what is difference in 393 and 408 stroker?

blueracecar · 05-15-2007

i am going to build a 351 stroker and was wondering if there are any issues that come up like clearaces or anything like that between a 393 and a 408? just wodering seems like i see more 393s at the track as opposed to 408s. its going into an 85 gt that is only a race car not a street car. why not have afew more cubic inches?

Jamesco5.0 · 05-16-2007

I have meet a few guys at other clubs that I'm involved with and they say the 408 is the way to go! One of them has the 408 in a '85 (ironic) and he has been running (street and strip duty) for more then 2 years now. I am kind of still leaning toward the 393 for my build but we'll see. It's only .150 more of a difference in the stroke so why not right!

blueracecar · 05-16-2007

hey i appreciate it if its only .150 more stroke then why are you leaning towards a 393? just wondering. i am pretty sure i will be going with a 408 but i am still going to go and talk to the machine shop this week and see what they say.

superfast91gt · 05-19-2007

more cubic inches no replacement for displacement

94' cobra 351 · 07-11-2007

393 roughly equals 6.4 Liters, 408 roughly equals 6.7 Liters....

I think people go with 393 just because the kits are cheaper

I'm still in debate whether to go with the 393 or 408.... I have seen 351's stroked and bored to 445 which is pretty darn sweet if you ask me!!

I am planning on a supercharged 393/408, should have enough power to satisfy me

kingdavid403 · 02-04-2009

What's going on? I am currently building a 408. When i put mine together i noticed i didn't have to do any grinding or fitting. So i contacted eagle and spoke with a rep. he said ford made plenty of room for up to 410 cubic inches with no additional block grinding. Also he said be thankful it's not a chevy bigger than a 383 or i would be grinding all day. These motors make well over 400 hp in mild very streetable form.

94' cobra 351 · 02-04-2009

Wow, my previous post was pretty misleading... I've learned a lot about stroker engines since then.

Yes, the difference between a 393 and 408 is a .15" more stroke (3.85" in a 393 and 4.00" in a 408) They both have a 4.030" bore, which is about as far as you can push a production block. From what I've read, 4.040" is the max bore you can go within a safe range. Production blocks can be bored to 4.060", but this makes the walls very thin.

There are aftermarket blocks out there than can be bored/stroked to make 460 cubic inches. Dart and Man o War sell some good looking blocks. They are a pretty penny though, ESPECIALLY the aluminum block ($5,000 just for a block!)

I still plan on doing a 408 stroker, with a goal of 600HP. I'm going to use 225cc heads, but haven't decided on which heads yet, I'm thinking AFR.

**RLG34750** · 02-05-2009

Quote:

Originally Posted by 94' cobra 351

Wow, my previous post was pretty misleading... I've learned a lot about stroker engines since then.

Yes, the difference between a 393 and 408 is a .15" more stroke (3.85" in a 393 and 4.00" in a 408) They both have a 4.030" bore, which is about as far as you can push a production block. From what I've read, 4.040" is the max bore you can go within a safe range. Production blocks can be bored to 4.060", but this makes the walls very thin.

There are aftermarket blocks out there than can be bored/stroked to make 460 cubic inches. Dart and Man o War sell some good looking blocks. They are a pretty penny though, ESPECIALLY the aluminum block ($5,000 just for a block!)

I still plan on doing a 408 stroker, with a goal of 600HP. I'm going to use 225cc heads, but haven't decided on which heads yet, I'm thinking AFR.

what a difference a couple years of research & studying will do for you.....

Jamesco5.0 · 02-05-2009

Amazing how time fly's!! I haven't done either 393 or 408 ci. I spent a year or so after that post jackin around with a turbo and have moved on to other things now!!

**EagleAutosports** · 02-05-2009

Well that's what this is for, to gather information.

mmb617 · 02-05-2009

Quote:

Originally Posted by 94' cobra 351

I think people go with 393 just because the kits are cheaper

That was the reason for me!

I went with a 393 because my build blew the budget so bad the couple hundred dollars difference in the short blocks meant a lot.

I see lots of both motors and they're both good. I'm sure the 408 has a little more potential with the extra cubes, but I'm happy with what I've got.

71f100&82gt · 03-02-2009

Hi, if you are wanting a strip motor i would go with the 393. i read an article on the 302 stroker, 331 vs 347, they both had the same cam, heads, intake, blah blah blah, and the 331 made a little over 20hp more than the 347 at a higher rpm, the 347 made just 7 more ft/lbs at a lower rpm. im pretty sure the 393 vs 408 is going to be basically the same outcome. they would probably rev just as high as the other but the 408 isnt going to make as much power as the 393 at that rpm, plus you have more of a chance bending or breaking a rod or the crankshaft with the 408 being that its a longer stroke.
It just depends on what rpm your planning on turning it at.