Technical 241 Hemi Valve Springs

Getting my 241 torn down so that I can take it to the machine shop for prep. Upon tearing down the heads we found that the heads have duel springs. Not dampeners but actual springs. This motor was pretty much a core however it has been opened up in that it’s .030 over. Anyone see this before?

 

Dart4forte. Sounds like you have my engine! I’m running a 241 with dual springs on the head. Bored .030 also. My old heads, stock, had dual springs as well

 

Every 241 I have been around came with dual springs I've run Edelbrock 5822 springs now discontinued they were for a 289 302 ford.

 

All early Hemis came with dual springs. Measure your spring pockets & match up the installed and bind points, spring pressure, ect. and match it up in a spring catalog. On my 331 Chr I use Comp Cams springs, no idea what they're supposed to be in.

 

Yeah, I have a new set of comps. Interesting they used duel springs

 

This motor will be .060 over. I cylinder was ugly so rather spending the money for one sleeve we decided to do the overbore and order pistons accordingly

 

Hopefully forged ones with decent C/R. The advertised C/R was 7-7.1:1, but one measured out at an actual 6.19:1!

 

Went through Gary up in Bend Oregon. Special ordered. I’ll know the exact CR when I get the block and heads back cleaning and shot blasting. Shooting for around 9.5 to 1

 

Gary at QEC is a great guy, if that's the Gary.

 

The Compe***ion Products catalog has springs height by installed heights and diameters. Retainers and keeper have different depths to set them where you want. If a street engine flat tappet either hydraulic or solid I would stay under 100#. 70-75 was probably stock.
Rollers would be near 150# for the street…. Racing your on your own.

 

Like Jimmy says pick your cam, pick the springs recommended by the cam manufacturer. Or set your own spring pressure. I have run BBC springs on an early hemi. Just have to cut the spring pockets. Crane use to make a cutter. Get a height mic, and have fun. Remember, it depends on the spring rate. A lot!! Different springs even though they are the same diameter vary a lot between seat and open pressures depending on cam lift and spring height. If your gonna experiment, find a buddy with a Rimac spring tester.

 

Lippy, I bought a spring tester that could work in a vice or with a drill press and made PVC tubes at .010” intervals to check springs. I bought an valve mike also and found keepers with different knotch heights to get installed height of the springs. Everything was relatively inexpensive. With shims I can set all of valves within 5 psi or better. . I like to play with my racing engines but do stockers the same way.
I’ve found cam grinders recommended spring values are normally too high for me. Only my sons dirt track flat tappet engine sees 7000 rpm and it gets 135 on the seat.

 

Yes

 

You can widen if you must, but don't cut any deeper, casting is a bit thin...

 

Valve spring tester get a digital bathroon scales a old valve and your drill press chuck the valve set the drill stop at the height you want and go

 

John and George; thanks for the nod! Much appreciated.

The EarlyHemi's valve springs can be pulled out of a catalouge as long as you keep within the basic architecture.
I have found that for many applications, with street cam profiles, the Mopar 360-2V spring is a great replacement that fits the oem space. You get to decide what a street cam profile is.
If the valve lift is kept under .500 then cutting the pockets for tall springs or using tall valves is really not needed and only adds to the costs and mucks up the rocker geometry.
Personally, for a lot of basic rebuilds, I use 80-100# on the seat and about 250# open and it works well.

 

Thanks Gary, good info on the 360 springs. Not sure on my cam however it will be well under .500 lift.

 

Without going to a billet cam we are stuck with 1/2" as a general maximum on regrinds so your spring options are numerous.

I have gone well past the 1/2" mark on builds using non-modified rockers and found that the rocker tip does a lot of sliding across the valve tip, and not necessarily gracefully...
Lash caps would help but they consume space themselves. My personal history says to modify the rocker stands when using a big lift cam or, keep the lift in check and add to the duration to compensate. Obviously, the better way to get high lifts is to spring for 1.6 rockers but that only works if you are working on a Chrysler; nothing available for Dodge and DeSoto.
Whatever you do just pay attention to coil bind.

 

While on the subject of valvetrain I’m wondering what size valve to use. Don’t want to go too big because of shrowding and I don’t want cut valve reliefs in the cylinder. I have some 1.88 stainless intake valves that can be cut down.

 

The high deck Dodge heads will work.

 

I have a 270 that is running 300 ford valves but they require 11/32 guides the valves were Milling V1120 intakes and V0965 exhaust used in 300 Fords 1965-74 guides are available from Hot heads

 

Just like valve springs, sometimes just trolling through a valve catalogue and comparing the measurements will yield a suitable valve. In the past we have used some generic gm pieces in the 241-270 heads.
The length is the most critical number as the installed height is the hardest to change; heads can be trimmed and guides can be changed.
Be cautious about the valve seat position; sinking the valve in a Hemi usually screws up air flow.

 

Yeah, he’s done several early hemis including a 241. Just have to see what recipe he used on that motor. My 241 isn’t going to be a race motor however going to go in my 52 Dodge and I’d like some giddy up.