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New motor build

Shaun

Shaun

Member
Now that my 66 stops and turns well its always been the next part of the plan to build a warp speed motor. The old 289 is working pretty well but it just isn't enough (is it ever?). I still do a little street driving so it needs to have a certain amount of low end but I'd like to build a screamer for the track. I don't think I need to buld something for 8,000rpm, I'd like to bolt it together and leave it alone for 5 years. Shifting at 6500rpm is fine. Looking at a 347.

I've been chatting with a local builder who is actually a Ford engine engineer. Not sure if I'll pay him to build it or have a go at it myself. I'm in the parts research/collecting phase and as motors are not really my strong area (yet), I'd like to kick this around with you guys.

Thinking:

450Hp+
347ci built from a roller 302, unless I find a wicked deal on a BOSS or Dart block I'll stick with the regular block although for under $8k the Ford BOSS 450Hp crate looks like a good deal.
Needs to run on pump gas 93 octane.
Not sure whose rotating assembly to use. SCAT or Eagle both make kits. Not sure if I'll need a forged crank...
Already have a set of 58cc 185 AFR heads
Solid Roller cam of some sort, no idea on what specs.
1-3/4" headers
750 carb of some sort
Victor Jr. intake
Cost needs to stay somewhat reasonable. Nice and simple, no powder adders etc.

Any input is appreciated as well as any links or info on this type of motor. I'd like to read as much as I can. Thanks!
 
Getting 450 HP out of a 347 stroker is fairly easy to accomplish but you should really consider how you will use the engine. Since you will be using this as a track car mainly you may want to give some consideration to a 331 over a 347. You get a better (less severe) rod angle compared to a 347. You gain more torque with the longer 347 rod but the same is done with a 331 rod length vs. the stock 302. The more you wind it up and sustain the higher rpm the more a slightly shorter stroke with a better rod angle will serve you. There is only a slight loss in torque between the two.

As long as you are building from scratch, spend the coin and get forged internals. Good, forged rods are a must, in my mind. Do it once and forget about it kinda thing.
 
I told the builder what I use the car for, he didn't think the rod angle was that big of a deal but I have heard arguments for both. Through the twisty sections of most tracks the car seems to spend most of the time between 3500-6000rpm, some tracks for quite a while too, especially in 3rd gear.

The forged crank add about $400 to the stroker kit price so not a deal breaker. I'm one that doesn't really believe in overkill, there is no such thing as 'too strong'.

Here are the prices he's quoting to put it together. Since I can buy most of the stuff at cost, he'll spec it, I'll supply the parts and he'll build it:

  • The block itself (mag'd for cracks, known good) is $150.
  • Shortblock machining and balancing would be roughly $1500 but there are things in there I would do that most others don't quote like machining the block for a 1 piece rear main seal, machining for 1/2" head studs vs 7/16" stock, etc.
  • If the heads are brand new bare castings figure on $275 or so in valve job and set up. I they are used and need more work the price would increase accordingly.
  • To quote all parts, run everything to and from the machine shop assemble and hot test the engine is $650.

No idea if these are good prices, this is the first person I've spoken to. Some of this I'm sure I can do but what I'm really paying for is his knowledge in specifying the parts and putting them together, the test fire and initial engine stand tuning.
 
As long as you say there is no such thing as overkill...

http://www.jegs.com/i/Horsepower-Sales/ ... oreDetails

When SBF blocks break, it usually is down the middle. This goes a long way to preventing that from happening. Does a good job of holding things true. Cheaper than a Dart block, anyway.

As far as prices go most seem reasonable. $1500 for all the short block work looks high but there is a lot going on there. The one piece seal is a very good plan.
 
You might want to think about shaft rockers too. My setup is much more stable since I made the switch....so far.
 
"silverblueBP" said:
$4,500 :shee
At least the shipping is only $14.99!
Click to expand...

Yeah, but....

That's a ~$1600 4-bolt block that will NOT break... And it's 4.125 bore with a 3.10 stroke, which I like a lot better than a 4.030" & 3.25".
When you look at $1500 in machining just to get a weaker block "ready", plus $500 for a girdle, $1600 for a GOOD rotating assembly, $650 to assemble, plus a few 'incidentals", you're already there... With a band-aid block...

