400-451 advice

[Wicked72]

So im starting to get my parts together for my 451. I already have a 440 forged crank. I was going to build a twin turbo motor but after talking with ray barton they said the crank wont hold up past 650hp for very long. So im just going to build it a budget all motor until i can buy better parts. I want to use my 452 heads but not sure if its even worth it. Id like to be at 450-500hp and i know the heads will be a choke point. What do you think about heads as far as factory for now. Also does anyone have the specs for this build i find random stuff and cant seem to spec a complete build. I need crank journal, rod, and piston sizes etc. As far as cam im thinking something from Hughes.

[LowDeck451]

I'm sure some of the guys will reply but, have you checked out the 'Performance Corner' or 'Proven Engine Combos' threads on this site? Lots of good 451 builds and info about cylinder heads there. 

[Nacho-RT74]

I built a "451" with 452 heads... combustion chamber needs to be equalized, since the flat portion uses to be at diff depth each one. I have got up to 0.025-30" difference in some. Even I already run the engine, is dissasembled once again to make that job getting all combustion chambers depth equalized, then head milled dow to get 0.095-100" depth to get quench, since the some chambers are at this moment around 0.125" depth

If you are building with 400 rods and standard bore, I have standard pistons bore sold for the build. New in the box. KB215

[Wicked72]

How well will the stock rods hold up? I will get aluminum heads at some point. And how are they equalized? Do those pistons need to be machined using the 400rods?

[Nacho-RT74]

How well will the stock rods hold up?

NOT A PROBLEM ON THE BUDGET BUILD. SINCE I WAS ON THE SAME DEAL. YOU CAN GET AFTERMARKET RODS IF YOU WANT ON SAME STOCK 383/400 LENGHT IF YOU ARE WORRIED

I will get aluminum heads at some point. And how are they equalized?

THE FLAT PORTION OF THE CHAMBER BEING MACHINED/GRINDED PER NEEDS TO GET SAME DEPTH ON ALL CHAMBERS, THEN RECHECK IF HEADS NEEDS TO BE MILLED DOWN TO MEET THE PISTON STEP HEIGHT INTO THE HEADS IF NOT, YOU WON'T GET QUENCH

Do those pistons need to be machined using the 400rods?

NO, JUST MACHINED IF USING CLOSED CHAMBERS. THE STEP ON PISTONS ARE CUT TO  MEET THE BLUE PRINTED STOCK HEAD CHAMBERS DEPTH WHAT SHOULD BE AROUND 0.095-0.100 AND USING METALLICK HEADGASKET AND CONSIDERING THE BLUE PRINTED DECK HEIGHT SHOULD GET YOU THE PISTON 0.020" BELOW THE DECK, WHICH TIPICALLY ARE NOT IN BOTH CASES ( heads depth and block height ) THAS HOW YOU WOULD GET 0.040" OR SO QUENCH

[Nacho-RT74]

lets see.

the quench step on KB215s is 0.095 which suposelly is what the open chambers depht must be at flat portion per blueprinted values

the pistons on a correctly decked block must be 0.020" below the deck

you need around 0.040" to get quench

Since stock pieces are not preciselly an art of precision you need to get somehow the chamber depth on around the same than the step on pistons. need to measure all chambers, get everyone to the deepest one, and then cut the heads what is needed to get .095" depth or so.

Lets say, you get all chambers at the final depth of 0.120" cause that's the deepest one ( which is very much posible BTDT ), you'll need to cut the heads 0.025" or so

then the 0.040" quench will be obtained with the metalic headgaskets at nominal 0.020" plus the piston to deck height which on a blue printed block should be the other 0.020"

lot of measures to get.

you can get also block decked at 0 and use composite headgaskets.

that's the deal trying to get quench on open chambers

and that's why allmost everybody try to work on these builds with closed chambers, flat top pistons and 0 block deck height LOL

[BSB67]

Or buy any aftermarket aluminum heads which are both better and lighter than any factory head, and buy a zero deck piston. Perfect CR with quench.  Done

[c00nhunterjoe]

400 rods and pistons and a 440 crank isnt going to work

[Wicked72]

They are different pistons not 400. You get pistons to match the rod and crank combo. I'll have the 440 crank milled and put good fasteners in the rods.

[Wicked72]

400 rods and pistons and a 440 crank isnt going to work

I want to do that but not in my budget

[c00nhunterjoe]

By the time you pay to machine down a 440 crank mains to b motor journals, cut the rod surface, polish and  rebalance, you can buy a brand new 4340 crank. Same thing with the rods. Machining cost to resize then balance is pointless with the cost of a stroker kit. For a budget stroker build, look up 440source. 2000 will get you a comete rotating assembly. Pistons rods crank and bearings, arp bolts. Done.
http://store.440source.com/Stroker-Kits/products/3/

[PRH]

It you're really on a budget, just find a 440 block to go with that 440 crank.

