View Full Version : Ford Big Block 385 series versus Ford Small Block 351W engines weight and balance
I am In the process of deciding on Ford BB versus Ford SB engines for my Roadster build . I would like to ask the members of the forum if the weight of a 460 CI engine is significantly greater than a 351 with equivalent gear box, clutch, accessories etc and If so does this adversely affect the handling?
Do the coil overs have to be adjusted to suit. I can see from various photos that there is plenty of space in the engine bay.
From looking around the various aftermarket suppliers I see that heads are about $2000 for the 460 CI. I only want around 400hp, considering that, Is there a cheaper route to go . What size (cfm ) carb would be required? . Do the forum members have suggestions for head, carb, inlet and header combinations. Thankyou.
edwardb
07-31-2015, 11:06 AM
First welcome to the forum. According to this post over on the other forum, a 385 series big block is going to be about 200 pounds heavier than a 351W. http://www.ffcars.com/forums/2229791-post11.html That's alot! But also in stock form, so changing out iron parts for aluminum is going to reduce the number. But that would be true for both. Would you notice the difference? Depends on what you're using the car for. Driving around as a street cruiser, maybe not. Start tracking or running auto-x, most would agree the extra weight isn't desirable. Yes the coil overs would have to be adjusted for the extra weight. But that's normal for setting ride height. May take heavier springs though. Plenty of room? I guess that's a matter of perspective. Yes a big block fits. It is tight though. I think there are way too many variables to start giving specific recommendations about heads, carb, intake, headers, etc. At this point it's going to be opinions at best. Unless you're really set on saying you have a big block, with only a 400 HP goal, I would recommend small block. Either 302 or 351. Both can hit that number easily.
68GT500MAN
07-31-2015, 11:29 AM
I have driven a roadster with both engines in them. The weight difference is noticeable when moving slowly and trying to park, etc. Once up to speed the big block feels a little (slower) in steering response. In my opinion, power steering is a must for a big block car! Welcome to the forum.
Doug
chopthebass
07-31-2015, 01:16 PM
I can't see the point of a big block if front end weight is going to be detrimental.
skullandbones
08-01-2015, 03:54 PM
GeeM,
You haven't mentioned the uses you have in mind for your roadster. If you just like the straight line performance and sound of the BBF then that's going to be an easy choice. Personally, I see many more down sides to having one, especially, if it is not purposefully build for say drag racing or the wow factor you get at a car show or meet (that's hard to beat). This machine does so many more things like carving turns and nimble handling with the right weight distribution. You would loose some of that with the BB. High on my list is the ease of working on the engine and maintenance. Just simple things like getting to the spark plugs and working on the valve train (removing valve cover bolts) can be complicated by a larger block. Things start to get in the way! I have had numerous BBs but they were Chevy. But the problem is similar. Pulling and replacing a big block is more tedious. You should think about all the things that will happen during the life of your roadster. I would vote for the 302/351W with what ever displacement number you need to get the 400+ hp. BTW: I would go with the Holley or Fast EFI with a dual plane manifold.
Good luck
WEK.
carlewms
08-01-2015, 05:27 PM
Welcome to the forum ...
A couple a years ago I went through the same process ... and it can be a bit agonizing.
Like others have posted already you need to decide what is your ultimate objective ...
A car that looks very original to the 427 and your going to keep it off the track/autocross OR
A car that you really want to be a street car, easier to maintain and I IMHO believe easier to build.
I chose a 302 stroked to 347 with EFI. It has the form factor of the 302 with an estimated 420 HP output at the flywheel.
Based on my rides in various versions that is plenty of HP for me ...
Just my two cents ...
Carl
Topfuelhydro
08-01-2015, 06:56 PM
I can offer my experience as I have had both types of engines in the same car. I don't do any road racing or auto crosses but I do the "Tail of the Dragon" which is 318 curves in 11 miles quite often. I had a 302 with about 300hp and no power steering. I recently installed a 504 cu in engine with 685hp and no power steering and today I took it to the Dragon for the first time with the new engine. The 504 and trans weigh about 250lbs more than the 302 and T5. I could tell a difference in the steering in the corners and the handling of the car. Was it detrimental to the drive? No but there was some noticeable difference mostly on the decel in turns. As soon as I got back in the throttle the front end got lighter and the differences went away. For street driving, cruising and the curvy roads I drive I wouldn't take anything for the big block.
Steven
44099
44100
CraigS
08-02-2015, 07:21 AM
Do a stock 351 and buy only pistons w/ a little more compression.Use stock rods and crank. Buy an Edlebrock power package.
http://www.edelbrock.com/automotive/mc/power-packages/top-end-kits.shtml
Scroll down to see the two packages for a 351. Notice their hp figures are at only 9.5 compression so easy premium pump gas.
RCJones
08-02-2015, 07:37 PM
Thats a Chevy link...but don't forget the Edlebrock Clevor. Thats the one I'm building
Gents
Thank you for all the valuable advice, I am always amazed at the kindness and public spiritedness on the forum.
I have decided to go the 351 route after some thought based on parts prices/ availability and the weight / handling/ accessibility Issues. As this will be the first car I have built and although I am a professional engineer I think I will keep the expertise needed to manageable levels.
One day soon I will be harvesting a 351W/ 5.8L roller engine from an unsuspecting F250/ E250 In a junkyard somewhere in Louisiana / Miss and carrying It home in triumph. I like the Idea of fitting an Edelbrock performance package In conjunction with flat top pistons and a rebuild kit.
I notice that a lot of the junkyard F250's that I see online have the manual 4 speed trans . Is It feasible to fit the whole engine/ clutch/ transmission package from the F250 or would the gear ratios be ridiculously low. Could this be compensated for by a high ratio rear diff? Thanks again.
Jeff Kleiner
08-03-2015, 11:06 AM
Don't use the truck 4 speed.
Jeff
CraigS
08-04-2015, 07:44 AM
RC scroll down!