351w to c-6 with NP205

Smith racing
Posts: 140
Joined: Sun Apr 14, 2013 8:49 am
Bronco Info: 1978 bronco class 3 and 8 smith racing was inspired from Moss Brothers

351w to c-6 with NP205

Post by Smith racing »

Anyone know what it takes to swap a 400 m. To a 351w using a c6 on both with np205. I know it can be done . I just don't know we're are what to look for vehicle and year wise. 400m great motor but ever little after market parts unless there custom. Thanks Smith Racing.
User avatar
Wrightracing.net
Posts: 2199
Joined: Thu Oct 28, 2010 9:58 pm
Bronco Info: 1972 Bronco with an 86 chassis, full cage and Long travel coil-over suspension.
Location: San Diego
Contact:

Re: 351w to c-6 with NP205

Post by Wrightracing.net »

The bummer is that the C6 is different on a 400m to a 351w. The bell housing is not the same and can't be changed. You have to get a small block Ford C6. They were used on 302 and 351w. The NP205 will bolt to the new C6 . Look at 1983 - 1990 F150 and Broncos. There may be other years but I am not sure of which ones.
Rmc
El Jefe
Posts: 6026
Joined: Tue Oct 09, 2012 10:22 pm
Bronco Info: 94 bronco xlt prerunner
Location: IE SoCal
Contact:

Re: 351w to c-6 with NP205

Post by Rmc »

Yup I was going to say the same. You need a sb c6.
User avatar
Mesozoic
Posts: 36
Joined: Fri Feb 20, 2015 9:18 pm
Bronco Info: '79 Bronco: 408C-ZF5-NP205 SEFI-EDIS8; 4" lift, Dana 44/Ford 9" w/4.10s, locked
Location: Tucson, AZ

Re: 351w to c-6 with NP205

Post by Mesozoic »

I'm cranking 350 hp and 450 ft-lbs of torque from my basically stock 400M after replacing the timing chain and cam, if that helps. I also fuel injected it, so I'm sure that helps with torque production. I wouldn't replace the 400M with a 351W unless you were able to dish out for a stroker kit. Dyno graph says my '79 was making 400 ft-lbs of torque at 1500 RPM.
User avatar
Andy Jones
Posts: 2205
Joined: Tue Dec 08, 2009 2:47 pm
Bronco Info: In the Works!
Location: Canyon Lake,ca
Contact:

351w to c-6 with NP205

Post by Andy Jones »

I have a C6 with np205 for sale, if interested. $200 or best offer.. I'm not gonna use it, just want it out of the garage .
User avatar
Mesozoic
Posts: 36
Joined: Fri Feb 20, 2015 9:18 pm
Bronco Info: '79 Bronco: 408C-ZF5-NP205 SEFI-EDIS8; 4" lift, Dana 44/Ford 9" w/4.10s, locked
Location: Tucson, AZ

Re: 351w to c-6 with NP205

Post by Mesozoic »

I was thinking a bit more about this and I realized that a 351W will mate nicely to a 4R70W out of a '99-01 4WD Explorer. The NP205 bolts right up to the 4R70W. This would give someone the option of a) fuel injecting their engine, b) doing away with the distributor and replacing it with EDIS, and c) having an overdrive transmission that works with the stock transfer case. The 4R70W is a very strong transmission... I'm cranking over 500 ft-lbs of violent power through it in one of my Mustangs.
wyoming4x4
Posts: 51
Joined: Sun Jun 19, 2011 8:13 pm
Bronco Info: 1977 ford 4wd mountain truck, 1970 ford crewcab 4wd being built. autofab parts also.
Location: wyoming

Re: 351w to c-6 with NP205

Post by wyoming4x4 »

400 ford 434 stroker! 600 horse not hard to do!
User avatar
Mesozoic
Posts: 36
Joined: Fri Feb 20, 2015 9:18 pm
Bronco Info: '79 Bronco: 408C-ZF5-NP205 SEFI-EDIS8; 4" lift, Dana 44/Ford 9" w/4.10s, locked
Location: Tucson, AZ

Re: 351w to c-6 with NP205

Post by Mesozoic »