IMO, it's not worth the cost/effort of doing a low deck 451.
If I'm going to the trouble of building a stroker.....  I want some real cubes out of the deal.
A 489 out if a 383, or a 511 out of a 400 for me.

[Nacho-RT74]

400 rods and pistons and a 440 crank isnt going to work

I guess he meant the KB215s when asked ? No you don't ned to cut KB215s except if using closed chamber heads.

You need to measure and cut everything else ( as described ) to get quench  but the pistons.

[Challenger340]

You don't have to actually "machine" the counterweights down on a 440 Forged Crank to fit in a 400 Block, we never did back in the late70's/early 80's when we were doing them before anybody even knew what a "451" was ?

Yes, you do have to Machine the Mains down to 400 Block sizing, which just removes the factory rolled fillet and strengthens the Crank at that point....
but,
all the actual counterweights require is a 45* Chamfer application along the outer counterweight edge(Angle Grinder)
then,
utilize a 1/2" carbide Ball and radius the Block main web beside the Cylinder @ bottom..... the Crank will clear just fine.
It's definately more work... but hey, if you are on a budget ?

I forget what year ARIA's actually started offering the prior custom Piston as the "off the shelf" S7751.... early 80's or thereabouts ?


here is what a stock 440 Crank looks like prepped for a 400 Block / 451

[c00nhunterjoe]

You don't have to actually "machine" the counterweights down on a 440 Forged Crank to fit in a 400 Block, we never did back in the late70's/early 80's when we were doing them before anybody even knew what a "451" was ?

Yes, you do have to Machine the Mains down to 400 Block sizing, which just removes the factory rolled fillet and strengthens the Crank at that point....
but,
all the actual counterweights require is a 45* Chamfer application along the outer counterweight edge(Angle Grinder)
then,
utilize a 1/2" carbide Ball and radius the Block main web beside the Cylinder @ bottom..... the Crank will clear just fine.
It's definately more work... but hey, if you are on a budget ?

I forget what year ARIA's actually started offering the prior custom Piston as the "off the shelf" S7751.... early 80's or thereabouts ?


here is what a stock 440 Crank looks like prepped for a 400 Block / 451

What is the real world cost for a machine shop to do that today? Including turning the rod journals .010.
Also, what is the cost on prepping stock rods? I havnt done it in years so this is pure curiosity on cost to rebuild vs buy a rotating assembly

[Nacho-RT74]

Yes, you do have to Machine the Mains down to 400 Block sizing, which just removes the factory rolled fillet and strengthens the Crank at that point....

What? Does that mean the mains needs to be hardened somehow?

Dunno If I understood that wrong

[Challenger340]

What is the real world cost for a machine shop to do that today? Including turning the rod journals .010.
Also, what is the cost on prepping stock rods? I havnt done it in years so this is pure curiosity on cost to rebuild vs buy a rotating assembly

I have NO IDEA what many "so-called" Machine Shops would charge these days ? I think actually FINDING a competent M.S. nowadays that would know HOW to do much of this may be hard enough all by itself ?
Ask them what surface "plasticity" is in metal ?  Is you get blank stares ? WALK AWAY !

Best guesstimate... at OUR Shop ?
* an extra $150 US on top of the Crank Grind ($225 US) to go down to 400 Main Sizing with an .080" radius filet
* an extra $150 US to Beam & re-harden the Rods OVER the Re-Size and set Brg Clrc & Pin-Fit ($150 US)
* Block Clrc and Crank Chamfer ($300 US)
So Total I guess around $975 done this way for "stock" Crank & Rods ?

But here's the Kicker....
Go WEIGH a 4340 451 Crank Compared to a stock 1053 440 Forging ?
and
with the 1053 Cranks and LY Rods NOT having any issues we've seen ~600 hp... they also DO NOT seem to hammer the #4 main as hard with a 50.5% balance factor sub 6700 rpm? (for some strange reason) compared with a 4340 Crank ?

NOT advocating this route anymore, because we are most certainly are too lazy nowadays with NO TIME for it, just say'in.... for the DIY guys who wanna try on a street deal ? it can be done, that's how we did it 40 years ago ?

[Challenger340]

Yes, you do have to Machine the Mains down to 400 Block sizing, which just removes the factory rolled fillet and strengthens the Crank at that point....

