O.K. maybey not 20 Questions, but a few...

1) What is the purpose of balancing the motor?? I'm doing a rebuild on a 400, and I'm using the original crank and rods. The only diference are the flat top pistons... Is it worth balancing??

2) Is a 600CFM edelbrock w/ electric choke big enough??

3) Can I use the stock distributer gear with my Comp Cams Magnum 270H Cam???

4) Will a MSD 6AL be worth the money i.e) better milage, power, etc.

Well, that's about it.... When I think of others, I'll post them too...


Thanks
Skud

 

> 1) What is the purpose
>of balancing the motor?? I'm
>doing a rebuild on a
>400, and I'm using the
>original crank and rods. The
>only diference are the flat
>top pistons... Is it worth
>balancing??

Balancing a motor is always a good idea if you plan to keep it for awhile. It helps in extending the longevity by cutting down on destructive vibrations. The only time I wouldn't bother to balance the bottom end is if I was only replacing the rings.

> 2) Is a 600CFM edelbrock
>w/ electric choke big enough??

Should be fine if you keep it 5500 or below.

> 3) Can I use the
>stock distributer gear with my
>Comp Cams Magnum 270H Cam???

What does Comp Cams say?

> 4) Will a MSD 6AL
>be worth the money i.e)
>better milage, power, etc.

If you build it right and your Duraspark is working fine I'd stick with it. When it goes bad then replace it with an MSD or Crane or Jacobs or whatever.

 

Thanks for the reply bill... I finally remembered my other question.

While I was taking off one of the rockers arms, I broke one of the oil deflectors. My question is: Are they important??

Also, what is the redline for a 400?? I've heard from 4 to 6.

Thanks
Skud

 

>> 4) Will a MSD 6AL
>>be worth the money i.e)
>>better milage, power, etc.
>
>If you build it right and
>your Duraspark is working fine
>I'd stick with it. When
>it goes bad then replace
>it with an MSD or
>Crane or Jacobs or whatever.
>

skud,

You might get an improvement in mileage or power from an aftermarket unit, but it is not a sure thing. The only real downside to the DuraSpark II system is its performance at over 7K rpm. The only reason you'd "need" an aftermarket system is if you plan routine jaunts into that 7K+ rpm range.

I've heard bad things about all the aftermarket ignitions, but less bad things about MSD than the others.

The main downside of the aftermarket units is reliability and ease of replacement/servicing. DuraSpark is pretty easy to replace (you can get them almost anywhere) and cheap enough to comfortably carry a spare for backup. At $150-350 (or more) for each unit, spare aftermarket ignition modules are not as easy to afford.

Of course, if you never drive farther than walking distance to a well-stocked performance parts store, or you're willing to have your truck down for 2 weeks everytime the ignition module dies and you have to send it back to the factory for warranty replacement, then you don't need to keep a spare aftermarket ignition module on hand.

You might be able to get by with an aftermarket ignition system that can be switched over to a DuraSpark system for a backup.

To me, the less-than-OEM reliability and high expense of carrying spare parts makes the nebulous performance improvements a dubious investment.

BubbaF250

1980 F250 4x4 Custom, 351M/NP435/NP208/D44HD-TTB/D60-FF/3.55s 6750 GVW, Rust & White.

 

> While
>I was taking off one
>of the rockers arms, I
>broke one of the oil
>deflectors. My question is: Are
>they important??

skud,

That deflector gets oil to lubricate the rocker fulcrum, so yes, it is important. Maybe now would be a good time to consider upgrading to roller rockers?

> Also,
>what is the redline for
>a 400?? I've heard from
>4 to 6.

I have never seen a published "redline" for M-block engines, probably because in factory trim (wimpy cams and 300 cfm 2V carbs) they run out of breath long before they get close to hurting themselves.

The practical redline for your engine depends mostly on how you build it. Balancing will buy you another 1-2K rpm. The Comp 270H cam is rated for up to 5.8K rpm, and if your engine is balanced, it should have no trouble at that speed. If you want to maintain that kind of speed (or more) for any length of time, you should think about minor oiling system modifications as well.

BTW: frankly, I think the intake duration @ 0.050" on the 270H is excessive, though I like the 224-degrees exhaust duration and 0.519" lift. I'm afraid that 224-degrees intake duration will hurt your bottom-end power, without enough improvement at higher rpm to justify the loss.

I would recommend a dual-pattern cam with intake duration about 215 degrees or so @ 0.050" lift, and the same 224 degrees exhaust duration and similar total lift. I think the Crower cam that Bill chose for his 400 has better numbers than the Comp 270H.

BubbaF250

 

> While
>I was taking off one
>of the rockers arms, I
>broke one of the oil
>deflectors. My question is: Are
>they important??

