Hey fellas,

So I want to start planning out my 351W build for my 1978 F150, but I need a hand starting my selection of blocks.

My build is going to be a weekend warrior, potentially a daily driver if it's reliable enough. So reliability is key here.

I would like to make between 350-500 hp, but not break the bank in doing so (so I'm guessing this is a top-end build).

The biggest question I have, is:

What block should I start with for planning my engine build??

The way I see it, I have 4 potential blocks to use... 2 are already in my possession (#1 and #2).

1) 1972 351W (thick webbing from what I've read) from a Galaxy. Currently has low compression in 1 cylinder but I haven't pulled it apart to see what the problem is.

2) 1979 351W (engine was seized and heavily rusted in the cylinder walls - will need a 0.060 bore at least)

3) A roller block - F4TE from a 94-97

4) A Sportsman Block from

I'm having issues selecting the proper block to use because:

1) The F4TE blocks apparently have some issues...

Must Read....PSA for Windsor Roller block guys - Ford Mustang Forums : Corral.net Mustang Forum

2) The 79 and 72 blocks would both require some $$$ modifications

a) OEM Sypder + Dogbones + roller lifters + small base-circle cam (poor selection of cams!) + machining costs
b) Link-bar lifters + small-base circle cam (not sure that I like having a very small selection for my cam...)

3) The sportsman block is bloody expensive!

Because my build is for reliability, I'm not sure that I want to go the route of a flat-tappet cam (but I could be wrong). The entire cam break-in period and all the labour associated with it seems like a bit of a nightmare if you ask me.

This leaves me with doing a hydraulic roller set-up, but as I've already described... The F4TE blocks have issues, and the older style blocks require a lot of extra $$$ to turn them into a roller block (and cam selection is an issue as an end result).

Anyone want to start pointing me in the right direction for my build? I could use some advice.

Probably a few things need clarification:

1) Are small-base circle cams really that bad (selection, reliability)?
2) Is the break-in period for a flat-tappet motor really that bad?
3) Will I still get the same reliability out of a flat-tappet cam'd 351 as opposed to a hydraulic roller set-up?

 

Just using my personal opinions here. I have no interest in running any small-base circle cams. I've always preferred the wider selection and lower prices of flat tappet cams. People have been installing and breaking in flat tappet cams successfully since long before you and I were born. It's not that big of a deal. Just with the formulation of modern oils we have take more specific care with the lubrication used during cam break-in.
That said, when I have and use an F4TE block I think it silly not to run a roller cam in it. Even though that's exactly what Ford did with the first generation Lightnings.
As far as reliability, I expect either type of camshaft to well outlive how long I won the vehicle. I've seen flattened lobes, seized, and even snapped in two camshafts. I consider all those issues to be pretty darn rare.
I've had a '69 and a '78 block flipped over in my shop. Side by side like that you can see the extra ten pounds or so of extra metal the earlier blocks had. What I've never seen is any actual proof that that extra stuff makes any useful difference in strength. Ford apparently figured the engines could live without it and that's all we know for sure.
If it were me, I'd build the '72, with a flat tappet. Probably the '78 is a wash. If you think it'll take .060, it's probably worse than that which is kind of hard to tell until you start machining. The only way to save one like that is to sleeve it and that's not worth doing really. I don't know it isn't savable, I just don't want you to waste your time and money on one like I did once.
If you are determine you need or want a roller cam, I'd hunt a roller cam engine. My last one I scored at a pick-n-pull to rebuild for $150. It looked a lot better than I expected when I got it home. I ended up cleaning it up with some gaskets and putting it in my F150 pretty much as-is. Where I have been beating on it without mercy for the last two years. It doesn't seem to mind. (I also have a '67 Mustang I put 1978 351W in. On deck is a thrashed '69 351W which happens to be just the thing for the pile of alleged '69 Mustang I scored a while back. Sold my 3.8 F100 which had a police car 351W and AOD swapped into it. I LIKE 351W's.)