Yeah, I'm a big fan of the Ford 400, myself as well. I especially like the dry manifold. However, if you had to do a small block Ford, the 4R70W is a good option in 4x4 form. Apparently, someone is making adapters to mount small block Ford transmissions to big block Fords now: http://www.transmissionadapters.com/for ... nstall.htm
User avatar
Wrightracing.net
Posts: 2199
Joined: Thu Oct 28, 2010 9:58 pm
Bronco Info: 1972 Bronco with an 86 chassis, full cage and Long travel coil-over suspension.
Location: San Diego
Contact:

Post by Wrightracing.net »

The issue I would be worried about would not be the horse power but the Bronco is a heavier vehicle and puts more wear and tear on the transmission. Just like the AOD, the 4R70W is made for a light duty application. If you want a overdrive then a E4OD with upgrades would probably be a wiser choice. That being said, I have ditched my AOD for the C6. Now the 400 makes more Hp and Tq right out the box unless you go with a stroker 351w. One other thing to consider is that the 400 is heavier than the 351w. It depends on your budget. You get more bang for your buck by up grading the 400.
User avatar
Mesozoic
Posts: 36
Joined: Fri Feb 20, 2015 9:18 pm
Bronco Info: '79 Bronco: 408C-ZF5-NP205 SEFI-EDIS8; 4" lift, Dana 44/Ford 9" w/4.10s, locked
Location: Tucson, AZ

Re: 351w to c-6 with NP205

Post by Mesozoic »

The other thing is that it's pretty hard to beat the cylinder head design of the 400 since it's essentially a Cleveland engine with canted valves. The dry manifold is another plus in the durability department.
User avatar
birdco85
Posts: 837
Joined: Sat Sep 21, 2013 2:35 am
Bronco Info: 95 5.8 MAF E4OD

351w to c-6 with NP205

Post by birdco85 »

That 400 sounds pretty nice. Wouldn't mind finding one
User avatar
S00TLYFE
Posts: 1065
Joined: Mon Mar 02, 2015 10:14 am
Bronco Info: None Anymore!
Location: Buena Park

Re: 351w to c-6 with NP205

Post by S00TLYFE »

Not sure if it helps but there is a motor and trans for sale right now that would work
https://donttellmywiferacing.bigcartel.com/ (We have shirts, stickers, saginaw pumps, and other Bronco/OBS goodies)
damon1272
Posts: 700
Joined: Tue Dec 15, 2009 8:35 pm

Re: 351w to c-6 with NP205

Post by damon1272 »

One down fall of the 400 is the oiling system, make the needed changes and then you have a solid engine. They make good power but are heavy for what they are.
User avatar
AussieRod
Posts: 2804
Joined: Sun Sep 05, 2010 1:43 am
Bronco Info: 81 Bronco XLT, 250 alloy head crossflow 6, NP435/NP208, 4:10 gears, 31-10.5R15 M/Ts.
Location: Downunder

Re: 351w to c-6 with NP205

Post by AussieRod »

damon1272 wrote:One down fall of the 400 is the oiling system, make the needed changes and then you have a solid engine. They make good power but are heavy for what they are.
That's a downfall I've never heard of. My brother and I ran one in a Mid 70's Falcon at the local drag strip here in Aus for 2 years, bone stock bottom end changing at 5800 rpm and NEVER had any oiling issues, even with the STOCK front sump oil pan. However, I would invest in a 7 - 8 quart oil pan as a MINIMUM. The stock pump can empty the standard oil pan at 3800 - 4000 rpm. Any adverse angles with a mildly low oil level WILL kill the engine. Just my $0.02.
damon1272
Posts: 700
Joined: Tue Dec 15, 2009 8:35 pm

Re: 351w to c-6 with NP205

Post by damon1272 »

Old Ford Motorsport catalogs used to have engine building tips. The text below is from an add but it outlines one of the problems with the 400M. I remember reading about this mod after toasting the engine in my Dad's truck. Cheap fix. Another way to address it is to bush the lifter bores.

One of the tricks is this oiling system modification kit. It is one of the cheapest, easiest mods that you can do to your 351 C, 351 M or 400 to help it live longer, especially at higher engine speeds. Clevelands do not have the best oiling system, but it can be helped. The problem is that Clevelands oil the camshaft bearings first, and then the main bearings. The result of this is oil starved # 4 and 5 main and rod journals. My kit routes oil directly from the front of the block near the oil pump to the back of the block to force feed the # 4 and 5 main and rod journals and adequately oil them. It is a completely bolt on kit that you can install at home with simple hand tools. It will not hurt your engine, it will only help it.It installs in less than an hour.
User avatar
ChaseTruck754
Spy/Ninja
Posts: 9194
Joined: Thu Jan 28, 2010 9:46 am
Bronco Info: Don't have one - just old Ford trucks
Location: Huntington Beach, CA

