400 stroker.

[Mopar2You]

Aight.. I have a 1977 400 block sittin in my 77 new yorker with the thermoquad 4 barrel.

I am considering havin the motor stroked with the 451 kit from muscle motors. The question is... how can I tell if the 400 is a thin wall casting or a regular wall casting? I dont want to pull the motor out and find out the hard way that it has the thin wall casting.

The other question is, the kit from muscle motors claims that there is no grinding required, does that mean that the 440 crank in the kit will pretty much slide in? I really dont want to have to have the machine shop grind etc....

Anyone know what kinda power i will be makin with that setup? And will the parts of my 440HP fit on the 400? I have the stuff from the new yorker (its a running car..), will the 906 heads fit?


Thanks for all the help... sorry it took so long. Its difficult to spend that much dough unless I know what I am gettin into.

[jimbo7074]

The 400 you have is a thin wall casting.From 76-78 all big blocks were the thin wall type.I would get the block sonic checked any way,it probably still easily suitable.There was a good article in High Performance Mopar awhile back on cylinder wall thickness.Their findings showed the later blocks were not really any thinner,just the iron used was a little softer than the earlier blocks.

[Jims451]

What jimbo7074 said, the blocks really are not any thinner, the steel is a bit softer, it's not a problem. My 451 stroker is a later block also and I have not had any problems.

The Muscle Motors stroker kit should just drop in, and is already ballanced. Make sure to use the main bearings they supply as the re-ground crank now has filets and the main bearings should have the edges cut for clearance.

Your 440 heads, oil pan, timming chain set and cover water pump and housing, etc should fit the 400 block.
The shorter 400 block uses a narrower intake manifold, a shorter distribitor (but a 440 distribitor will work with the Mopar spacer), the headers should fit, but will be slightly lower, some accessory brackets from the 440 may not work on the 400?

The 451 engine will make about the same power as a simular built 440. The amount of power will depend on the airflow through the cylinder heads, the camshaft size, the intake manifold, the carb size and how well the exhaust flows.

Stock heads with the larger intake/exhaust valves and some porting, with a moderate sized hydraulic cam and 10:1 compression can usually make around 500+ HP.

Bolting on the Edelbrock aluminum heads is an easier way (and not that much more expensive) of getting the airflow for 500+ HP.

[Mopar2You]

so we should have the main bearings cut for clearance? Or you mean the main bearings already are cut for clearance in the kit?

Thanks for the info... I didn't want to rip the 400 out of the new yorker and find out that everything would not work.

Would the softer block be able to handle the 472 stroker as well? My dad thinks that bigger is always better...

[Jims451]

I think the kit comes with the correct main bearings, call Muscle Motors and ask them, they were very helpful when they built my engine shortblock (I supplied the specs for the piston dish volume and deck height and camshaft, they did the rest of the machinework and assembly.)
I don't see any real problem with the 472 cid stroker kit in the 400 block as you are just using a longer stroke, not a larger bore.
In the High Performance Mopar article, they showed that there was not much difference in the big blocks so called thick wall vs. thin wall and that basically any big block that passes inspection is OK to use. By passes inspection, you can have a bad block be it thick or thin wall version. For most buildups with 0.030" or 0.040" overbore it is not a big concern.
Small blocks are a bit different as the later ones do not have as much material in the main webbing area.

I used the 451 stroker because it is much less expensive, and I spent the extra money on good cylinder heads.

There really is no reason to goto the more expensive 472 cid stroker engine if you plan to use the stock heads, unless you are building a high torque, low RPM engine. In other words the extra stroke will make more torque in the lower RPM range, but the heads airflow will limit the peak power of the engine.

[Mopar2You]

thats a good point on the 472 vs 451... I think I'll stay with the 451 and put some RPm heads on it (or what else is good)?

Another question... the 727 on the 440 has a fancy converter plus a manual valve body and its beefed up as well, will all that hook right up to the 400 or will I have to get a new converter or other parts?

What would make it a bad block? Can you tell simply by runnin the motor for a few days (no overheating or bad leaks, or bad noises) too see if its a "bad" one?

is it worth it for the eagle steel or BME aluminum rods? or just go with the ones in the kit? How about the file fit rings?

Thanks for all the help on this!

Have you run your motor on the dyno... or at the track in your car? Any suggestions on what to run (cam, intake, carb)? this car will be mostly strip use, with a lil street use as well (fun to bash the local chubby chebies).

[Jims451]

My car is not very quick, it is a very heavy (#4,150 lbs) street car that is setup for handling, not drag racing so I can not really launch the car hard (usually mid to upper 1.8 second 60' fimes) or it will smoke the tires through first and second gear, third gear too if I try to make it smoke
I have managed to run 12.50's at a bit over 110 MPH (un-corrected) using 3.91:1 gears and some M/T street ET tires. This was ran at Bandimere, Colorado where the Altitude is around 6,000 ft. I'm pretty sure the car would run in the 11's at a lower altitude, but I'm not tring to go much quicker as the car has no roll bar. I don't even have sub-frame connectors which I should put on as the body does try to twist.
I usually launch the car between 1,200 - 1,500 RPM (depending on how well the trac is preped), and I shift at 6,200-6,300 RPM.
I think my initial timming is around 12-14 degrees with 32-34 total timming. I can dial in more advance without detonation, but I haven't seen any extra performance. I think the efficent 'swirl' chamber design of the B-1 B/S heads do not need alot of ignition advance?