 

Yeah heard about that but I'd still look for a roller block to use, even if you had to buy 2 or 3 to get one without cracks you'd still be further ahead. There has got to be millions of these motors out there now so even though one shop is seeing some with cracks it's still an insignificant percentage in the big scheme of things.

 

I'm tempted to build a flat-tappet motor. The break-in process kind of frightens me... I'm not a big fan of having to disassemble and then reassemble things once I've already put that much work into it to get it built in the first place.

In addition, the constant worrying of the zinc-additives and the occasional valve lash adjustments seem annoying at the best of times.

If you're going to go through 2-3 blocks just to find a decent one (that will withstand 350-500 hp without the cracks busting wide open), wouldn't it just be better to buy a Sportsman block for $2500?

At roughly $700 per F4TE block, that's a potential $2100 I'd be spending just to start my build.

Got any advice on buying a F4TE block???

Used? eBay? Our junk yards get picked over VERY quickly up North, so finding one might be tricky + a lot of effort (no power tools allowed at the pick-n-pull).

EDIT: And what's a decent price for a F4TE block now-a-days? I see anywhere from $700 - $1000.

 

Get on Kijiji and look for a used block or motor in or near a major city, prices should be a lot better... like more in the $100-$300 range.

 

Is that for the block only? Or the entire motor (intake to pan)?

A guy near Saskatoon is asking $800 for a running 351W with 120K. He wants the buyer to take the whole motor and pull it themselves for $800 (which to me is a rip-off.. but what do I know lol).

 

Just find a 1984 and newer block to get a one piece rear main seal. Link bar lifters allow the use of a standard roller camshaft in any block. Reduced base circle cams are only needed if your trying to use the stock dogbone roller lifters in a non roller block.

 

Thanks for this reminder dueller. I re-read through a few articles and I think I've got my head on straight now.

link-bar roller lifters + standard cam in an old block works, but it's expensive.

spyder + dogbones + small-base-circle cams in an old block works, it's less expensive than the link-bar set-up, but requires the 2-3 holes to be tapped in the block.

From this article (Yes - they're talking about Chevy, but the same principles apply):

Converting a Hydraulic-Roller Camshaft - Tech Article - Chevy High Performance Magazine

I should also be considering the extra costs of (with an old block conversion):

1) custom length pushrods
2) dual-spring + wider valve springs
3) Roller-cam button (not allow the cam to move)
4) Cam thrust bearing cannot deflect the timing cover - solution:
----->a) Two-piece timing cover
----->b) Water pump with studs to contact the timing cover to prevent deflection
5) After-market fuel pump push-rod if I'm using a mechanical fuel pump
6) Custom camshaft thrust plate
7) Pay attention to distributor gear composition (so that it matches the camshaft gear)

That's a lot of extra costs to convert an old block!!!

 

None of that stuff applies to Ford. Chev did a bunch of weird stuff when they changed over.

Custom length pushrods are a given anytime you change camshafts, deck the block/heads or use different thickness head gaskets. The price of the pushrods are the same no matter what length you need.

New valve springs are also again a given if you change to a performance camshaft for it to work to its best potential.

Timing chain set. You can use what ever style you want with either camshaft type. Some may not be able to retain the fuel pump eccentric though. 2 piece fuel pump eccentric requires the long camshaft dowel and the one piece requires the short camshaft dowel. You only need to play with camshaft retainer plate if you don't have enough endplay clearance or using a torrington bearing timing chain set as those require countersunk bolts.

Distributor gear is pretty simple. Flat tappet = cast gear and roller cam = steel gear. Sadi and billet cores both use the steel gear.

 

Well that's all fantastic news. I'm not sure what any of that stuff costs in the first place, but not having to deal with it will be nice! Big thumbs up for

I always assume the word "custom" adds $$$ (ie custom length pushrods).

