i have done some searching here and am unclear with the out come so i want to ask right out. are there any flat tops for the 400m, i want to bump comp. up a little what do you guys recommend? also i have read the the later 400m's have crappy cam timings for emissions, will and aftermarket cam fix this? or do i need something else also? i am taking this engine to a shop to be built, what do you guys recommend for a good streetable motor, i have an intake headers and 750 carb already, i know the carb is a little big but it was free and new. what should i have done to make this all work? this is in a 77 f150 4x4. thanks!

 

you can use 351C pistons, or dynagear used to/might still make them for a 400.

 

Dynagear, Ohio Piston makes a flat top that is 9.5:1 cr. If you cant find them, any piston for a 351 Cleveland will work, but you have to use bushings in the rods. A good cam and double roller timing set, timed straight up will really wake your engine up.

 

what bushings on the rods do i have to use? are these bad or something? where is a good place to get a double roller timing set?

 

I recently had the 351 Cleveland piston, 400 rod thing done. You have to use a bushing in the rod ends because a 400 has larger diameter pins than a 351 Cleveland. Ask your shop about it before you start, some shops won't do it.

I used KB Silvolite pistons with 9.5 CR with 76cc heads.

While you're at it, have the rods trued and install stronger rod bolts.

A RV/ towing or mild street cam with roller timing chain will be a nice addition. 400s have big valves, you won't need a lot of cam. Have the exhaust side of the heads ported to get that hump out. The intake side is usually good enough not to need any porting.

You can get the cam, chain, etc. from any good performance part stores or look online.

 

Here is a pic of a bushed rod.
Bushed Rod

Here is a pic of a KB149 piston that was hung on it.
KB149

After FlyCut and before clean up.
KB149a

David

 

nice pics david

 

GT40man:
Thanks!!

Say, what cam are you running in that average 400C???

David

 

crower cam 151174 289/295 .550/.547. runs good with 351c 4V valves and a high cr.

 

Nice Cam.
Looks like it preforms better than the Comp cams 292H we are using according to Dnyo2k...

David

 

what would i need to do to get a good running 350-400hp 400 i already have a set of headers and holley 750 carb.

 

a decent cam and the 2.19/1.71 vavles.

yes david, i ran a lot of cams on dd2k to get the right one, i also have 4v heads

 

Hello all, this is my first post.
David10, I appreciate the pics about the bushings/pistons for the 400. I plan to do the same to mine soon.

One question though, why did you do flycutting? My understanding was the 149s would fit open chamber heads just as they are.

Thanks for any info.

Russ Sheehan

 

Welcome.

The bushings worked well. We were very pleased.
I believe that it is possible not having to cut the pistons if you don’t get carried away with the cam lift and don’t mill the heads to much. But, if you are going to all that work to put in 8cc’s of dome then why not get really carried away!!!!
In either case you MUST check both the Heads for the lift you want and the Piston to valve clearance.

On that Motor we were using a Compcams 32-234-4 (292H-10) advanced by 4 Degrees. The Cam already had 4 degrees in the grind, so that was 8 degrees total. ( The more you advance the cam the smaller the valve to piston clearance becomes). The cam has a lobe lift of .3235 plus the Crane 13744 rockers yields a total lift of .550
The heads were Re-Man D5AE-A2A - 1978 and have both Single & Multi-groove stems. They were milled .025 during the re-man. ( Had to sort through the stack to get two with the same amount of mill) The valve guides were cut down and were modified for positive valve seals. Then they were fitted with crane springs, retainers and valve lash caps.
The Pistons ( KB-149 ) have a compression height of 1.67 That yields a deck clearance of .047 or moves the piston .020 closer to the valve.
Using a safety factor of .100 beyond minimum valve to piston clearance we needed an additional .065. So we had to fly cut them.

Hope that helps to explain it…

 

Thanks David, that does explain it well. What did you end up with for compression? Y'know, theres some weird coincidences going on here. I have a set of 1971 351C 2bbl heads on my 400 that I built a few years ago and I just cannot remember whether the valves are single or multigrooved (old age plays hell with one's memory). I seem to recall seeing both types.
It's an issue because the Crane spring/retainer kit I just bought warns about using the correct retainers depending on whether the valves are single or multi grooved. So, KB149s, Crane spring/retainers, and I also have a 1984 F150 4x4! (insert twilight zone music here).

Anyway, back to tech stuff, did you make your own bushings? What did you use for a interference fit dimension between the OD of the bushing and the rod pin holes? Is that an oil hole I think I see at the pin side of the rod in your picture?

Sorry for all the brain picking...

Russ Sheehan