Stroking a 1989 Ford 5.0Ltr V8

[sandpitcobra]

Can anyone give me advice on turning this engine into a 347 or similar? If I buy new rotating assembly is that all that is required and where do recommend buying it from. Do I need to do anything with the EEC?

Thanks

[blykins]

I can provide a Scat complete rotating assembly including a Scat crankshaft, forged I-beam Scat rods, pistons, bearings, and rings.

You would need to have the assembly balanced, the block machined and the short block assembled if you're not familiar with engine work.

You would also need a larger camshaft to help out with the extra displacement.

On a 3.4" stroke crankshaft, the bottoms of the cylinders need to be clearanced so that the rod bolts won't hit.

This would be a nice step up from a 302....347's make good power.

[sandpitcobra]

Hi Brent,

Can you give me a price. The scat kits on summit racing make no mention of changing the camshaft? Is this a must? Will the EEC still function correctly?

Thanks

[blykins]

A camshaft swap is not necessary. However, I would recommend it. Anytime you add displacement with the intention of keeping the same powerband and heads, duration needs to be increased.

If you're still using the stock 5.0 top end (heads, intake, cam, etc.), then you probably won't see much of a difference in horsepower with a 347, but the torque will go up.

The computer will still function correctly. The worst case scenario is that you will need to have a tune so that the computer can know how to handle the added displacement in the most optimum manner.

I would recommend finding an engine builder in your area so that you can discuss the machine work/assembly with him. If he's doing all the work, he can probably cut you a better deal on the stroker kit than I can.

[sandpitcobra]

Hi Brent,
Here's the problem. I am in the dark a bit because I live in Dubai, UAE and none of the machine shops here know how to do this. They will rebore the block, fit and balance everthing but the rest I will have to show them.
The reason I am contemplating the 347 is because my crank needs re-grinding and the pistons need replacing so I figured I might as well up the BHP. Everthing on the engine is stock so far.

[Gunner]

I believe that the only special steps for a 347 stroker are that some relief notches have to be cut in the pan skirt. Mine has little half-moons in a few places to clear the rod bolts. Everything else is (or should be) standard balancing, boring, fitting etc. that any competent engine machinist should be able to do.

As blykins has partly said, though, punching the engine out to 347 cubes with no other changes won't gain you very much. You need better-breathing heads (and intake, and often exhaust) and a cam optimized for the new overall setup, to get noticeable improvements from the work.

If you're doing the 347 conversion as an upgrade to a regular rebuild, that's a good start, because the bottom end of an engine is the hardest part to upgrade. But you should consider some better heads as your next step, to get more out of your investment.

If you're going to be running the engine very hard, or at higher RPMs a lot, you might consider a bearing girdle as well. This will stiffen the block structure and contribute greatly to engine longevity with the long, thrashing throw of the 347 crank. Girdles are pretty much a bolt-on deal if they come with the longer cap studs or bolts. Some relief work might need to be done if the girdle doesn't clear the larger crank, but most I've seen are set up for stroker motors already.

[blykins]

I agree with you there.

If you do a stock rebuild, you're already out a set of pistons, rings, bearings, having to have the crank reground if necessary, and the rods resized. For the amount of money that you'll spend, it won't cost much more to just buy a stroker kit.

Just for giggles, I threw a stock 5.0L engine into my Engine Analyzer software.

Horsepower was 230hp @ 4500.
Torque was 302 lb-ft @ 3500.

With a .030" overbore and a 3.4" crankshaft, we get:

Horsepower 241hp @ 4000.
Torque 346 @ 3000.

If you plan to do some modifications later on, this would be a good stepping stone. However, if you never plan to change the heads/cam, then I'd probably just go back with a stock rebuild.

A cam swap would be very easy at this point. If you look at the figures I showed, you can see my point about a larger displacement with the same camshaft. Peak hp rpms go down (at this point it would almost be a dump truck engine peaking at 4000 rpm) and peak torque rpms go down.

If you just went with an upgraded hydraulic roller (still very streetable and would be extremely easy to change when you have the engine apart) you would at least gain a few more horsepower and you would have a nice baseline for a head swap later on.

As far as stroker kits go, the only difference in preparation/assembly is that you will have to clearance the bottoms of the cylinders. This is very easy to see with just a mockup of the crank, rods, and pistons. What I'm saying is that if they can do machine work and assembly, then there isn't anything different about a stroker setup.

If you went with a 331 instead of a 347, then you could probably get away with no cylinder clearancing.

[sandpitcobra]

Thanks for the replies. I must admit I thought I would get more HP by changing the crank but it does give me great potential for futher mods.

[blykins]

Ian, I responded to your email.

[Jerry Clayton]

Sandpit

The eec will need to have a chip burnt and installed--it cannot do the correct adjustments for the engine if it doesn't have the correct size engine/fuel injectors available.
If machine work is a problem over there , you might think about a Dart SHP block with a 4.125 bore you will get 363 inches---We sell 363s machined, balanced,assembled with Dart SHP block, either Scat or Eagle forged crand rods Mahle or SRP pistons--if interested please PM.

Jerry