What? Does that mean the mains needs to be hardened somehow?

Dunno If I understood that wrong

Just that grinding the 440 Crank DOWN to 400 Sizing on the Mains removes the "rolled" Filet(dip at either end of the main Journals), which is typically where cracks start.
By grinding the 'rolled' Fillet out in the process of going down to the 400 sizing, a "radius" or nicely 'curved' area off the end of the journal onto the cheek can be applied, hence LESS prone to cracking(stronger).

[Nacho-RT74]

got it!

[c00nhunterjoe]

What is the real world cost for a machine shop to do that today? Including turning the rod journals .010.
Also, what is the cost on prepping stock rods? I havnt done it in years so this is pure curiosity on cost to rebuild vs buy a rotating assembly

I have NO IDEA what many "so-called" Machine Shops would charge these days ? I think actually FINDING a competent M.S. nowadays that would know HOW to do much of this may be hard enough all by itself ?
Ask them what surface "plasticity" is in metal ?  Is you get blank stares ? WALK AWAY !

Best guesstimate... at OUR Shop ?
* an extra $150 US on top of the Crank Grind ($225 US) to go down to 400 Main Sizing with an .080" radius filet
* an extra $150 US to Beam & re-harden the Rods OVER the Re-Size and set Brg Clrc & Pin-Fit ($150 US)
* Block Clrc and Crank Chamfer ($300 US)
So Total I guess around $975 done this way for "stock" Crank & Rods ?

But here's the Kicker....
Go WEIGH a 4340 451 Crank Compared to a stock 1053 440 Forging ?
and
with the 1053 Cranks and LY Rods NOT having any issues we've seen ~600 hp... they also DO NOT seem to hammer the #4 main as hard with a 50.5% balance factor sub 6700 rpm? (for some strange reason) compared with a 4340 Crank ?

NOT advocating this route anymore, because we are most certainly are too lazy nowadays with NO TIME for it, just say'in.... for the DIY guys who wanna try on a street deal ? it can be done, that's how we did it 40 years ago ?

[PRH]

I would only even consider using stock rods for this type of build if the desired power level was, well...... Below the amount needed to justify building a stroker in the first place(let's call that 500-ish hp).

Using Bobs pricing, it's $375 to do the crank, plus the cost of the core crank if you don't already have one.

So, for $375-400 more you can buy a new 4340 crank....... And for zero dollars more than that it can be a 3.90 or 4.25 stroke.
If you go with either of the two longer strokes, then you're using BBC rods, which are usually a little cheaper.
All 3 combos can use the exact same piston, the cost is the same for that part of it.

So, assuming you're trying to make enough power to justify building a stroker in the first place(which means you should be using aftermarket rods), to added expense to go from a 451 with a reworked stock crank to a 511 with a 4340 crank is about $400.

That will be the cheapest gain in power you will find in a build like that.

[Wicked72]

As far as the machine cost its not much for me.The cranks are said to only hold 650hp at the max(lucky) and thats from Ray Barton. It will be an all motor setup and i figure i would go with 440rods. Not sure if the 6pack rods are worth getting? I was thinking of going with 915 heads but then again going with aftermarket heads later ill have to build the motor anyway to handle the power i would get from them later so maybe sticking with the 452 will work fine until i do another motor. Im not looking for anything fancy right now. Just something fun to build. Cheap and a little power to boot.

[justcruisin]

Don't waste your time looking for 6 pack rods, they only add weight. Stick with the LY rods if your going OEM. From memory going from a 6 pack rod/piston combo to H-beams and forged pistons I dropped around 500 grams on the bob weight for a 3.75 stroke 440.

[Wicked72]

On factory 452 heads i don't think ill put out enough power to break anything. I can get factory 440 rods for $80 from Tony Mopar. My machine shop is going to work my crank completely for $240 and i only paid $75 for my crank.

[Nacho-RT74]

plus a nice set of the piston like the ones I'm selling LOL.

However, they are for 400 rods, not 440, soooooo... you could keep your stock 400 and save those $80

you asked about camshaft. I installed a Crower 282HDP and is powerfull. Very streetable and nice lumpy iddle to still keep A/C

also got a MP 280/.474 that I could sell too ( was not thinking on that, but needing money to finish my car ). Box got wet for long time, and camshaft got some rusty holes on front journal. Polished and even holes are still there, won't hurt anything. I just changed to the Crower because the 112º centerline makes it more streetable allong with less duration at .050 on intake ( per what I have learnt reading here ). A friend of mine had the MP cam on his 400 with KB240 pistons and was to much lumpy to my purpouse.