Dad bought a 1937 Ford in excellent condition the other day. It was built as a drag car in the 60s by his cousin. It has hilborn mech. fuel injection, 11:1 compression, a crane roller cam and some other goodies. We are going to be doing some framework and we are going to build the engine again while we have it out. We would like to see 400-450 HP. Also, I have heard Hemis are more tolerant of pump gas than wedge heads and will tolerate higher compression ratios. Can we run 11:1 on pump gas with this engine? We won't be using the fuel injection unless we can get it converted for a reasonable price. We will convert to a distributor and electronic ignition as well. If anyone wants to see pictures I will post them.
As far as I know Hemi heads are LESS tolerant of pushing compression limits on pump gas due to the fact that the large open chamber has excessive surface area and zero quench pad area when compared to wedge heads...this is why the modern new current Dodge Hemi's are actually of hybrid hemi/wedge design....valves are across from each other like a hemi, but sides of combustion chambers are closed-in, having quench pads like a wedge head, and are not of the full hemispherical shape. Quench is an important aspect of performance on pump gas when pushing the compression ratio limit you can get away with.
Spend what you need to for the manifold conversion to electronic injection....there is nothing cooler than a Hemi with ram stacks.....Actually any engine with ram stacks
A good modern performance carb, and a single 4-barrel manifold for the First Gen Hemi will eat $1000...spend that on the conversion instead :thumbup:
Hot Heads is the company to talk to for the Vintage Hemi parts and tech.
A hemi can tolerate more compression since the flame does not need to travel across the piston. Add aluminum heads and you can go further. You can possibly get by with 11:1 using high octane pump gas - cam profile may affect cylinder pressure though. You can get off the shelf pistons of 10.5:1. It would be pretty easy to get 400-450, but you need to investigate head work and cam profiles. Better yet, sell the injection system and put a blower on it. Hemis respond very well to forced induction.
No numbers yet, but dads cousin built it in the 60s and we have the parts list he made for it. Says its a 354 and the Hilborn sheet says it too, but we will look at the numbers to make sure.
You heard that backwards, hemi's are more sensitive to fuel quality and octane, especially these early ones with no squish/quench band. Unless you use a lot of cam timing it isn't likely that eleven to one will run on pump gas, even 92-93 octane.
What you'll need to do is calculate the Dynamic Compression Ratio (DCR) which is based on the stroke used up at the point of intake valve closure. This has the effect of reducing the Static Compression Ratio (SCR) which is the classic calculation of compression ratio based the cumulative volumes of the cylinder and head with the parts and spaces between them. An old iron head hemi will need to be close to 8:1 DCR maybe a little under that.
If you live where E85 is available that can be pushed higher. You probably need to consider hard seat inserts if you're going to run unleaded fuels.
If you have 110 race fuel, you can add a few gallons to a 12-15 gallon gas tank, and it will give you some lead in the fuel, and up the octane to around 95, if you mix with 92 octane. I do this on one of my cars regularly, and it not only runs great, but the higher octane makes it run cooler too.
The 354 Hemi Red Ram or what ever its designation were all the same engine! H.P. ends were your money runs out , My old 354 I ran in the 60's with Hilborn short stacks and zoom headers was over 475 H.P. ! The 354 is more limited then the 392 and 426 in its output potential but is still impressive in its looks and torque and is very sensitive to octane ratings unless its still in its low compression stock configuration. The blocks are week as are the cranks for supercharging at higher boosts, or over 400 H.P. builds, but deep pockets can correct that (if you can still find the parts) swap cranks and With the 354's stock bore of 3.94, and the 392's crank stroke of 3.90, you end up with a motor that's almost "square".....or if you do a .060 overbore ( If the cylinder walls will take it, you end up with a low deck 392 that's close to 30-40 lbs lighter than the factory 392 with the taller deck.
It was a chore to keep my 354 together at 475 H.P. back in the 60s when the availability of parts were very easy to come by let alone now when they are scarce ! A 383 or 440 would be a better choice for a race build and parts are more abundant then any Hemi especially the 354! But a mild 354 in a hot rod is a very impressive engine:thumbup:
Here's one ( 354 in the pic) running 5# boost, ( at Crank ) 450 hp and 5000 RPM peek! and is very impressive on the street with cast pistons (K.B.s) and stock crank and rods and a mild B.D.S. Blower cam! It says Isky Cam on the hood But its a B.D.S. cam LOL!! It has never run at a track and would probably be in the 12s bracket but who knows that looking at it or when it does buen outs :thumbup:
With the 354's stock bore of 3.94, and the installation of the 392's cranks stroke of 3.90, you end up with a motor that's almost square and if you do a 0.060" overbore If the cylinder walls will except it , you end up with a low deck 392 that's close to 50# lighter than the factory 392 with the taller deck. We did that a lot in the early years But the 354 blocks early castings, when bored had a lot of inclusions in the blocks and cylinder walls ( Bad areas ) and when bored needed sleeving.
