DRAG RACER TRYING TO SELL ME HIS COMPLETE BLOWN SBC ENGINE
 

He is telling me that i wont have any luck using a dart aluminum block ( WHICH I ALREADY HAVE) on blown alcohol or any other aluminum block in this application. He says the mains will have to be redone quite often depending on how much you run it. He is trying to sell me his complete motor that has the motown steel block and says no problem with the mains staying put. IS THERE A POWER LEVEL THAT THE ALUMINUM BLOCK WILL HAVE MAIN PROBLEMS AND AT WHAT HP LEVEL WOULD THAT BE AROUND? I only need around 900 or so and its going in a boat where you really never get a solid bite like on a racetrack. What do yall think? Will it hold u p or not?

topsportsman needs to answer this one. i have never had a problem with using a aluminum block at that power level. the guy is full of chit build what you have and it's lighter for the boat.

We have several turbo engines that make 1700 H.P. all the time with a Dart aluminum block and have never had main problems,Dart and Brodix have the strongest mains in the business.Our Sb2.2 circle track engines make 844 H.P. and run on the average 600 miles between rebuilds and the mains are never out of round,I suspect the guy is telling you this to sell his motor.Bill

The guy must work for DynoFlo and is just tryin to take your $$$

Yah, aluminumn blocks don't hold up. Thats why they use them in an 8000hp top fuel engine, lol.

Frank
Advanced Performance
www.get-ap.com

Those are solid billet blocks also. How many of them will make 500 passes ?

No direct experience myself. I have asked a couple of serious bracket racers ( T/D ) why they dont go to alum blocks and their response was the same. Things start to move around to much when your making 300 passes a year. With that said ... if you dont run that much then you probably wont have any issues with it, so it wont affect you.

i would think if u need 900 hp out of a small block blown engine..either aluminum or iron block will work...i had a small block alcohol blown injected engine at one time....i heard rumors something close to what dcarr was saying in that the aluminum would give to a certain degree (heat/cold)therefore making it a little more tricky for sealing up the HEADS TO BLOCK ...but you have to keep in mind that when this was mentioned the blower was gonna pack 22-25lbs of boost into the cylinders.

i assume your boat will be for recreational uses,,being that it will not endure the thrashing a all out race motor will see....plus if the boost stays 10lbs or under you are not gonna face the problem with squeezing out head gaskets etc..if it were not o-ringed to begin with..

i have heard nothing of the fact about mains giving up in a aluminum block no more than a iron block...i am with the other guys..the man is telling you something that does have some merit to it but maybe doesn't apply in your case......

NOW I WILL SAY THIS...it is highly recommended that aluminum rods be used in a blown or NOS motor..for the fact the aluminum rod will cushsion the impact that will reach your bearings....SO i WILL agree that you will stand a chance of changing out your bearings sooner with a steel rod over a aluminum Rod..

Maybe thats what your seller has heard and getting it confused with the mains ????? :roll: :roll:


thanks brian

We are making 2230 H.P. with 36 lbs boost in a 406 cu.in. SB2.2 using Crower steel rods and Federal Mogul V bearings.we have had absolutely no bearing problems or failures. Aluminum rods shouldn't be used for any endurance application such as circle track or marine,those engines get more cycle time in a 1/2 hr than a drag race engine gets in a lifetime.
A lot of builders have realized that other than top fuel, light weight steel rods will retain there big end shape much better than aluminum rods and expand at 1/2 the amount providing better backing for the bearing.In the last few years we have switched all of our N20 stuff to steel,Its sure nice not to have to worry about the rods when you get 60/70 passes on them, the steel rods run for years.Bill

man thats a lot of stress on such a small motor :lol:
That is interesting stuff there Bill. What kind of rpms is that motor seeing with the steel rods. Just curious here.

Only 7500 rpm on the turbo motor,power falls off after that fairly quick.we do turn our small circle track SB2.2 engines 9200 with 590 G.M. steel rods,our 3.875 stroke SB2.2 runs at 8600 rpm with 611 GM rods and our spec engines 8800 rpm with 440 GM 1.771 rods.
The cup guys were at 10,500 qualifying and 10,000 for the whole 500 miles with 480 GM rods before the gear rule. some of the new steel there using like 300M is amazing.Bill