451 short block ???

Posted By: earthmover

451 short block ??? - 09/07/11 07:19 PM

got a chance at a 451 short block at a good price...want to ask a few ??? on this before i try to pull the trigger...short block has 14.1 comp pistons with 72 cc heads (my heads are 72cc as well) it has a 690 roller,mil gear drive, with billet mains,and studs,good crank and rods..now what kinda power could i see with this motor ..my heads should go 350 with the bigger valves and gasket matched (2.25 val)
-1 with t&d 1.6 rocker,intake i guess i will look for the 400-2 as i have a 440-2 for a 440block with the 2" spacer,buddy has a nice 1150 carb...
all this will be fit to a 727 trans no brake as of now,either 8" 5600 verta or 9.5 5000 verta, in a 70 duster about 2900lbs right now...suspension will be up graded to backhalf ladder bar with coil over and a dana rear..
will this combo get me down in the low 6's in the 1/8 mile without much trouble?????just getting a feel of this before i go ahead and buy the short block thanks mike

Posted By: Bob_Coomer

Re: 451 short block ??? - 09/07/11 07:30 PM

It will run well. It will want to RPM though. Shift points will be 7200+, to make it run half way decent...
Get the a loose converter, and leave the line at 6K will help. Those -1's can be a hair lazy down low in moderate heavy car 3000 lbs+ and usually soft in 60ft times.
I ran a similar combo with CNC ported -1's from Modern, jesel rockers bla bla bla. In a moderately heavy 3400 lbs Dakota... It would 60ft lazy in the mid 1.30's range but run out the strip with killer MPH 114+ (im taking stock stroke here)
The compression will help if its really 14:1.... Even with those tight 72cc chambers the pistons are probably blob domes near 20 CC..
Its just very difficult to get a 3.75 stroke engine to 14:1.. thats all.

Posted By: HardcoreB

Re: 451 short block ??? - 09/07/11 07:32 PM

In short..yeah, no problem. You'll have to spin it to 7,500 or so to optimise the ET. Use the 8" converter.

Posted By: HardcoreB

Re: 451 short block ??? - 09/07/11 07:43 PM

Quote:

)
... Even with those tight 72cc chambers the pistons are probably blob domes near 20 CC..
Its just very difficult to get a 3.75 stroke engine to 14:1.. thats all.

Good point. It would probably run better milling more from the heads and lopping off the domes(the pistons intake pocket will most likely need radial clearence anyway w/ a 2.25 int), provided you have enough P-2-V depth. Honestly, I would consider a custom ground cam for about $200 more.(factor-in selling the current cam)

Posted By: clovis

Re: 451 short block ??? - 09/07/11 07:54 PM

Just a thought

If it is stock block, you may be making more than a stock block will like for very long, especially at 7500 rpms and 14:1. It looks like you have enough head flow and cam to go 700+.

Posted By: earthmover

Re: 451 short block ??? - 09/07/11 08:41 PM

so the -1 will make the shift points out of this world?????maybe i can get this and get my set up going and run some 6.50 and not set it on kill

all the time ...give me a idea of what would be the best way to run this ....im sure there are a bunch of 400/451 guys doing pretty good with this set up...this way i can save some coin for a good block down the road..thanks mike :

Posted By: Mopar_racer_99

Re: 451 short block ??? - 09/07/11 09:17 PM

No problem there we used to run 6.10 1/8 and 9.79 1/4 in a 2900 lb charger with same combo. John

Posted By: Bob_Coomer

Re: 451 short block ??? - 09/07/11 09:22 PM

Keep the camshaft to a moderate size. It would be easy to over cam this one, and not being able to make it up in the upper revs, it will not see.
Id shoot for a cam that would make the good cylinder pressure.
Id look for a cam in the mid 250's to low 260 for dur@50 with as much lift as you can get.
Id use a 6K minimal converter, and 4.56' to 4.88's gears depending on tire height.
I switched over to a toilet setup mid year and that thing really made the power down low. I really like that alky injection system. Easy to tune etc.

Posted By: earthmover

Re: 451 short block ??? - 09/07/11 10:01 PM

good to hear that it can and does work well ...im just trying to get this thing going and be able to upgrade later ,just didnt want to burn cash i dont really have right now..mike

Posted By: 69CHARGERMD

Re: 451 short block ??? - 09/07/11 11:26 PM

Not sure how much of my combo relates to yours,,but thought i would post mine,
(Porter Racing did the motor)

451, tall fill, .055 over
ross dome pistons
BME rods
Ohio Crank 4340 stock stroke
Flat tappet cam 304/304, 272/272, 108 lsa, 650 lift w/1.6 rockers
13:1 compression
Victor intake,
Dominator 1050
edelbrock heads
made 650 HP @7200 and 564 tq at 5800

this is in a 3450 lb Belvedere.

Best ET so far,,(foot braking),,,was a 10.08 @ 131MPH

Posted By: earthmover

Re: 451 short block ??? - 09/07/11 11:56 PM

nice

Posted By: bumps440

Re: 451 short block ??? - 09/08/11 12:48 AM

Quote:

nice

Sound like you want what I had. but yours will be better( easier).

I had 3225 lbs, Ported stage IV 2.14/1.81 lucky if they flowed over 285 or so. . 13.75 -1 tarantula manifold, 4780 carb..( 800 cfm
Lunati roller, 276/284 108 .690 w 1.5s. I used 1.6 harland sharps. 9" J type convertor,( 5200 stall. shifted at 7000 hit the stripe at 7500.
5.38s and 14x32s on 12" rim.

What is your cam?

Posted By: earthmover

Re: 451 short block ??? - 09/08/11 01:40 AM

i got a luntia roll thats 731 lift with 1.6 rockers but i think it has a 690 roller in it now not sure of the specs..mike
but if i could use this to get me through while i get funds for a block ill be ok ..

Posted By: clovis

Re: 451 short block ??? - 09/08/11 03:25 AM

Doug

Did you get a bob weight for your engine from Dwayne?

Posted By: 69CHARGERMD

Re: 451 short block ??? - 09/08/11 08:21 AM

Hi Dwayne, I don't recall a bob weight, I can re look at my papers and see if he mentions it. doug.