Yes they are important. The oil deflectors as the name implies, deflect the oil down so it lubricates the rocker pivot area. You need to get another one and install it.

> Also,
>what is the redline for
>a 400?? I've heard from
>4 to 6.

With a stock 2V they run out of breath around 4K. If you add a bigger cam & 4V with some headers you should be able to get 5500 no problem. If you do some port & clean up work on the heads and have a big carb and single plane manifold then 6K-7K is reachable but you'd better have done a pretty stout rebuild.

 

>That deflector gets oil to lubricate
>the rocker fulcrum, so yes,
>it is important. Maybe now
>would be a good time
>to consider upgrading to roller
>rockers?

FYI...if you upgrade to rollers then you'll have to switch to 7/16" studs instead of 5/16" bolts, so you'll need either to spend some $$ at the machinists having the pedestals milled & re-tapped OR buy the conversion kit Crane makes. Either way you need to factor that in to your cost if you decide to go with rollers.

 

Actually, you can buy full roller rockers from Ford Motorsports that are a direct bolt in on stock heads. No machining or bigger threads required. They're priced at $300 from P.A.W.

Stryder

 

What kind of oiling mods should I be doing??

Thanks
Skud

 

> What kind
>of oiling mods should I
>be doing??
>

I limited mine to adding a line from the oil passage by the fuel pump to the O.P. sending unit port. I used a 90 and a 45 AN-6 fitting(s) and a brass T with 4 feet of high quality line. You'll also need a couple of NPT to AN adapters. I also added a HV pump and a ARP driveshaft.

 

Food for thought.... what is your intent of your rebuild???? Do you want longevity or more power? If it is pure longevity stick to a stock rebuild, do not create a hybred engine, stick to the basics - they do work fine. If it is bottom line power there is no substitute for cubic inches. Consider a 460 conversion. A 460 can be built up cheaper and result in more reliable power than the 400. The 351M/400 is a great engine IF it is used for what it was designed for. It is a working engine that provides adaquate horsepower based on its design. Speed cost money... how fast you want to go?

 

Thanks for the input, Bob, but I think I will stay with the 400. I don't want to have to screw around with the mounts and the like. I want a truck that will have lots of get-up-and-go. I don't want a Windsor or an FE or a 429/460 mainly for the fact that i want to keep the original engine. Besides the 400 is better anyway!!! (just playin')

The rebild kit that i got was from Canadian High Perf. It included Clevite 77 main and rod Bearings and a Victor Reinz gasket set. From what I've heard, Clevite 77 is good.

I took the block in to be checked, and there was almost no wear on the block. The motor probably shouldn't have been rebuilt because I just found out it only had 25,000 Miles on it. But it was leaking oil at the front and back, and I wanted to spruce it up a little anyways.

The C-6 was leaking oil like a siv...., so I got a brand new rebuilt w/shift kit for it.

I also picked up a set of rebuilt heads for $350 CAN. Some guy had them rebuilt, 3-angle valve job, new valves and bronze guides. I guess he picked them up, bolted them on and filled the rad with coolant. Then he found he had a crack in the block. So, he brought them back, and told the machine shop to sell them... Now they're mine...

I got a Comp Cams Complete Systems Kit. I would recommend this to everybody who wants a valvetrain upgrade. You tell them what motor you have, and what cam you want... That's it!! They send you correctly matched valve springs, lifters, retainers, cam, timing set, stickers, and instructions... Man, I sound like a salesman... If you order it, make sure they send you the right locks... Mine didn't fit.


I thank you all for your input, and hopefully my 400 rebuild goes good, now all I have to do is get my motor balanced... I have to drive 250 Miles to do it to... Arrgh

Thanks
Skud

 

> Consider a 460 conversion.
> A 460 can be
>built up cheaper and result
>in more reliable power than
>the 400. The 351M/400
>is a great engine IF
>it is used for what
>it was designed for.
>It is a working engine
>that provides adaquate horsepower based
>on its design. Speed
>cost money... how fast you
>want to go?


Man that fries me! Let's not forget that the 460s produced around the same time as the 335 series was being introduced were victims of the smog police also. Why do you think Ford kept opening up the combustion chambers? They went from 75 to 91 then to 96 ccs in order to reduce the C.R. and the horsepower dropped SIGNIFICANTLY as a result. Now why would I want to run out and buy another lo-po smog motor and still have to go through the headaches of a conversion? I really hate it when people just say "Oh dump the M block and stuff in a 460". For around $2000 (which is what most any decent rebuild will cost if you do a lot of the work yourself) you can build a 400 that will walk away from ANY stock 460.