Thinking about stroking my 4.6L. It's a '97 with 150k. I was wondering if anybody out there has already done this project and could let me in on the pros/cons?

 

More CI, longer stroke = more torque. You can get it up to around 5.0L. Check with DSS racing for nice kits.

 

Go 5.4L to start with or are you sticking with that block for all the 4.6L goodies out there?

 

You can go as far as 324 CID a sleeved block (they can do iron blocks). Really it's going to depend on what you want from the engine. If it's just more cubes for torque and not planning on a high power build then just swap in a 5.4L. If you want a bit more power to play with then I'd suggest going to a supercharger or single turbo setup.

 

You ever price sleeving? I got a quote from Darton to increase my bore to 3.70. quote:Hello Ron,
If you have a truck block then it is cast iron. If you do get a aluminum 5.4L block we do make a MID sleeve for that block also that can go to 95mm bore. The sleeves are custom made to order and cost $1200.00 for all 8 sleeves, o-rings, lubricant and Loctite. Installation for the aluminum block is $1375.00 for a new block and $1175.00 for a used block. The new blocks are more for labor because we need to Metalax or stress relieve the block. Custom sleeves take about 6-7 weeks right now and about a week for installation.

Let me know if you have any more questions.

 

Gee, a guy down in the six forums said $50 a hole....

 

Yeah I got sticker shock to. Think I'll stick with stock aluminum block unless I can find a stroker.

 

I didn't say it was cheap. I said it was an option.

 

Then you have the shocking reality.

 

I recently built a stroker DOHC for one of my cars. I was running a relatively stock 4.6L DOHC with a Kenne Bell 2.1L SC on top when it spun a rod bearing. The block only had 3,401 miles on it at the time, so the bores were still in great condition (though I did have them honed of course). I went with a complete forged stroker rotating assembly from Livernois, which was only $100 more than a forged stock stroke rotating assembly. Dyno sheets from the "before" and "after" showed another 34 rwhp and 56 rwtq at the same boost level. While I attribute most of the hp gain to other work that I did elsewhere on the engine, mainly headwork and cams, most of that torque increase was likely produced by the additional stroke.

However, with the tiny bores that these engines have, stock SOHC, and even stock DOHC heads have a hard time filling the additional displacement when you run a stroker crank naturally aspirated. I went the stroker route because I needed a new rotating assembly, the stroker assembly was only $100 more than the stock stroke version, and I knew that I wouldn't have any problems filling the cylinders with the twin-screw SC on top. It's up to you, but if you're rotating assembly is in good condition, I don't know that I'd spend the $$ on a stroker assembly.

-Rod

 

What would you say to boring/stroking a 5.4 and S/C it?

 

Honestly, I wouldn't consider stroking a 5.4L, as it's already plagued by the long stroke in relation to the small bore diameter as it is.

Throwing a little boost toward it certainly wouldn't be a bad idea though.

-Rod

 

Yeah but there's sleeving yo help and long stroke makes torque. There's a dyno software program available that would probably give some answers.

 

White max..
sounds like you have rebuilt the 4.6 dohc.
Is there any do's and don't's to consider when working on these engines?
You know, things that one might over look ordinarly.

 

It's mostly just like rebuilding your average smallblock, but there are a number of exceptions to that. First off, cam timing is a bit of a pain with the DOHC. It isn't all that difficult, you just really have to pay attention to detail, and give yourself plenty of time to do it. Secondly, priming the engine with oil before firing for the first time is nothing like your usual OHV engine, where you would be able to spin the oil pump via a drill. Ford makes a special oil priming setup that looks remarkably like mine.



The "cooling mod" that you'll hear about on a number of websites is a good idea. Basically, with the stock coolant system, hot coolant is able to exit the rear of the passenger side head (it flows to the heater core), however hot coolant has no path out of the rear of the driverside head. Due to this, cylinders #7 and #8 are most prone to detonation, and are typically the cylinders that you'll see most problems with. The cooling mod replaces a freeze plug at the rear of the driverside head with a nipple, allowing you to tie it into the outlet from the passenger side head.

I could keep going and going about these engines, but I'm afraid I'm taking this thread off topic. It's a really long thread, but if you'd like to see what I did with my 4.6L DOHC, take a look at this thread: http://forums.tccoa.com/showthread.php?t=97219. My screenname over there is "racecougar", and that thread goes through installing the SC, spinning a rod bearing, and the buildup of the new stroker engine. For the mod list and some pictures, my gallery for that car is here: http://forums.tccoa.com/vbpicgallery.php?do=view&g=52.

-Rod