in hand with each other.I dont know why I have the 600hp stock block limit in my head, but I thought that was the limit. Has anyone here split or cracked the stock block pushing over 600hp? What I should have asked in posting this thread was if investing money into a stock block to handle x amount of hp would be better off spent on a bowtie.Thanks for the reply.

 

The HP limit has to do with a lot of things, type of power (boosted vs. N2O), filled or unfilled, how good the maching is on it etc.... but basically a block is good for about 1100-1200hp maybe a bit more but it's still a time bomb. Rick's 950rwhp was in that 1100-1200hp range, i've had a customer tell me his NuTek bottom end let go at 1130hp, so I would say 1000hp and your going to be inside the thing checking everything is the limit.

Since you are playing with a SBC it only makes sense to me that you would use a Bowtie, Dart or World block. The Bowtie Sportsman is a good deal, but the 8320 Steel Caped CNC Bowtie is even better. On top of that a 375 cube motor would be a great blown/turbo platform (4.125" Bore x 3.50" stroke) and that block would still have tons of cylinder wall in it, perfect machining and more strength than any filled block would get you. Bascially it's going to take you the $$$$ to get the stock block up to that blocks specs and you are still going to have a weaker unit.

Oh on top of that the priority main oiling is just a little benefit to help take the power.

Bret

 

Thank you very much for the informed reply. Im leaning towards the 1 piece rear seal bowtie since the crank I have is one piece rear seal. I think the block comes with nodular iron splayed caps. Im going to be running the stock stroke and 4.030 bore also. but it will be fed by my ATI. Im just sitting back reading and wow,those are some impressive numbers on the stock block. Im wondering how much was put into block prep to get those blocks to hold together under that kind of power. I wonder if it is up in the bowtie block price range. If I do plan to go with a stock block how much wall thickness should I look for?Or in other word what is the recommended thickness i shoudl have? And what in terms of block prep would I expect to do? Just a note it will be street driven so I am weary of running block filler as I dont want to run hot. Would straight Oliver caps and arp studs be enough for the bottom end, or will the stock 4 bolt caps with studs work well?Thank you for the replys.

 

Well most of them have blown up in that range.

Figure to get a block that is prepped as well as a Bowtie it costs about the same amount if you include the price of the block.

Block fill is not going to raise the temps too much anyways and if you do run a stock block the smallest bore you can put in there is the best, like a 4.010"-4.020" bore because it gives the most wall thickness.

BTW don't stick with a 4.030" bore on a Bowtie, please. 4.125" pistons are the same price and your heads will love you for the head flow. Plus that block can go to 4.190" so no need to worry about wall thickness.

It's Big Blocks but the same things apply.


Bret

 

HPE left their cars outside overnight at the track and they think somebody sabotaged a few of them. Rick's turbo was messed up. They got a new turbo in the car and have dyno'd it again. Before Thunder they were pulling a bit over 950rwhp. This time they are over 1200rwhp Anybody want to guess what that is at the crank? The car has a glide and a 9" with 30x10.5 tires.

 

Oh ok... thank goodness. I was a bout to be real sad..... LT1 block over 1200rwhp is awsome. I've always believed that the LT1 would go further with a turbo over a SC.... seems like they are a little easier on the block and bottom end due to less torsion and harmonics.

Go get those 7s Rick!!!!!! wait a minute.. if he gets there, would that mean the fastest LT1 would be faster than the fastest LS1? (or LS_ variant)

 

If a rod goes out the side of the block it still didn't hold the power.

Anything over about 900hp is going to be a motor that you have to look after like a two year old walking around on the freeway in LA if you want to use a stock block. Unless you get off yanking motors in and out of a car and checking the rods and bearings and everything else I wouldn't go that route.

I'd love to see him run 7's, probably would have cost less money to do a Bowtie block from the start though.

Bret