Smitty, that makes me sad, because I can see it being true. It's why I love my old truck (I was 6 months old when it rolled off the assembly line) and want to keep it running.

It's been great working with this guy, and I do hope he's doing well at his business. They're hard to come by, and I respect that.

 

On another note, I called up Clifford Performance on the pistons and the guy was adamant that if you shave 0.040 off the block and 0.060 off the head and use stock pistons that it gives you a 10:1 compression with 160 cylinder psi. I told him I'd done the math multiple times and was only coming up with around 8.8:1 and he said to check it again. They'd done it almost 1500 times. I know my math isn't wrong, and I came up with what the machinist did, so I'm not sure what to think of it.

He also said you want the dish or you'll get detonation problems with the 300.

Otherwise, I spoke with the machinist this morning and had a good 30 - 45 minute discussion about the pistons. I can get some custom ones made for about $500 and get exactly what I want.
But he said otherwise, if we went with bushing the connecting rod, it would require converting to a floating piston (which I'm not fully familiar with what that means or entails). He also was having no luck finding bushings to do that with.

Thoughts?

 

Alright, a little more discussion with the machinist. He was being rather generous with the head when he was shaving it down to 70cc chambers. However, with calculating in Clifford's 0.060" off the head, that's around a 64cc chamber. If they feel there's enough material to go that far, we can easily shoot for around 68 - 66cc chambers and easily hit 9.0 - 9.2.

With the Fel Pro 1024 gasket and 0.039" thickness, if we leave 0.005" for the piston height, that leaves around 0.044" quench.

 

Don't believe most of what anyone at Clifford's say!! Do the math yourself to confirm everything!

The only thing required for the floating piston pin conversion is:

1. Having the bushings installed in the rods.
2. Getting pistons that have the floating pins. On a floating pin, it is retained by a spiral lock type of snap ring/cir clip that sits in a groove in the piston on each side of the piston pin bore. Nothing to it, easy to install. Once the rods are bushed you could install the pistons yourself. If you wanted to.

 

AB, I was going through the same piston search, and love those that BVA linked to, the 351 iirc, with the 19cc dish. Anyway, I just bought today a set of the old 300 rods, with a .912 small end, to allow me to use those pistons. With a 76cc chamber and .030 off the block, they'll render me 9.00:1 cr. That's perfect for me. It's something to think about.

Ford 300 CID. Connecting Rod. Forging # C5TE. 1965-68 Part #R15160

Pin Type- PF

P/Pin Dia.- .9122

C/C Length- 6.206

I paid $110, shipped.

 

I would try to take as little material off the head as possible. Considering all the work and expense to prep a performance head I'd want to make sure there's plenty of head left if it ever needs to be milled flat in the future. A block will need to be bored, honed, etc. so the cost of machine work is a given, if you've overdecked it you're just out the cost of a block. Recreating a ported, tapped-for-screw-in-studs head would be a total drag.

For $500 I think I could live with the CR being a wee bit higher or lower than my target (preferably higher). Custom pistons are obviously the ideal solution, but probably overkill for a DD/trail rig. Perhaps a set of $120 OTS hypers, a custom ground cam and a set of custom pushrods instead?

 

Thanks for the advice everyone. And yeah, I'm not taking anyone's word for it as the math is straight forward to do. The one thing I DID forget to ask him is after he shaves the head, how many CCs he has left in the head.

And that's excellent advice one always leaving room for future work. It would suck to have an issue with the head I've put so much work and money into and not be able to shave it down again for future issues.

And F-250, I had thought about that. However, he's already reconditioned the rods I supplied, so that's already $90 in on those. Not that that's a lot when considering getting what I want, but I'm taking it into consideration. Otherwise, that's an excellent idea. I'm curious why Ford switched from the 0.912 to the 0.975 on the 300 after only a few years?

Out of curiosity, where did you find them?

Otherwise, here's where I'm at. If I go with the 22cc pistons. This is with the Fel Pro 1024 head gasket with a 4.18" bore and 0.039" crushed thickness. Leaving the deck at 0.005", and shaving the head down to 70cc chambers.

Volume Contribution (CCs)

Head Chamber - 71
Gasket - 8.77
Deck - 1.045
Piston Dish - 22
Piston O.D. - 1.24

101.033 CCs of head volume.
831.925 CCs for the cylinder.

Head volume: 104.055cc
Cylinder volume: 831.925

Total: 935.98

C.R.: 9:1

That leaves the block with 0.005" on it in case it ever needs trued up as well as not overdoing the head and only shaving it down to 71cc.

Now, if I did track down some 0.912" 300 rods, which isn't a bad idea, I could always sell the ones I have now on eBay as good, reconditioned rods...

