I was wondering if anyone here had direct experience with putting 351c pistons in a 400. I am planning a build of a 400 and wanted to increase compression with out milling the heads.

 

Welcome to FTE!

Check out this place:

http://www.tmeyerinc.com

 

Yes, you can put 351C pistons in a 400, but you have to bush the 400 rod to fit the smaller 351C pin. However there is no need to use a 351C piston to boost the CR in a 400. The compression height of most 351C pistons is 1.65". This is the same as the compression height of a 400 piston. You can get a flattop Badger piston and get near 9.0:1 CR with stock 400 heads. You can also get a set of pistons from Tim Meyer with 1.717 compression height, and have it dished to get whatever CR that you want.

 

The reason I was interested is you can buy a set of cleveland pistons from summit racing for less than 200 bucks. If I bought a higher compression piston given the low compression smog head I'll be running... I should get near the desired 9.5:1 compression I want. Are the 400 heads 76 cc combustion chambers?

 

9.5 is too high for the open chamber heads unless you run a big cam. Mileage and low end performance will be rotten. Some of the guys here can run dynamic compression ratio calculations.

 

I think I bought my 400 pistons from Tim for around $200 and I think $60 for the rings... its a pretty good deal...

 

A flattop piston with 1.65 compression height in a 400 will give you 9.1:1 CR with a 78.4cc head whether the piston is a 351C or a 400 piston. The Badger pistons hav a slightly lower compression height and produce about 9.0:1 CR. KB pistons has a piston for a 351C with 1.67 CH (KB148?). This will give you about 9.4:1 CR.
Depending on what cam you use this can be done.

What is your planned use?
What cam do you plan to use?

 

I was just going to use it as a driver. Its a low mileage prestine example, but just a driver. Can some one elaborate why 9.5 to 1 is too much compression. Ford does it all the time in the late model stuff with very mild cams. I was planning on using a mild split duration cam, something with a little overlap to give it an idle and still build nice torque. I do not want to kill the mileage or change the converter though. I was planning on using the stock rocker arms, upgrade the springs, using a performer intake with a Holley 600 cfm vaccum secondaries carb w/ 1 3/4" headers. I'd like for it to pull hard with enough torque to turn over the 33's I'm running with the stock 3.50 gear. Is this wishful thinking or what?

 

A mild cam with an IVC of 58 degrees ABDC or later like a Comp Cams 265DEH should be OK with 9.5:1, provided you can use 93 Octane fuel.
A Comp Cams 255DEH will give you more low end torque, but the IVC is only 53.5 degrees ABDC and detonation on pump fuel is likely. The max CR with this cam should be 9.0:1.

 

"Can some one elaborate why 9.5 to 1 is too much compression. Ford does it all the time in the late model stuff with very mild cams."

There's a lot of reasons. Smaller bores are more detonation resistant because of shorter flame travel. Small chambers have quench benefits. Spark plugs are better centered in the chamber for a faster burn. EFI gives more precise A/F ratios to prevent a dangerous lean condition. Computer controlled ignition better manages spark advance and have knock sensors to instantly retard timing if needed. Aluminum heads dissapate more heat.
All of these combined can add up to an engine that can run 1.5 points or more compression with the same grade fuel.

This build ran 9.45:1 compression with a 268 cam. I don't recall what grade fuel was used.
http://www.geocities.com/styleline58/400.html

 

I'm running Keith Black Cleveland piston's in my 400 right now.I deck the block and took a touch off the head's to give me 10 to 1 compression.I'm right at 10.1 to 1.Of course I'm not running 93 octane either.I probably could but I would have to take so much timing out of it that it would be a turd.

 

I have CHI aluminum heads and flattop pistons that gives me 10.3:1 CR. I use 93 Octane with no problems. I just topped it off with 89, since the price has gone so high, still no pinging. Of course my cam has an IVC of 66 degrees ABDC.

 

bringing this back... as pistons for the 400 are a bit more problematic at this point IMO. I have a set of badgers from Tim but the options across the board are wickedly slim. I talked to badger and they have little to offer. TMI had them make some special zero deck but ya can't get those either. Forged are great if you have the $$$.

So I'm thinking a trip into figuring cost of cleveland pistons might be a good thing. How much would it cost to bush the rods?

 

I missed something. Whne did the hypereut taller CH pistons that Tim had made become unavailable?

 

Bill, they were when I tried to get them- said he'd run another batch but wanted to get the forged going- so I'm pretty sure they are not available in 040 and 030 but even if...whats it cost to dish each of them for compression and is getting a hold of higher quality cleveland pistons a better deal or not giving the cost for bushing the rod?

For me thats the question. I have regular badgers (o4o) sitting in my garage but want to check out other possibilities as my pistons may be the weakest link in my build so far.