I am not here to start any arguing - but the old Hemis are tough and can take some abuse. The stock cranks are strong and good for probably 800 horse or more. Best to tie the lower end together either using 4 bolt mains or a girdle if you are going to run bigger power. I would not use anything stock except a crank and rocker assemblies if they are good. Definately get new valves, retainers and locks. Stock rods can be used, but for the price, I would get new H beam rods. These parts are old and fatigued. With the cam profiles available, HP comes easy. Get the heads to flow, compression at 10.5, and the right cam... you could have well over 450HP.
Basic rule is, a hemi will handle 1/2 to 1 full point of compression more than a wedge engine. And timing should not go over 30 degrees total unless the dyno shows differently. Hemis do not need a lot of advance.
These motors get expensive, so do your research. I strongly recommend talking to Bob at Hot Heads. Tell him what you have and what you want to have. He can tell you how it's done.
I currently have a 392, 8.2:1 compression, 10 lbs of boost. Stock crank, 4 bolt mains, bored .030, K1 rods, solid roller cam. This is street driven on pump gas. I do have water/meth that kicks on at 5-6 psi.
I had a 392 with just 2 4s, and that dynoed at 525HP, pump gas and not a very agressive cam (dont remember off hand, but think .565 lift, duration at 50 was arond 255-260). (some very nice head work done)
These old motors were put to the test. They were the only engines that you could pull out of a car, bolt a blower to it and run it with 80+ nitro and they lived.
Have a friend with a 354. He did use Hot Heads aluminum heads (ported), stock crank/rods and his dyno sheet was just over 600HP (I think it was 614??) This is also a street engine on pump gas.
Not Arguing with any ones experience with the 354s! But with my experience unbeefed production 354 blocks have adequate strength for normal usage about 400 to 500 hp on a 354, and 500 to 600 on a 392. Running more than 11.0 to 12.0:1 compression, or forcing in 8 psi or more of boost, or packing lots of nitrous or nitro makes the odds of grenadeing the cylinder walls and main webs very high on the 354 LOL. In the '60s, we used the old school support girdle for the two-bolt caps and filled the blocks with concrete for the strips, and half filled them for the street , they lasted a while but the 354 longevity was from race to race when it would fail was a guess and a spare was waiting to take its place. New four-bolt conversion caps have made girdles completely obsolete ! The 354 forged steel crank would usually crack through one of the center mains even girdled! The 392 and 426 cranks were better at taking abuse because of the larger main and rod journals, and the 392 and 426 had stronger webbed blocks and thicker walls, stock rods are only oK for most normally aspirated mild engine builds (but thats the owners choice :thumbup:
There was a reason the 354 was replaced by the 392, and later the 426 , The 354 would self destruct against the Chevy small blocks and Fords and even Mopars own small cube wedge engines, when that much H.P. and RPM was called for to stay competitive the 354s failed miserably!!!
I don't want to burst any ones bubble but the 354 is limited in power potential unless your pockets are deep, and like I said its a great looking engine and is great for a street machine :thumbup: with fair power potential! Those are my experiences and knowledge on the 354 as a drag engine, If you have one or find one, with the rarity of Hemis, and parts, Build it and enjoy it !:mwink:
Ran a 354 in a 33 willys nostalgia blown gasser for 15 years.
Blown gas, 20lbs of boost, stock crank, stock rocker arms. Made over 400 runs in that car. Car went 8.80s @ 150mph.
Never broke a block, never broke a crank, never broke a rocker.
Most guys will attribute the first 1 hp per cubic inch motor to Chevy, with the 283 hp fuel injected 283 in 1957, but Chrysler did it in 1956 with a 354, 354 hp. More compression, 2-4 bbls.
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.
Related Threads
?
?
?
?
?
Hot Rod Forum
2.2M posts
175.6K members
Since 2001
A forum community dedicated to hot rod owners and enthusiasts. Come join the discussion about restoration, builds, performance, modifications, classifieds, troubleshooting, maintenance, and more!