 

I found the rods on ebay. A member on the other forum posted a link to them. I wonder if he was the one selling them, ha ha. The thread is '351 pistons.'

I don't like taking so much off the head.

 

Modifications
Built '65 series 300c.i. (around 312c.i. now) I-6 w/ 300 H.P. @ 4600 rpm & 400 F.T.P. @ 3200 rpm w/ a 9.5-1 C.R.
It idels @ 675 & is smooth as glass, a quarter was placed on top of the Valve Cover & it Did Not move Nor rattle @ least on the stand anyway.

Ross Pistons 4.060
Hastings Power Flex Rings .060
Federal Mogul Mains .020 Under
Clevite Performance Bearings Std.
Federal Mogul Cam Bearings Std.
Melling Torque Cam
Melling H.V. Oli Pump
Eagle H-beam Rods 6.300 2.100 Rod Journal
Crane Gold Race Roller rockers
ARP Main Stud Kit, Rocker Studs,
Fisher International Ballancer
Bore 4.060
Power Hone 4.060
Mild P&P Intake & Exhaust
Performance valve job
Performance Balance job on Steele Crank w/ in 7 grams
Grind Rod Journals to 2.100
Plumb Intake for Heat via Water Pump
Deck Block to Square
Align hone to Factory specs
Deck block for Zero Deck
Offenhauser DP Intake
Holley 390 CFM
S.S. Borla 3 into 2 Header
8' of 3" tubes attached to Flowmaster 60's
4 Core Desert Radiator mated w/ the Original Radiator Housing
2 1,200 CPU Electric Fans, on @ 180*, off @ 170* mounted diaginally
PerTronix Electronic Ignition & Coil

 

So what's the squish height? How come you never tell us anything, Flashman?

 

More seriously, with those extra-long rods, aren't the wristpins way up in the ring grooves?

 

I just wanted to pass this along. I found this years ago, and based my build on this one. AB, I don't know whether his numbers are true, but if they are, your numbers should be a higher the larger valves and pro porting. Note the header, not efi's, ha ha.

The hp/tq was done on an engine dyno at the tech school I went to about 6 years ago, the 300-6 was my engine rebuild project. I had the belt on it spinning just the alternator and waterpump.

330ft-lbs. @ 2400rpm (if I remember right) and over 300ft-lbs from 2000-4200rpm. It made 240hp@4200rpm also.

My complete engine build is.
Block
-83' 300-6 block
-bored .030 over
-cut .019 off the block to get zero deck on the pistons
-.040 quench
-Compcams 260H with 212* @ .050 lift .447 lift.
Head
-cleaned up exhaust ports with mild bowl work (done by me)
-port matched offy C to intake ports and some valve unshroding
-Stock valves with compcams springs
-shaved .010 off to clean up the head surface/up compression
Intake/exhaust
-Offy C intake with edelbrock 500cfm
-hooker supercomp headers 1 5/8 primary 2 1/2" collectors
MSD ignition 6t with 2F coil and .055 plug gap

I think thats it, The welding students at the votech had to build an engine stand so I could dyno it.
ran great on 87 octane, my compression ratio was just a touch under 9.0:1 calculated. The .040 quench really allowed alot of timing advance, I ran 14* base timing with 87 octane and stock timing curve. It didn't like running stock plug gap with the stock duraspark and I think I was experiancing spark blowout, the MSD box fixed that.

 

That's some fun info. Granted, I imagine they dyno'd the engine directly, as opposed to in a vehicle.

I'd like to get a before and after dyno of mine, since I'm very curious what the difference will be, as well as how much it'll ultimately make.

 

Ok, another question on pistons.

It's very frustrating that almost NO source lists the piston ccs for our engine.

However, I was looking through Silvolite's catologue (Page 38) and came across these:

https://www.uempistons.com/catalogs/...te_catalog.pdf
Silv-O-Lite Hypereutectic Pistons 3118H-030 - Free Shipping on Orders Over $99 at Summit Racing

The catalog states:

It specifically states that's with a 4.000 piston.

So, doing some reverse math, the only number I can come up with for ccs that would give it an 8.3:1 with a 76cc head and 8.7:1 with a 69cc head is around a 19cc piston.

If so, I could use those with my stock connecting rods and easily hit 9:1 with only shaving my head from 74.4 to 74, and shaving the block down 0.021" (with 0.005" left).

Anyone else confirm this math?

 

Maybe someone can chime in on a quench stepped piston vs. a plain D-cup dish. I've always been a D-cup man...

If you're feeling a little shifty you could order one each of a few 300 pistons, enough to get free shipping from Summit, have them CCed then return them. Just like dusting off and nuking the site from orbit it's the only way to be sure. All you'd be out is the cost of return shipping.

FWIW, I measured an H674P pistons and it was 25cc.