Re: 351w to c-6 with NP205

Post by ChaseTruck754 »

While I have no personal experience with oiling issues in the C series I have read about it a decent amount on the old ford truck forums. Seems to be very well known & semi common. And as pointed out above there is no lack in info or kits to combat/fix it.
Owner of only dead and forgotten projects
User avatar
AussieRod
Posts: 2804
Joined: Sun Sep 05, 2010 1:43 am
Bronco Info: 81 Bronco XLT, 250 alloy head crossflow 6, NP435/NP208, 4:10 gears, 31-10.5R15 M/Ts.
Location: Downunder

Re: 351w to c-6 with NP205

Post by AussieRod »

Again, not to disparage anyone or their knowledge, but tomes and thousands of pages have been written by "experts" about the Cleveland engine's mythical oil :problems". My opinion is based on real world experience with these engines. A PHYSICAL limitation on the 400"M" is that the large 3 inch main bearings will only withstand approx. 6000 rpm safely, or the surface speed between the crank surface and bearing will start to strip the bearing material out. With modern materials and oils, this no longer occurs until closer to 7000 rpm. The "C" engine's biggest achillies heel is the fact that it holds an ENORMOUS amount of oil up in the valve covers at any time during hard use (3000 rpm+). The drain-back passages are very small for the job and are hard pressed returning the oil fast enough. One of the local tricks was to drill the rear of the cylinder heads and install drain pipes directly back to the rear of the oil pan, increasing the oil flow OUT of the head. This did wonders to help, but the small amount of oil the stock pan contains is NOT ENOUGH for hi-perf use. It has been proven that under hard use, if the oil level falls below the "full" mark, the standard oil pump can literally EMPTY the stock oil pan at approx. 4000 rpm, which results in oil starvation and a destroyed engine. A large capacity oil pan is a MUST on the "C" engines regardless of whether it is a stocker or HP version. I've built several 351C racing engines, both for myself and others. Mick and I ran one for 4 years, regularly running thru the traps at 7600 - 7800 rpm, with just a Melling HV oil pump, Milodon drive and 7 litre oil pan with NO failures. When the engine was torn down for sale inspection, the bearings looked brand new. My last effort ran at the 2017 Adelaide Clipsal 500 in a support race recently and was hitting 8200 rpm at the end of the long straight. Stock crank (internaly balanced), Eagle rods and Mahle pistons topped by CHI heads, intake and 800 cfm Holley with full Isky roller valvetrain including stud girdle(s). Melling HV oil pump, Milodon driveshaft and custom made 8 litre oil pan. No restrictors or fancy mods except for external drainbacks on the rear of the valve covers back to the pan. A simple, strong combo that has run without issue for 3 seasons, regularly getting top results. That said, the oil hose trick from the front to the oil light switch port is always a good inexpensive way to ensure EVEN oiling front to rear. Just sayin".
User avatar
Mesozoic
Posts: 36
Joined: Fri Feb 20, 2015 9:18 pm
Bronco Info: '79 Bronco: 408C-ZF5-NP205 SEFI-EDIS8; 4" lift, Dana 44/Ford 9" w/4.10s, locked
Location: Tucson, AZ

Re: 351w to c-6 with NP205

Post by Mesozoic »

Totally agree with the above post. I have a '79 Bronco with a 400 that I rebuilt back in 2000. It has about 100,000 miles on the rebuild now and runs great. It does get low on oil pressure if the engine is run at 3000 RPM sustained, probably for the indicated reasons: valve covers full of oil and not enough drain back at that engine speed. It is a very torquey engine and with SEFI installed on top of it, it's such a cheap engine that I'm generating 400 hp and over 450 ft-lbs of torque out of stock heads, 8.5:1 compression, long tube headers, and a mild flat tappet cam. There are a few years that exhibited some kind of casting flaw, but as long as you've got a post 1978 block you're good. Another bonus is that the Ford 400 was produced mainly with the big block Ford bellhousing pattern, but there were also a few small block Ford bellhousing units floating around too... might be a bit tough to find these days.
'79 Bronco: SEFI-EDIS8 8.5:1 400M-C6-NP205-Ford9-Dana44-4.11s locked, 35s, lifted 4"
Post Reply