392 Hemi
Moderator: Team
392 Hemi
I get on the HAMB hot rod site frm time to time ..Many guys there go on and on how the first generation Hemi is so powerful...How much power can a 392 make on pump gas and be a tolerable street engine?
Motorcycle land speed racing... wearing animal hides and clinging to vibrating oily machines propelled by fire
Re: 392 Hemi
How much money you got?
Heat is energy, energy is horsepower...but you gotta control the heat.
-Carl
-Carl
Re: 392 Hemi
Not enough, lol. Supercharged(screw)/Intercooled IAT under 130f you can make 2:1 hp per cu in Hemi, 87 octane
Heat is energy, energy is horsepower...but you gotta control the heat.
-Carl
-Carl
Re: 392 Hemi
I'm interested in N/A, one or two four barrel carbs,a hot rod engine. cam, headers, good valve work,etc.
...I'm thinking 450 hp from a well tuned first generation street engine
...I'm thinking 450 hp from a well tuned first generation street engine
Motorcycle land speed racing... wearing animal hides and clinging to vibrating oily machines propelled by fire
Re: 392 Hemi
Not a problem with a good intake and exhaust, keep the stepped exhaust, small to big. 1.5 to hp/cid fairly easy with good planning. The hemi chamber is very forgiving to octane. Cam events are critical too especially rpm and exhaust tract.
Heat is energy, energy is horsepower...but you gotta control the heat.
-Carl
-Carl
Re: 392 Hemi
Most if not all older bikes have true hemi chambers...They are not forgiving to octane and detonation can be a problem on pump gas even on stock engines...Yes they are air cooled ...
Motorcycle land speed racing... wearing animal hides and clinging to vibrating oily machines propelled by fire
Re: 392 Hemi
They are very forgiving to octane, what they are not forgiving to is preignition. Bro, I know you know what you're doing. 2tc toyota in the early 90's and many 1000's of hours on the dyno is how I was playing. There is no way to scavenge the cross flow hemi chamber, so all you have left is to control the combustion of said leftovers.
Heat is energy, energy is horsepower...but you gotta control the heat.
-Carl
-Carl
Re: 392 Hemi
Even though your hemi experience is air cooled, you probably know as much about potentials as most HAMBurgers.
There's a lot of real world experience on any obsolete engine on the H.A.M.B.; sifting it out is the challenge. The guys-who-know get buried among the dozens of wannabee replies to any thread and the dozens of threads per hour.
In my limited experience years ago, street-drivable-normally-aspirated hemi power peaks early. As you know from your Triumphs, as compression goes up, the combustion chamber shape goes large-area-squished pancake and the piston dome gets in the way of breathing and spark. Flattops down in the hole were one reason the early hemi ruled blown fuel. Once the NHRA banned fuel, the SBC was all over the early hemi.
Jack Vines
Studebaker-Packard V8 Limited
Obsolete Engineering
Studebaker-Packard V8 Limited
Obsolete Engineering
Re: 392 Hemi
Yes, the dome used in a hemi chamber is a bad thing, flat dome always makes more power even with less compression, regardless of cam timing. This was 18:1
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Heat is energy, energy is horsepower...but you gotta control the heat.
-Carl
-Carl
Re: 392 Hemi
In case anyone is wondering about the cut pipe in a couple pictures, that's what I found in the backyard to make my tapered sleeve and ring squaring tool out of.
Heat is energy, energy is horsepower...but you gotta control the heat.
-Carl
-Carl
Re: 392 Hemi
What is the application? A '57-'58hothemiheads.com392" weighs about 765# and is wiiide. The Hot Heads guys have a lot of good aluminum heads, intakes, water manifold, et al, to get the weight down, but it's an expensive build. The other problem is finding a good core is almost impossible. I haven't seen one in years.
hothemiheads.com
Jack Vines
Studebaker-Packard V8 Limited
Obsolete Engineering
Studebaker-Packard V8 Limited
Obsolete Engineering
Re: 392 Hemi
Jack, it's just a idea right now....I can see 10 grand won't go very far...PackardV8 wrote: ↑Mon Jul 19, 2021 4:08 pmWhat is the application? A '57-'58hothemiheads.com392" weighs about 765# and is wiiide. The Hot Heads guys have a lot of good aluminum heads, intakes, water manifold, et al, to get the weight down, but it's an expensive build. The other problem is finding a good core is almost impossible. I haven't seen one in years.
hothemiheads.com
InTech, pistons I use in the race bikes, 10.5 compression, flatter top , a narrow squish band around the piston about .032 clearance. On street bikes about 9.2 compression, 100 degree intake lobe center, runs ok on 91 octane You can see the squish band in the photo
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Motorcycle land speed racing... wearing animal hides and clinging to vibrating oily machines propelled by fire
Re: 392 Hemi
Hiya trucked, I've been out of the toyota game for a while. I talked with Mike about doing some tight lobe center stuff but there just aren't any UGL cores around anymore. It was fun to play with
Heat is energy, energy is horsepower...but you gotta control the heat.
-Carl
-Carl