392 to ????
 

I'm a long way from having to do anything but the "How Much Is Too Much?" thread got me thinking about what I would do when it's time to work on my engine. Currently, I have a Ford Racing 392 with 4 - 48 IDA Webers. The engine with a 750 Holley and Victor Jr (which I still have) supposedly makes 475 HP. Haven't put the car on a dyno so I don't know what it makes with the Webers. From here, would you go to 402/408 or all the way to 427? Stay with the Webers or go to a 4 - barrel? Maybe go with a multi-stack FI setup? From the other threads about Webers, apparently the 48 IDA won't make over 500 HP but I like the linear pull. Is a muti-stack FI setup limited HP-wise for the same reasons as the Webers? When I'm around other cars, I always end up with cam envy since the Webers smooth out the lope and won't tolerate a lot of overlap anyways. On the other side of the coin, my current setup is very streetable and still provides excellent power. So many choices. What would you do?

move up to a big block....427 with webbers....you will kick yourself in the wallet for not going that way to begin with......

No need to go to a BB to get 427 ci.

It all depends on what you want to do with the car as was detailed quite nicely in the other thread. Will your weber set up work well with the Z cam in your crate engine? I had the 430hp version of that engine in my FFR coupe with stack EFI and it was amazing. The initial and mid-range acceleration was intense. Where it suffered was at upper rpms where the lack of a common plenum caused it to run out of air (so yes to that question). I think you will see the same issue once you sort out the tuning. Hopefully, Bob will chime in on this as he has an EFI stack set up and runs it at the track with great results.

Personally, I like a big displacement small block for any driving requiring great handling which is what I enjoy. My Kirkham FIA has a 540hp 427w.

thats true.....but you can go well over 500 inches with a big block.....

I had the same thoughts as you. I tired of the 392ci and felt it was not up to its game, so i went more extreme and went 445ci SB.

It all depends on what you want to do, i wanted both street and track and planned on back of that.

Enjoy and good luck.

Skippy.

Muscle Mustangs and Fast Fords got 537 HP out of that bone stock crate 392 with just a head swap, AFR 185's. It also put out over 500 lbs/ft of tq. The heads are $1500 bucks. So, if money is an issue (and it always seems to be), that puts you within 3 hp of the 427ci. If you have tons of dough, go with the big block and you can pick whatever power level you want...

408
408
408
408

Dwight

Jeeeesh. I think I jinxed myself with this thread. I made an early exit from the Chin Motorsports event at Sebring this morning. I went three laps before I got the meatball flag. Went to the pits and found I was spewing coolant and motor oil. Upon further inspection, I suspect blown head gasket. After I shut down the engine and opened the hood, steam was squirting out from the back of the engine, right at the head the best I can tell. The only reason I don't think freeze plug is because of the oil. The odd thing is it never ran any different and temperatures were fine. No missed shifts, never hit the rev limiter; in fact, I don't think I ever had it over 5,500 RPM. Even the instructor said I hadn't done anything to cause a blown gasket. Coolant and oil were fine before I hit the track but oil was down about 3/4 of a quart and the expansion tank was empty when I shut it off, so I'm guessing maybe a shaky build by Ford Racing? Engine has 1,059 miles on it.

Ford Racing is an assembly line based program. You will never get the same quality build as you would from an individual builder.

If I were in your spot and were bent on street driving, I would upgrade the cylinder heads and camshaft, then go with a longer stroke.

If you were planning on doing some road racing, then I would keep the same stroke and do the same head/cam upgrades.

digginfool, if you didn't tear too much up i would try to replace the head bolts with studs and retorque. save the summer drivin' season. new engines might need a retorque if that wasn't done. i fixed a 351 crate engine with the same problem, check your radiator tubes to see if they haven't been blown out.

i can give you specific instructions if you would like to try it.

