Technical Just how much HP will a 4 bbl add

Kinda applies to some of the other comments up for discussion on this thread doesn't it?

 

I'm gonna go ride my engine cycle

 

General Engines
Ford Engine Company

Wait, what?

 

You can't cool air? Of course you can it's simple physics. Compress air and it heats up. DEcompress air and it cools down. The theory is simple, Google air cycle machines.
I don't get what your saying about one sided thinking. I was just pointing out what the aviation industry uses as a standard.
World wide.
If you want to call your hemi a motor that's fine with me, and yes, most do.
Personally I'm in awe of hemis since I was a teenager and my buddy had a 68 426 Charger. Black of course.

 

I am kind of going through a similar thought with a Y Block I am about to get rebuilt. Before I took it out, it went great with the original 2BBL, with the rebuild do I get a bit more of a cam and go 4 barrel? Nothing over the top. I will probably start a new thread about the rebuild soon anyway so junkyardjeff can get back to business here.

 

I think this thread is about done,just wanted to know about how much could a 4 bbl increase the hp of a 2 bbl motor and heard about everything else.

 

In 50 years of playing with motors (sorry, ENGINES) I have never seen a 4bbl swap cost power. Sometimes a mis-matched carb made one engine a bit balky at low RPM, but they all came alive at medium to high revs. That goes for 235 Sixes on up to 390s and the like.

 

It costs the same for the factory Chevrolet 365 HP valve cover stickers as the lower HP ones.....It impresses the yahoos that look at the 160 MPH speedo and say that car will go 160 !!!!

 

You are exactly correct, there is no such a thing as cold only the absence of heat.

As for motors V engines, if common semantics (linguistics) isn't good enough there is always the war engine also know as a siege tower. I did not move under its own power and in most instances we would have called it a trailer. it often had no moving parts what so ever, it was just a tower, and sometimes it didn't even have wheels it was built on site.

Fun argument, no one can win.

 

Well We just won ******!

 

Well, a siege engine converts one form of stored energy into another right? Like converting tension into flinging big rocks, huge buckets of cow****, and rotting corpses over walls...
that's sorta like converting fossil fuels into heat, and turning some of that heat into rotational power, right?? And properly applied, both can be a whole lot of fun too!

 

Engine Masters did a nice little comparison.

 

Funny when I was little it was motor sackle (SIC).

After I grew up I thought that I called it that because I was a little kid. A while back I was talking to a man who I have known pretty much as long as I can remember, he is about 16 years older than I and was a good friend of my old man. he was telling me that he was going for a ride on his motor sackle.

 

I didn't read every reply in this thread but.........
How much will a J2 like this really add to a 371?

 

A trebuchet, also called a catapult was also called a war engine. But came after the fact. Some of the earlier examples were not more than something like this and the energy that was expelled came in the form of man power, climbing, jumping, shooting a bow etc. the tower itself was little more than an enclosed ladder.

Tony,
I am not an Olds expert so what I say may not amount to a hill of beans. But I think that the J2 package was more than just tri power. I would to look at specs for comparison but I think that the camshaft and the heads were different too.

I think that sometimes when we are measuring by the seat of the pants we mistake a difference in performance characteristics for added power. A lot of the time a 4 bbl has smaller primaries than the 2 bbl that it replaces. So what happens is that it is a little snappier on the bottom than the engine was with the stock2 bbl and after that begins to play out the secondaries kick in. We have not created more power we have just changed the way that it comes on.

 

Engine? Motor? Isn't it an internal combustion engine motor? Doesn't a motor just convert energy into work?

I'd have to think that engineering aside, that 371 really could wake up big time with a 4bbl added. More in, more out. Pretty simple, no? As to how much, pick a number. A time slip will do it for you given the right math and removing the "hard on factor" from the end result (variables like wind, traction, etc). I once did a simple wt vs performance test in a car that was 1000 lbs lighter than my racer. Testing the theory that every 100 lbs was worth 1/10 of a second. It actually worked out very close but we fought a 30 MPH headwind that day. Once traction, launch and shift point was worked out we were a tenth better than the estimate. The math said that at the time I was making 685 HP, and it took that much to run the other car the ET that it ran, but the MPH number was even better. Always wondered what would have happened without that wind. Testing doesn't lie and beats even the best guess.

 

Basically a runner length/CSA/plenum volume test, I would be VERY careful drawing conclusions about anything but those EXACT intakes on a 470hp-ish sbc from this test. Yea, I know, I'm no fun at all...

Well yea, but admit it. Trebuchets are WAAAAY more fun!

 

You are absolutely correct. Even the minis that only throw marbles are fun to play with. I cannot imagine the giggling that tossing a Honda would create.

Sooooo when Edye and I move out to the country place (I promise not to teach the girl bad habits (on purpose) ) are we building one of those?

 

We have too many trees in the way, we would have to fling it really high!

 

The J2 only fit the early 371 motor built in 57-58. It won't fit on the later 1959-60 371, as they are different design on block/heads/everything...

So on the 57-58 here are some specs: First number is compression ratio (which you can see went up in 58) then next number id Horsepower , and then torque.

1957
88 V8 9.50 277 @ 4400 400 @ 2800
88 3x2 Carb J-2 V8 9.50 300 @ 4600 410 @ 2800
Super 88 V8 9.50 277 @ 4400 400 @ 2800
79,693 98 V8 9.50 277 @ 4400 400 @ 2800


1958

Dynamic 88 10.0 265 @ 4400 390 @ 2400
Dynamic 88
3x2 Carb J-2 V8 10.0 312 @ 4600 415 @ 2800
Super 88 V8 10.0 305 @ 4600 410 @ 2800
98 V8 10.0 305 @ 4600 410 @ 2800

 

Hey F&J,

Thank you!

 

Here is what I can tell you. In about '96 I built a car to run in N.H.R.A. stock eliminator. '67 Dodge Coronet 383 2bbl. for J/SA. The best I was able to get out of it was 12.80/104 @3625. Towards the end of the season I decided to put a stock 4 bbl. intake and a AFB from a '67 440. Changed nothing else just tuned it. 12.45/108. Rule-of-thumb in the drag racing world, 10hp equals one tenth of et. So I guess it was about a 35hp gain. Kept the car in G/SA after that. Gene.

 

I think the regular J-2 used the same cam as the 4v motor, the so-called "export" J-2 had solids. Is that basically correct Frank?

 

for 57-68

Yes, I forgot I was going to add that info: The J2 for normal customers was only the added carbs. And, the non-sellable/leftover J2 engines had the outboard carbs not installed, and Olds made block-off plates....and these were sold to the public in cars listed as 2 barrel cars...to unknowing consumers.

I know where there is one of these manifolds with the plates still there.

The Nascar or "export" kit, came with solid cam, adjustable rockers, dimpled painted valve covers, different valve springs and possibly retainers, as well as the thinner headgaskets to raise the comp.

I have a 57 and a 58 parts book from Olds, but I never saw one piece of the Nascar/export version. Either these were only listed in some special parts book, or maybe the dealers never had the part numbers....just the racers? IDK

I still wonder about the aluminum cam tag I found at the "Olds Farm" for 57-58. It has an untraceable part number, other that a note in the January 1962? parts book showing this number in the "deleted" section. This tag mentions new springs/retainers to be used with this cam. It might be just a recall type replacement, because I read something about cam failures in 57-58.