And yeah, $14.95 shipping rocks!
 
"BobV" said:
Sounds like you're looking at building an M-6009-331F: http://www.latemodelrestoration.com/ite ... hort-Block

Good block - check
All forged - check
1/2" head bolts - check
1-piece main - check

:shrug
Click to expand...

All good stuff Cloney, thanks. AFR made pretty good power out of a 331 with 165 heads - http://www.airflowresearch.com/ford_dyno.php. I think alot more could be had with a 347 and 185 heads.

I think my 185 heads would like the 347 better though. Does Ford make a 347 BOSS shortblock? I'm not too worried about the 347 rod angle, I see tons of them at the track. Maybe I need to read about folks blowing them up or having severe wear due to increased side loading to convince me.
 
Whatever path you take, I'd recommend Scat over Eagle. While the Eagle isn't necesary bad stuff, the majority of the quality engine builders out there will need to rework the Eagle products more to get them to their satisfaction level. Some engine builders won't even accept Eagle products because of this.
 
"buening" said:
Whatever path you take, I'd recommend Scat over Eagle. While the Eagle isn't necesary bad stuff, the majority of the quality engine builders out there will need to rework the Eagle products more to get them to their satisfaction level. Some engine builders won't even accept Eagle products because of this.
Click to expand...

Yikes, good to know, thanks. I'm still mulling over exactly what to build but I've pretty much made up my mind to use a BOSS block. Looks like Ford used to offer a crate 347 BOSS shortblock but I don't see it now, only the 331. Fordstrokers.com build pretty nice looking stuff, not sure they are used to the rigors of road racing and what may be different in the build over a drag race car but I'm still researching.
 
Give Woodie (ford strokers) a call and see what he thinks. Definitely ask him about a contantly high revving 347 and the piston skirt wear due to the rod angle that Horseplay mentioned. Cruisers or drag cars don't see that kind of RPMs for that long of time, so the rod angle is something to consider IF you are concerned about motor longevity. If you plan on riding her hard and rebuilding in a few years then it should not be an issue.
 
Shaun,

+1 on Fordstrokers.com. Woody machined my 331. It was a DIY kit, so I assembled it.

Woody is very knowledgeable and helped me tremendously when I was configuring my mill.

Best yet, he didn't try to sell me things that I didn't need.

-Shannon
 
"buening" said:
Whatever path you take, I'd recommend Scat over Eagle. While the Eagle isn't necesary bad stuff, the majority of the quality engine builders out there will need to rework the Eagle products more to get them to their satisfaction level. Some engine builders won't even accept Eagle products because of this.
Click to expand...

same with my engine builder. he refused to use eagle parts. he prefers scat. of course i still got dinged with charges to resize the scat h-beam rods. and the scat crank was forever backordered.

one benefit to a forged crank is the ability to go internal balance easier.

for somparisons sake, i totaled up all the costs (parts, machining, assembly) i have in my stroked 351w to make an equivalent build to the mentioned ford 331. I totaled $3541 and that doesn't include the cost of the 69 block i already had (probably could get a block for $200). I also didn't include tax and shipping costs (another %10). Mine contains a K1 forged crank, scat h-beams, J&E SRP pistons.

If i were to do it again, i would still choose an engine builder as opposed to a crate or someone on the web.
 
Stock 289/302 blocks are definitely going to be stressed by 450+hp. I've seen them split in half at those power levels. A 351W build would be a lot easier with those power goals. Otherwise, look at an aftermarket block.

I have a scat high-nodular crank and scat forged I-beams in my 331. The one thing I'd recommend is to use ARP cap screw rod bolts rather than typical wave-locs. You may have to clearance the cylinder skirts to make them fit, but it's worth it to know that your rods aren't going to come apart at 7k.

Also, if you stick with the AFR heads, consider different valves and hardware. I've heard ARP uses substandard components, the valves specifically. A couple guys on Mustangforums have trashed AFR valves while running at high rpm with heavy valve springs.
 
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