That's what I told my wife; head bolts probably came loose. Do you think it would be prudent to check the bottom end or replace the gasket and go (not to mention loose the bolts and switch to studs)?

if it was my junk i would do a leakdown test on all the cylinders, see how bad they are or how many and make a judgement call, then maybe replace and retorque the bolts with studs, then do another leakdown test and see what happens.

i'd do this before anything and make a judgement call at that time, the studs are going to cost you no matter what and the leakdown test is just time.

An engine of that caliber shouldn't need head studs, bolts will provide enough clamping force.

Also keep in mind that if you switch to studs, it could cause a different area of cylinder wear if the block was honed with a torque plate and regular bolts (or without a torque plate at all.)

I would make sure that the head bolts have not backed off, then do a leakdown test as Vector said.

Intake gaskets can really screw things up too....especially if something like a Felpro Printoseal intake gasket was used.

That's what I love about my set-up. The torque is incredible with the Webers. The power delivery is very linear; no big top-end rush like you get when the secondaries open. Just linear power (and LOTS of it) until it's time to shift. I haven't really noticed any roll off but I tend to short-shift around 5500 RPM or less anyways when I'm running it 'hard.' I guess I could be shifting at that range because that's where the seat of my pants says it's time rather than taking it out to redline.

be careful if you decide to turn the engine over you don't do a hydrolock. remove all plugs first!

As soon as I suspected a blown head gasket, the key to the battery cut-off came out of the car and we pushed it into the trailer. Not about to take that chance. It won't turn over again until the engine's put back together. Somebody on another board suggested that the block or the head itself may not be true and that may have led to the failure. Any thoughts?

I'm betting on loose head bolts. Not only have I seen it on several FRPP crate engines, but it is the lowest cost cause for you!

Amazingly enough, the trouble was a freeze plug on the back of the head that popped out. The 'oil' must have been some sort of sludge in the cooling system (wetting agent?). Replaced the freeze plug, refilled the cooling system and all is good, at least for now. I let it run for about a half hour then took it for a ten mile drive with no problems. I initially considered freeze plug until I saw the 'oil' and another person said steam came from the exhaust. In any case, I hope this is the end of it.

Sounds like you dodged a bullet on that one!

As for the engine, a lot depends on what you plan on doing with it. Unless the car dedicated to a specific purpose, everythings a bit of a comprimise.

Any stack system (EFI or Webers) will cost you a bit at the top end. Without a common plenum, it's a little more difficult to force feed the cylinders. But, you get greats looks instead. If I was building a dedicated track car, I would not use stacks or webers. But for a street or mixed use car I think they're awesome.

EFI is the way to go, IMO. Nothing like modern technology to make your life easier. I live at 6,400' ASL. My car runs just as well at 10,000' ASL in cold weather as it does at 4,500' ASL in hot weather. The computer senses the changes and adjusts accordingly. Last year we raced in Tulsa, 850' ASL. We didn't have to make any changes at all. Drove it off the trailer and onto the track. Computer did it all for us; and the car ran great all week end.

Fine tuning is pretty simple. Connect a lap top and tap a few keys. No buying jets, emulsion tubes, choke tubes, etc. You can make changes while your strapped in and driving down the highway. The newer systems use a wide band O2 sensor, so the computer makes those adjustments for you. Regardless of the system, the initial tune should be done on the eddy dyno with an experianced tuner.

Selection of cam and heads is critical with stacks. If the heads and valves are too big, you lose intake velocity and your low end power drops like a stone. The wrong filters can cost you a lot of power, too. The traditional tea strainers cost me 100hp on the dyno.

The camshaft can be a little tricky, too. A wider LSA will really reduce reversion and increase chamber filling. Simply increasing the LSA will give more power and efficiency.

I use a cam that pretty big - just about the biggest hydraulic roller in the comp cams catalog, with 114* LSA. Makes excellent power, a very flat torque curve, and drives around town with not trouble at all. The car is easy and fun to drive on the street, with no bad manners. But when you mash the throttle, it screams like a banshee and takes off like a rocket. It's easy to drive on the track because the torque curve is so flat; I generally use only 3rd and 4th gears. Last week end I shifted only twice per lap- once from 3rd to 4th, and again from 4th to 3rd.