Ok so this is my first time posting outside the big bronco forum, and I have a very limited knowledge of all the math and stuff that goes into figuring the power output of an engine. My 351 has 205000 miles on it and runs perfectly, but i'm trying to get a plan toghether for when its time to be replaced. Other than some bolt ons ( throttle body, K&N FIPK, electric fan conversion, ect) its completly stock. I want a minimum of 325hp, it has to remain fuel injected, street legal, able to pass emissions, NA, and if possible run on 87 or 89 pump gas. Can someone point me in the right direction as far as what it takes to get this amount of power out of this engine?

 

if it's getting a complete rebuild I would stroke it to a 393 it's cheap and easy and will up the torque number big time.......

AFR185 heads
rpm intake
750vs holley
cam???something in the 220@.050 duration..I would call a custom builder myself....
long tube headers

should put you way over your goal with out spinning it to the moon.

have a good one and good luck.....

 

Couple more questions

1. if I have have it stroked, I'll have to run premium fuel won't I?

2.I don't want to offset the lifetime of this engine too much for performance.

3. I know a lot of people disagree with this, but it has to stay EFI, i don't do carbs. I'd like to stay within the limits of speed density to get the power i'm after, but I can make the swap to mass air if I have too.

4. I have never bought a new engine, so I have to ask, since I allready have a 351, should I have my block rebuilt or is it cheaper to get a crate engine or long block and and put it in myself?

5. Are there any crate engines or online places you would recommend?

6. I have the money to spend, but I'd rather not pay too much for such a "mild" build, is it worth buying some aftermarket heads and a intake, or will having the stock ones ported and upgrading the cam and valvetrain get me into the 300 HP range?

7.I'm sorry if i'm getting all off subject, but internal engine stuff is the one thing I haven't messed with yet. My main focus is to get some more "get up and go" out of the new motor. I want to make sure this thing stays street friendly, and has a good idle quality. The thing is allready a torque monster for stock, so i'm not all that worried about that. someone let me know if i'm just way too off..............

 

If you have the time and can live without driving your truck, I'd say you should rebuild it yourself. Or find another block to rebuild and swap it in so your truck has less downtime.

It will be cheaper to rebuild it yourself, since you will only be paying for the parts and not labor (except a couple hundred bucks to get the block and crank ready for the rebuild). But aside from the cost, I think rebuilding it yourself is a good experience. I'm rebuilding my first engine right now and I love it. I had a good idea of how engines worked before, but once you have to take it all apart and put it all back together, you have a better understanding and appreciation for how it all works together.

Another plus of doing it yourself is that if you take the time to do it right, you know it was built well and didn't skimp on anything.

 

a 'stock' crate engine will cost about the same as having it rebuilt.

 

Yeah, but if he is wanting a minimum of 325 horses, he isn't going for a stock rebuild.<hints id="hah_hints"></hints>

 

Sad fact is that you won't see 325hp with a SD computer unless you pay the $1000 for tweecer and the tweecer harness (plugs in between the engine and the ECU). You'll also need a laptop for configuring the ECU to run correctly. A longer stroke doesn't mean you have to run higher octane fuel, it just means the pistons travel farther down in the cylinders. If you raise the compression from stock you might need to go to a higher octane fuel.

 

But when stroking the engine you raise compression. The stroker 351w I am building required the use of 22 cc dished pistons to get compression under 12:1 with the use of 58cc combustion chambers.

But a 351 is the easiest to stroke though I would recomend going with a 3.85" stroke a stock 5.956" connecting rod and a piston with a 302 compression heigth on the piston. There are different ones so you would have to figure out how close to the deck surface you want the piston and go from there. But with the right camshaft, and a stroker route you can easily get 400 hp out of the engine and still have it under 10:1 compression where with aluminum heads you can run 89 or 93 octane depending on the exact compression ratio and the timing of the engine.

But like was said before your main problem will be the computer. The computer wont support more than the stock hp figures so you will have to change the computer programing basicly to get the power you want.

 

I built a 351W that sounds like it would fit yuor application. I ran a stock crank and rods, reinforced with arp bolts, added a main cap girdle, and a melling high volume oil pump. KB hyperutechtic pistions with moly rings, and a 15 cc dish- witha 69 cc cylinder head chamber you run about 9.0:1 compression. Helps with the get up and go the pistions will cost you around 400 bucks. Heads- if you have a good set and know someone that knows how to port you can get gain a lot of pep here and still have stump pulling power. Put in new polished valves and get some shorty headers and open the exhaust system a bit a dual 2.5 inch would run nicely. Find yourself a nice cam. I was running a comp XE 262 hyd. flat tappet- but you are running a roller cam so look at the similar cam from comp. This motor in my 1970 3 speed F100 was a really peppy runner. I could pull burnouts all night long, and it kicked the **** outta all the stock chevy 4x4s that are running aroung my town. Matter of fact I smoked my buddies dad in his 87 shortbox 454 powered truck. I had the short block professionally built and then bolted on the heads and intake, oil pump, carb, ignition system, headers, fuel system. Its a good way to get to know your motor and you get a solid rebuild, and save yourself a couple hundred bucks at the same time. That and there is nothing like firing up your first rebuild, put a grin on my face thats for sure.

 

You can get the HP you want, but there won't be much of the original engine left. The stock heads will only flow enough for about 275-300hp(at the crank), porting and bigger valves doesn't buy you much more. But there are losts of aftermarket heads that will once combined with an appropriate cam and intake system. A mass air computer will be the better starting point, and even that should be tuned for best performance and emissions. You could stroke a 351, but it's not necessary for 1hp/cu inch territory. I see no reason why a 351 with AFR heads, Trick Flow or similar intake, and a HO or E grind cam couldn't do this on regular pump gas.

 

Take a look in here (just to give you an idea) at some of the kits they sell. The 393 rotating assy. are cheap....

http://www.dallasexportsales.com/RA393W.htm

Crank: New Nodular Iron, 3.850 stroke
Pistons: Hypereutectic -22cc Dish 9.5:1cr w/64cc
Rods: 5140 Forged Steel I-Beam, 5.955
Bearings/Rods & Mains: Clevite 77 'P' bearing
Balancer: OEM elastic style 28 oz.
Flexplate: SFI approved 164 teeth, 28 oz.
Balance: High performance street/strip,
piston and rods matched +- 1 gram
$1,575.00 now $1295.00

put some good heads (not too big) on this and a cam that will pull to 5000 and you will love it.....

sorry i'm bored and was looking around at stroker kits...Some day I'm going to stroke my Clevor to a 408.....

 

I can do the mass air swap, i'll have to read up on the proceedure again, but i'm an experienced electrician, so no problems there. I do allready have a hypertech chip for the SD ECU but i'm not using it right not. I allready have an upgraded intake and free flowing exhaust system, and I have electric fans. So if upgrade to better heads, intake, and cam you think the 300hp range is possible? What kind of places can I take the ECU to for tuning? What about idle quality?

 

The hypertech chip won't help you. You need to have the whole vehicle dyno tuned once it is assembled, not just the ECU. This in not something you can mail order. I'm guessing you are in Texas, there has to be lots of hod rod shops around tuning mustangs.