My dad has a 78 F250 4wd with a 400, auto, 4.10 gears, and 33 inch tires this is his work/hunting truck. He uses it to plow snow, haul a back hoe and to go hunting in the rough so it don't get a lot of miles. Last Thanksgiving as he headed to the mountains he got about 30 miles down the interstate and it started knocking so he drove it home on the back roads to keep the rpms and the knocking down. Well we finally got the engine out and it has spun #1 rod bad and the rod was almost cracked in half and one cam bearing was paper thin and fell out upon removing the cam. This engine only has a little over 100,000 miles and the bore looked good. The trans was rebuilt a few years ago and one head was redone during a hunting trip and last year he had a timing set installed. it started running real bad after that and we let it sit for a while before we found that the dist housing was broke and was letting the cap rotate back and forth, installed new dist, carb was bad from sitting, installed a rebuild holley 2 barrel. Now that you have some of the history I'll get back to the rebuild. We are getting a crank kit from Napa $174. Boring the block .030", one new rod, engine kit from summit $254 (pistons 7.9:1, rings, bearings, oil pump, gaskets) having the one head that was prevously rebuilt checked and the other one rebuilt. I want to shave the heads to bump up the compression. How much needs removed to get close to 9:1? This truck has the stock exhaust manifolds and single pipe. I don't know if the timing set that was installed keyed for 0 degrees or if if just the stock 4 degree offset. First ? if I cannot tell by looking I need to buy a 0 degree timing set? Right? Where is the best place to get one? I'm looking at the cam and lifter kits from summit also (sum-k5200 262/272 dur .484/.510 lift or sum-k5201 276/286 dur .509/.509 lift) $89 Next ? has anyone used these cams which one sounds like what we need? We are also running the stock 2v intake but might upgrade to a edelbrock alum in the future. Does this sound like I'm on the right track or am I missing something?

 

First off, if you have not already ordered the engine kit, DON'T. With their engine kits, they are not returnable. The reason I say not to is that this is your opportunity to build this engine with some spunk by using Badger flat top pistons rather than their engine kit. Your engine bearings will come with the crank kit, so that would have two sets anyway.

By using the flat top pistons in the rebuild you will overcome the biggest obstacle in building a good 400, lack of compression. The flat tops will take care of this. I did mine 8 years ago and could not find such pistons so as a result the engine has been a little disappointing.

I have the Summit k5200 cam in mine and I am quite pleased with it. The other Summit cam might be a little too much cam for what you are trying to achieve. The common mistake that people make in cam selection is thinking that if a little bit is good, then more is better. This can really get you in trouble with a cam.

It sounds like you are on track to build a nice engine. If I could change only one thing from my rebuild it would definitely be the pistons. Don't make the same mistake that I did.

If you have already ordered the kit, then just set the pistons aside and buy a set of the badger 40010F pistons for about $150. You won't regret it.

Good luck and keep us posted on your build.

Have a great day,
Doc

 

The was thinking about the badger pistons this would save me from shaving the heads also. Thanks for the part#. Where is the best place to purchase the badger pistons? Direct from badger or somewhere else? Thanks!!!!

 

Alot of this depends on what you want out of the engine and how much you want to spend.If you have a set amout to spend then you can build within that framework. You can get some gain obviously with any of the mods you talked about but there is probably a way to go about it that will allow you to add to it later if you like. First of all any of the things you do may help but with that stock exhaust your still choking the engine. Most times thats where to start, headers and duals. You could still bump the compression up and it would help but the engine has to breathe. The cr that the Badgers give you depends on a number of things. One is how far down in the hole your pistons sit, Mine were nearly .080 down. Next the cc's of your heads. They should be in the area of 78cc if they haven't been cut yet. Here is a calcultor to play with. http://kb-silvolite.com/calc.php?act...8a4c4f13feafcd.
As stated cyl head volume is 78cc, piston head on a badger is 5cc, gasket thickness .041, gask bore 4.1, cyl bore 4.030, deck clearance with badgers .060-.080, stroke 4". I'm having a brain f*%t and can't remember the rod length. The cam demension will depend on you cam. I would look to either a Comp or Crane dual profile cam.

 

tasty offers some good advice, but it sounds like you are faced with overhaul time. For that reason I think the best approach is to take care of the things that need taken care of while the engine is apart such as pistons, heads and cam. After it is back together, then you can beef up the exhaust, intake and carburetor.

If you will poke around on this site, you will find a poster that goes by TMI. He has a machine shop and can sell you the pistons. I believe you can find a link to his site in the 400 Project, It's alive thread.

Good luck and keep us posted,
Doc

 

I would have the align bore checked in the block & the bad cam journal.

 

Get a Cloyes Double Roller Timing set (CL0-9-3121). It will have three key slots. One for 4 degrees advanced, one for 'straight up' timing, and one for 4 degrees retarded(stock setting). You can get that from PAW or Summit or at your local parts house.

Use the flattop pistons and the k5200 cam. You will also need the valve springs etc. for the cam.

If you can manage to get some porting work done on the exhaust ports, and along with headers it will breathe properly.