Posted By: DaKuda
451 or 470 for street/strip car - 08/30/11 12:28 PM
Both lowdeck setups which would be better for some street use? Also, does anyone make a rotating assembly for either kit that offers regular rings that do not need to be file fit?
Posted By: gregsdart
Re: 451 or 470 for street/strip car - 08/30/11 01:14 PM
The best answer is the most cubes you can afford. With cheap cranks available, 499 or 512 low deck combos get my vote. I have run combos of 475, 499, 535, 528, 446. Given the same heads, more cubes for the street is better.
An example, a 535 with standard port heads will have a torque peak of roughly 3800 rpm max, no matter what you do to it.Pretty good rpm for a street combo, never needs more than 6,000 rpm.
A 512 with the same standard port heads will peak around 4,000. The low deck 512 also gives you a very light assembly due to shorter pistons and small rod bearings.
Posted By: Thumperdart
Re: 451 or 470 for street/strip car - 08/30/11 01:26 PM
I like my high winding 470.............
Posted By: DaKuda
Re: 451 or 470 for street/strip car - 08/30/11 02:51 PM
I'm not interested in running a big stroke in a stock block ever again been there done that 451 or 470 only. Big inches are great but the stock blocks are not.
Posted By: Thumperdart
Re: 451 or 470 for street/strip car - 08/30/11 03:04 PM
I`m at 11+ years w/two different head/cam combos and I can`t kill this thing and believe me, I`ve tried.
Posted By: DaKuda
Re: 451 or 470 for street/strip car - 08/30/11 03:09 PM
I'm a big fan of the 451 and 470. Are there any kits that use non file fit rings?
Posted By: Thumperdart
Re: 451 or 470 for street/strip car - 08/30/11 03:14 PM
Agreed..........it only takes a bit of work or your machinest can fit/file em for ya.
Posted By: DaKuda
Re: 451 or 470 for street/strip car - 08/30/11 03:18 PM
because I have tried it both ways in the past and for what were doing mostly street driving we didn't see any benefit between the two.
Posted By: Thumperdart
Re: 451 or 470 for street/strip car - 08/30/11 03:20 PM
The benefit is knowing EXACTLY where the gaps are taylored to your engine.
Posted By: ZIPPY
Re: 451 or 470 for street/strip car - 08/30/11 03:23 PM
I like my 451, it works for me and (I think) it has surpassed the goal I originally set for it.
The rest of the car not so much, but it's getting there.
I can understand wanting non-file fit rings, depending on what a person is trying to do....for example if a guy tends to use wider than normal ring gaps for the application anyway, there is no reason to start with no gap at all like a file fit....but I could never find any in a 1/16, 4&3/8 bore. I've deliberately got slightly wider ring gaps than usual in mine just for the safety factor....many would disagree with that practice and that's fine, it works for me.
Posted By: Cab_Burge
Re: 451 or 470 for street/strip car - 08/30/11 06:27 PM
Bigger is always better, ask for non file to fit rings when you order the kit
I would also ask for standard tension oil rings
Posted By: Anonymous
Re: 451 or 470 for street/strip car - 08/30/11 08:47 PM
I second Cabs idea on std tension oil rings for the street--I LOVE a 451 CI--I believe it is one of the all time better Mopar combos--they are easy to build--rev like a chainsaw--they don't care what rod length is in there--shelf stock pistons everywhere! Do a 451 and never look back--you will love it!
Posted By: MIKES_DUSTER
Re: 451 or 470 for street/strip car - 08/30/11 10:56 PM
What would be the cost difference between a 451" and a 470"?? Ive thought about selling/trading my SB for a 451" or 470"
Posted By: DaKuda
Re: 451 or 470 for street/strip car - 08/30/11 11:00 PM
451 has a very light rotating assembly. 470 is even lighter using offset ground journals and bb Chevy rods.
Posted By: ahy
Re: 451 or 470 for street/strip car - 08/31/11 03:26 AM
On cost, If you have a decent 440 forged crank for a core and a competitive machinist, the 451 made from a 440 crank can be lower cost. Same comment on rods. If you have a good set of standard dimension 440 rods, that favors the 451. The 470 uses a chevy style rod. If you are buying all new, there's little if any cost difference.
They are both good... it comes down to matching heads and picking your power curve. The 451 will want to wind higher than the 470 other things equal.
Posted By: viperblue72
Re: 451 or 470 for street/strip car - 08/31/11 09:18 PM
The 470 will give you a little more compression with a flat top piston. The piston would be lighter per a given length of rod, but I think the 6.535 rod is optimal for a 470 which is also cheaper than a chrysler rod. The 3.9 stroke also takes a little out of the radius of the crankshaft which arguably helps the strength. My machinist quoted me 150 more dollars to offset grind. Being the chevy rod is cheaper the price comes out close.
Posted By: viperblue72
Re: 451 or 470 for street/strip car - 08/31/11 10:59 PM
JohnRR,
Good call! That piston canbe used for either 451 with 6.76 or 470 with 6.70.
Posted By: Thumperdart
Re: 451 or 470 for street/strip car - 08/31/11 11:11 PM
My 470 combo uses the 6.385 rod fwiw.
LOL
