OK, please tear it apart and let me know if I'm screwing up! Also, I have heard that the 1.04 pin is not as reliable as a 0.990, why is that?

This is going into a 1978 F250 4x4, C6, with 4.10's and 35x12.5 bfg's that will be weekend driven and used for towing. The reason I am going this route is that I would like to have the longer rods and by using my 429 crank, I do not have to buy a new torque converter due to different sized pilot holes. Also, I can use my stock intake and 2-barrel for right now. Displacement figures out to be a 429 cid again!!

1971 D1VE-6015-AA ThunderJet 2-Barrel Carb
Center of Crank to top of Deck: 10.32
Stroke: 3.53" (Destroked 4U Crank)
Throw: 1.765
Rod: 6.8" (if they can fit the 1.04 pin)
Silvolite Hyper Pistons 1.76CH, 21 cc dish, 1.04 pin
Deck Ht: -0.005
Head Gasket: 4.5 bore, .041 thickness
Quench: .036
Compression: 9.34:1
Stock D0VE Heads, possibly ported, at least exh bumps removed and intake smoothed up
Comp Cams Extreme 4x4 cam 218/226 @0.05 and .505/.515 lift (summit #cca-35-235-4)
Headers

Eventually I will add roller rockers, edelbrock rpm intake and 625 (possibly 750) carter 4-barrel but just not in the budget right now.

If anyone wants to desktop dyno it, I would be very appreciative. I am wondering if I will lose low end torque compared to the stock 429 by destroking it or if having the longer rods will help make up for that. With the stock 429, it should probably be geared at 3.55.

Thanks!
Duane

 

1.) The selection of 429 pistons suck. If I use them I will have to have them machined down to get the 9.5 compression.

2.) I have passenger car rods and will upgrade regardless. I can get the c8ae's delivered to my door ready to install for $263.71. This at least moves me closer to the 460 pistons. Hence, the question now, who makes a 1.73 or 1.72 CH piston with a 20-22 cc dish. If I can find one of these (which I haven't been able to), then I can use the stock 3.59 stroke or slightly larger.

3.) I can get the 1.76 ch pistons for $135.00. If I figure $200.00 for machining the crank that puts me at $598.71 for the rotating assembly minus bearings. I have not been able to find a kit for close to that amount. If there is one I am missing please fill me in.

4.) Like I said before, no new intake, carb, or torque converter.

5.) I do not need a motor that has the biggest kahoonas around but want one that will be strong and reliable. Not necessarily looking for a big power gain, just don't feel like dropping 4,500 bucks on a motor that will pop the middle out of the u-joint everytime I mash on it. But that may be the route I end up taking. If I am forced to use a 460 crank, I will still use the 6.8 rods with a 1.53 ch, +33cc piston and a stroke of 3.94 with zero deck ht at 10.3 inches.

If this engine will perform as well as the stock 429 2 barrel, then this is the cheapest route to go for a rebuild.

Thanks
Duane

 

This guy sells reconditioned, resized DOOE rods for $200/set with new ARP bolts and nuts.

http://www.dscmotorsport.com/crankshafts.htm

Figure, after freight, that will save you $40 on rods.

Unless you're in an area where they're really scarce, 2Y 460 cranks sell for $75-100 and figure another $75-125 to turn it.

That should put you into a 460 for about the same price as the 429 without the expense of cutting pistons.

Or,

PAW sells a 460 kit with:
Pistons
Plasma Moly rings
Rod/main bearings
Crank/rods/pins

$546 + freight w/cast pistons
$674 + freight w/forged pistons

I don't know what C/Rs are available, but I did use one of their kits several years ago and was very satisfied with the quality.

 

I'm with georgedavila on this one. The more stroke the more torque. Equate more torque with more leverage as in using a long pole to move a large stone or bolder. Short stroke engines can make power but its always at higher RPM's.
My next question would be how heavy a load are you towing? If its light loads like a boat and trailer your cam selection and wheel diameters are probably O.K.
I found even my 460 lost bottom end with a cam milder than the one you listed, and it took dropping the 3:55 gearing and going with 4:10's to maintain speed pulling a 9,000 lb. trailer up steep mountain passes and that was with stock tire diameters of 31 inches.
If at all possible I'd turn your 429 into a 460, purchase a rebuilt converter for a $100 or so and add bolt-ons such as headers, carb, etc. as your income allows over the next year or so. Deen

 

I plugged you engine into DD and horsepower peaks @ 5,000 rpms producing 429. Torgue peaks @3,500 producing 514 lb/ft.

 

Thanks BigJake86!

Was that torque curve very flat? Actually, those numbers look better than I thought they might. The big problem I have run into is that the rods are 2.2" on the big end and the crank is 2.5". That is a lot of meat to take off of the crank!

Thanks again
Duane

 

If you give me a few more specs I'll send you a more accurate graph or just the info.
-valve sizes
-cylinder bore size
-cam lobe center
-int/exh duration
-combustion chamber cc
I redid the dyno and I must have screwed up something the first time. Here's what I found the second time around.
It produces over 300 lb/ft from 2000-4500 rpms, peaking at 395
HP registered 356@5500rpm

 

You'd have to check with someone to find out if the big ends are wide enough, but a set of Mopar 6.768" 440 rods and a 429 crank turned down to 2.375" journals (but keep the stroke stock) would be able to use 460V8 compression height pistons with their pin bores opened .054". Mopar pins are 1.094".