Anyone have a link/source for all the stock spec's on this engine. The usual, bore, stroke, chamber size, pistons, cam specs, anything I can punch in my dyno program for a baseline. While I know dyno programs aren't all that accurate, they do come in handy for seeing what happens when you change a part. I have everything for the small block six's, but info seems hard to find for the big six.

 

Here are the specs on the 4.9L 300 cid engine from the 1981 factory shop manual, does this help?

 

Big help! Now if I can find info on earlier years to compare chamber sizes on heads.
Thanks ctubutis. Those chamber sizes are enormous compared to what I'm used too.

 

Ford 300 carbed heads 65-86 are 76cc combustion chambers.

The 240 heads have 68cc combustion chambers.

I believe the EFI 300 heads are also 68cc. But they are a fast burn chambers with shrouded valves. And they have a tendency to crack if ever over heated.

 

That makes things easy on chamber size. I'm sure they varied in compression ratio's, everything else did. I'll look up available pistons to see if they made the change like that. Thanks for the info. You'd think someone would have wrote a book on these engines like everything else.

 

I think I know of at least 10 different pistons they used in the 300's. They had different sized and shapes of the dishes in them. And some had no dish at all but had a shorter compression height. They seemed to like to change the compression height on the pistons. Some sit down quite a bit from the deck at TDC.

 

I'm a fan of the Keith Black "UPS" pistons if you are looking for more compression. This piston with a stock 240 head (or the efi head) and you're gonna be in the mid 9's for compression (at least that's what I figured up a while ago when I built mine up.

 

What's the specs on the UPS pistons? What's the compression height and the dish size? Are they hypers or cast?

You have to be careful when selecting pistons. Some of the 300 pistons are a true flat top but the compression height is only 1.576". While others are 1.778" and just about everything in between.

When I build mine I'm just going with some domed 351W pistons. They will require a little work to the rods but they will get the job done. But I'll be shooting for a slightly higher compression then most guys.

 

A friend sent me a copy of the 72 Ford truck shop manuals on CD, so that and the 81's ctubis posted should give me about all I need. Thanks guy's.

 

Need the stock manifold tube diameter leaving cylinders and stock size exhaust pipe at manifold. Got my program calibrated pretty close to "advertised" numbers using all 72 information. Should give me a good ref point for changes. Wish I had that 240 head I scrapped after unable to give it away.

 

The UPS pistons are Hypers, Here's the specs on them.

Hypereutectic. 2.700' Dia. Head Recess .215' Deep W,.055 Quench Step

They are part of the silv-o-lite series, part 3118h. So far I like 'em.

Keith Black quotes the compression on these as 8.7:1, but this is with a stock head. I'm running a 240 head, plus a little decking and shaving. I figured it up as low to mid 9's on compression when it's all said and done with.

So long as you're not going to be running copious amounts of Nitrous or forced induction you really don't need more than a Hyper pistons.

 

Those specs don't look too bad. But I need domed pistons for my set up. So I'll probably just go with some forged 351W pistons.

 

sounds like a plan. Diamond will make whatever you need, or you should be able to run off the shelf ford 400CI pistons. Just giving you options. For the money I had at build time these were the best that I could get.

 

Hi there, you wouldn't have same info for a 240ci engine would you so I can compare rod length and combustion chambers and so forth. Regards hemihaze.

 

Not for a 240 cid, sorry.