I am needing some advice for a motor to put in my mud truck. I found one for sale locally. It is a 393 stroker 351w engine. It has a new eagle cast steel crank 3.85 stroke, rods are Eagle ibeam forged steel with arp bolts kit, the pistons and ring kit are speed pro hypereutectic pistons, and the block has been bored 30 over. It has a comp cam 248int 254ex @ 50 duration .614 .621 lift, gear timing set, roller rockers, roller lifters, arp bolts, professional products harmonic balancer with adjustable weights, edelbrock victor junior 225cc runner heads, and super victor intake.

What i was wanting to know is: I have a 77 f150 with a 351m in it. Will the 393 be a better motor for mud racing, and what kind of hp and tq i might see out of the 393. Plus he wants 2500.00 is that a reasonable price?

 

Well here's answering a question with a question! Are you happy running your mud truck with the engine SCREAMING at high RPM? If that's you're driving style then that engine should serve you well AS LONG AS you don't expect any low and mid range torque. You need to buy some really low gears to go with that engine.

 

I have 33 tsl's on the truck what gear ratio would i need for that motor? Would that motor make 450 hp?

 

not sure if you know it or not,but you will need to change the transmission if you go with the 351w as well,the bell housing bolt patterns are different.

 

What rpms would it make its most hp?

 

He is also selling a transmission with the motor too. It is a turbo 400 with an aluminum racing bell housing to fit Ford small block, and a stall converter.

 

That's a potent package.. I'd wager it's up around 500hp at 6000rpm. I'd run a DesktopDyno sim but I'd need complete cam specs or a grind number to get meaningfull results. Here's a 393 with the Eddy Performer RPM package which uses smaller heads and a much smaller cam...

 

Here are the cam specs http://www.compcams.com/Cam_Specs/Ca...?csid=920&sb=2
part # 35-722-8
The only problem I am having with buying it is trying to find an adapter to join the th400 trans to my ford np 205 transfer case. I found some but they want $600 for the kit.

 

I hate that it's under 400ft lbs at 3k-4k RPMs

I don't know a whole lot about mud 'racing', but is it really going to help having highend power? I imagine most people build for lowend.

those torque numbers in the lowend for a $2500 motor is sad in my opinion.. you could build a 351m into the 350 ftlb range for much less. That looks more like a drag engine I'd drop in a mustang or something

TMeyer, Inc. Precision Automotive Machining check that out.. don't even stroke it to 434, stroke your 351m to 400 ,get the compression up and you're still pushing 400ftlbs no problem at the same low ranges that 351 is at 300ft lbs. it wont spin fast, but it was never meant to be a race motor.

edit: hey, im not saying it's a bad deal at all.. but in a 3 or 4 speed auto? I just dont think I'd do it for your particular application. I'm NOT bashing the motor at all, it would murder people at the strips. Flat out embarass new Camaro and Mustang owners

ok, i don't know what mud racing is, im probably talking out of my rear.. so, take everything I say for a grain fo salt, i'm just an extremely opinionated person that likes torque and hates high RPMs in an american long-stroke engine.

 

I think it'd be good for mud racing, since you would be WOT spinning the tires all the time anyways. But it seems overkill for just 33" tires. You wouldn't need that much power to keep the tires spinning with those little things, but still.. it's a screaming motor.

Don't expect to idle around and it be smooth, or don't expect to go rock crawling with it, it'd be a challenge with the lopey idle it will have. Well, you do have an auto, that helps with the lope.

But all in all, this engine is designed for WOT operation, so it depends on how you want to drive.

 

Agreed. It's no problem at all to get up around 500ft/lbs out of 400 cubic inches all it takes is the right cam, and that kind of powerband is much better suited to a truck IMO. Here's a 408 combo I did for someone else...

 

but to be fair, if he's only going to be running this engine hard and fast, the 351m/400 is not suited for that at all.

 

Just make sure to put some silicon on your oil dip stick that goes into the block. Mud likes to flow in there. Trust me its not fun!

And i wasnt even that deep when it happened.