I have probbably posted the engine combination many times, but the basics are the Muscle Motors 451 CID short block (with 1/2" oiling modification, and preped factory rods), topped with Brodix B-1 B/S heads from Koffels. The heads have a small 65cc chamber so the Ross pistons are dished to make about 11.0:1 Compression ratio.
The intake is a M1 single plane with a 1,000+ CFM Holley Pro-Series vacuum secondary carb with anular boosters (bought it new on a closeout sale at MadCap, one of the local race machine shops here in Denver.
The oil system is just a high volume Melling pump, and the low profile Milodon pan with 1/2" pickup and a factory windage tray.
I was not sure about the cam, so I went a bit mild with an Ultradyne street solid Roller 284R4 (I think that is the grind?) the 0.050" specs are 251/251 duration on 108 LSA installed about 102 to 104 degrees (Muscle Motors installed the cam since I bought it from then when they built the shortblock.) With the Koffels 1.6:1 ratio rocker arms the cam has a theoretical lift of 0.620" lift on both intake and exhaust. I used Hooker 2" supercomp headers designed for a 440 which seem to work OK on the shorter 400 block when using these heads that have a raised exhaust port. It is still a tight fit. The exhaust system is the TTI 3" with Dynomax superturbo mufflers.
Ignition is a Mallory unilite that triggers a MSD6AL box that fires a Crane ignition coil and goes through Jacobs spark plug wires to the C63YC Champion spark plugs.
For racing this car could use a slightly larger cam, and maybe a bigger intake manifold?
The transmission is basically a near stock 727 with 6 front clutch springs, a 3.8:1 kickdown lever, B&M transPAck shift kit and the important thing, the Dynamic 10" race torque converter (about 3,200 stall and around 4,000? flash stall.)
As I understand it the 'race' converter (about $500-$550) has an anit-balloning plate and HD internals compared to the regular 10" converter (about $350.)

I think if I did this again, I might want the stronger rods for peice of mind, but so far the stock ones have held up.
Also, I think for 600 HP and under, the Edelbrock heads have a good price advantage over the B-1 B/S heads and the Indy S/R heads. Heck, the Edelbrock heads are not much more than re-worked production heads (new valves, guides, hardened seats, springs, retainers, machine work can cost around $600 or more?) and may cost less than professionally ported production heads (usually $1,500+.)
The 440 converter should work, just make sure it is for an internally ballanced engine.
I did step up to the Mopar SFI flexplate (I think it was less than $30) and also a SFI dampner (I think around $200.)
I can't say about the rings, Muscle Motors assembled the engine. On my 360 I built I file fited the rings and it is not really hard to do if you spend the $60 for a ring grinder.
If you need to save some money, look at the Hughes and Ultradyne high rate of lift solid cams. These have lobe profiles almost like my mild roller cam and are way less expensive.

The fuel system for a high HP race engine can get expensive pretty fast.
I wanted to make sure I had no fuel delivery problems as the engine was actually built to be put into a built pro-street car (one that can actually launch hard.)
I'm running a 20-Gallon aluminum fuel cell, a Mallory 500 filter, a Mallory 250 GPH pump (at almost full pressure) to a Mallory bypass regulator up on the intake manifold.
All the lines are #AN-8 to the filter, pump, regulator and back (by-pass) to the fuel cell. The fuel cell vent line is 3/8" aluminum. The two lines from the regulator to the carb fuel bowls are #AN-6.
The engine runs on the street with 91-octane pump gas, but I throw in a 1/4 tank of 110 octane leaded at the track just for extra insurance and valve protection (the lead protects the valve seats.)

[Mopar2You]

da*mn, sounds like you have a VERY nasty setup. Can I borrow your engine and tranny??? Pwwweeeasseee!!! j/k

What kind of car do you have for it to be that heavy?

What would you suggest me to setup the engine with, considering I have a 5:13 dana 60 in the rear with MT street tires (31" tall, 16.5" wide) with a wheelie bar. The battery and fuel cell (nitrous as well) is all in the trunk. I also have a full roll cage. The car is like I said mostly strip, with limited street use (weekends maybe). We'd (my father and I) would like to make about 550-600hp with this motor (we want to run 10's).

Can this motor handle any nitrous at all? If not... that gives me more money to spend cuz I can pull the nitrous setup out. Looks like we are almost definetly going to do the 451 stroker setup. The nice thing about the new heads would be they are aluminum and thus drop some weight. I'm probably going to be running a tunnel ram, and puttin a fiberglass hood on (doin some weight watchers on the car )

Dont know if you missed it... but can I test to see if the block on the 400 is good by simply driving it? (no major leaks or knocks, or bad color exhaust).

Thanks for all the help, its been very helpful convincing my father to go this way (hes a hardcore 440 nut).

What kinda money am I lookin at for the fuel system? I have a 14 gallon fuel cell (6 gallon in the car) and I have a holley fuel pump (have to figure out what it does first).

[Mopar2You]

bump

[Mopar2You]

bump AGAIN...

noone has ANY ideas or suggestions for me???

[Jims451]

I'm not really up on race engines that run Nitrous. I would call Muscle Motors and ask them, they have built many engines like this and they would know.

My Car is a 1971 Charger. It is the 500 trim model with A/C, power disk (front) brakes, power steering, bucket seats, center console, alot of undercoating, the heavy sound deadner under the carpets, all steel (no fiberglass race parts.)