So now it looks like I've narrowed down my search to 2 blocks:

1) An F4TE block ("you'll be ahead by using this block" - when people say that, they're referring to the cost of converting an older block, correct? Or is there something else I'm missing?)
2) A pre-94 block, retrofit to a roller block

Now another question... Why is the 1-piece rear main seal such a big deal?

Certain engine builders specifically want a 1969 351W block for a higher HP build... yet it's got a 2-piece rear main seal. So what's the big trade-off that they're making? Can the 1969-1983 blocks retrofit a 1-piece rear main seal? Looks like older blocks can indeed be machined to have a 1 piece rear main seal (just adds to the cost of the conversion...).

 

They say to use the F4TE block as its just cheaper for a roller camshaft. A word of note is the factory lifters do have a maximum camshaft lobe lift. It's not something you probably need to worry about unless you plan on running a big racing camshaft. Linkbar rollers do not have this limitation.

1969-1974 blocks also have a shorter deck height than the 1975-97 blocks. Have to watch piston compression height and intake fitment.

The one piece seal is just nicer to use and much easier to install. There is a reason every manufacturer has been using it for the past 30 years. You can put the seal on with your fingers when you put the crank in the block. Slide the seal on, torque the rear main cap down and its done.

Two piece seals have to be offset in the block. There are rubber and rope styles. Rope ones have to be soaked in oil and both styles have to be sitting square before torquing the rear main cap. Aftermarket cranks also won't have the knurling needed to maximize the seal life.

It's not worth machining the block for a one piece seal and you won't find anyone in Saskatoon that will even do it. If its not machined 100% concentric it will never seal and the block is scrap.

 

Sounds like I'm really narrowing my search down here haha.

After much searching last night, it appears that the two-piece rear main seal can be a enormous pain in the rear if it gets installed incorrectly (which I'll probably do...).... or like you said, if an after-market crank isn't quite the same as the stock crank.

So 84-97 is what I'm looking for I guess. That's a much smaller range and at least gives me the ability to sell off some of the stuff I currently have.

Just as an aside... What the heck would a previously seized 1979 351W be worth? I may as well sell off what's worth $$$ to fund my engine build. I've got everything, from carb to pan... but the block would need to be bored 0.060" to make it usable. It's got some fairly deep pits from rusting/seizing.

As another aside, what's a 1972 (thick-webbed) 351W worth? Also have everything... carb to pan, but cylinder 7 has low compression... and it has some newly broken (by me) water pump bolts (stoopid aluminium timing covers!).

 

As far as block worth probably not much. Several years ago I watched 4 70's 351w blocks go for scrap but they were all already .040 over.

Just a quick search on summit for stroker kits:
0.030 - 74 results
0.040 - 10 results
0.060 - 4 results

Piston selection gets very small once you go over 0.030 bore.

I built a 302 stroker because I wanted to build a "302 that could" and you can get stock bore roller blocks for $100 all day.

 

[QUOTE=51dueller;15702421]As far as block worth probably not much. Several years ago I watched 4 70's 351w blocks go for scrap but they were all already .040 over.

Just a quick search on summit for stroker kits:
0.030 - 74 results
0.040 - 10 results
0.060 - 4 results

Piston selection gets very small once you go over 0.030 bore. [QUOTE]

Well, that's a dead end, but no worries. I may as well post some stuff up on kijiji and see if I get any bites. If not, I can always collect the scrap value!

$100??? Where do you find that deal!?

Some guy in Saskatoon wants $800 for a 1997 351W (intake to pan, but I have to pull it myself). It's "supposedly" only got 120K on the engine, but that's a tough number to believe....

 

Bucks auto parts sells engine short blocks for $100. You unbolt it and they will lift it out with the payloader then drop it in your truck.

Although not quite as common anymore but there is usually some LTD/Grand Marquis and F-150's out there. I've seen 351w's but they are usually in the Econolines though.