Valve springs for howards cams

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scott657

scott657

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Just doing a little research, I noticed Howards doesnt have springs on their sight
and summit doesn't give any as suggested parts. Id like to use a single spring if possible
711451-08
Year:
 1964 - 2003
Make:
 Chrysler
Engine:
 273, 340, 360
Camshaft Type:
 Hydraulic Flat Tappet
Basic RPM Range:
 1800 to 5800
Valve Lift Intake:
 .506
Valve Lift Exhaust:
 .506
Duration Intake:
 267
Duration Exhaust:
 267
Duration at 050 Intake:
 220
Duration at 050 Exhaust:
 220
Lobe Separation:
 108
Intake Centerline:
 104
Firing Order:
 1-8-4-3-6-5-7-2
Quantity:
 1 Each
Country Of Origin:
United States
711381-10
Year:
 1964 - 2003
Make:
 Chrysler
Engine:
 273, 340, 360
Camshaft Type:
 Hydraulic Flat Tappet
Basic RPM Range:
 1400 to 4800
Valve Lift Intake:
 .479
Valve Lift Exhaust:
 .494
Duration Intake:
 255
Duration Exhaust:
 261
Duration at 050 Intake:
 208
Duration at 050 Exhaust:
 214
Lobe Separation:
110
Intake Centerline:
 106
Firing Order:
 1-8-4-3-6-5-7-2
Quantity:
 1 Each
Country Of Origin:
United States
 
#995 Comps are used on their comparable cams.
 
Last edited:
I don’t know who gave the approval for the Howard’s site, but imo it sucks.
At least the mobile version does.
 
I just checked the Comp site on my phone....... equally crappy to browse through cams for specific families.

Edit- You can download a PDF of both the Howard’s and Comp catalog........ which are much easier to browse thru.

Downloads | Howards Cams
 
JoePole1 said:
Which heads are you using?
Click to expand...

Good question.

In this case, since the OP is using aftermarket heads that use a taller installed height than the factory heads, the recommended springs won’t be the best fit.
You’d have to look at the specs of the recommended springs, then find something with similar load specs that will be a better fit for the different installed height.

Stock heads have a nominal 1.650-1.700 installed height.

SB Mopar RPM heads have a nominal 1.800 installed height.
 
Download the Howards catalog.

They call for springs PN 98438. Dual springs. But as said, the height won't be right. So look at the installed seat pressures and the rate for those recommended springs, and match those parameters for the taller installed height.

That cam has the note that it takes advantage of the .904 OD lifter size so is a bit steeper ramp than many. So a better spring that a simple single spring is to be expected from the mfr.
 
Just trying to make a square peg fit. I have other good recommomdations on another thread that will fit my parameters. I dont want to start another thread for the same answer.
I m no expert but with all the reading from you well read guys I really like some of the howards and hughes grinds for lift. letting my eddys work inn the lower power band.
 
nm
using the larger lifter does not require a steeper ramp
in fact you can use a not so steep ramp and get the same place
it's the radius of the lifter and using more radius that makes the difference
for example

udharold used exactly the same polydines and factors/ parameters for both the Lunati chevy and mopar cams, same accelerations
He used far fewer polydines for the comp xe versions as few as 4 for the shorter symetrical lobes- Ultradyne lobes are somewhere in between
That's why the Lunati lobes are quieter
 
i actually went through the catalog, then emailed Howards. got a different reccomondation . Then I found an edelbrock spring that fell right in the middle
 
Some say Howards recommends too much spring LDK
I'd jump over to Hughes and see what he recommends for that same duration @.050 and lift cam
Do you run spring seats? If so and a single spring you could break in without the seats then put them in
I'd look at a beehive spring for the 1.8 spring height- is that with or without a spring seat
Lunati has some good prices on springs I found some PAC beehives there recently
 
Howards recommended Spring kit #98113-K12 Beehive 108#@1.800 329#@1.265
Edelbrock 8525 128# and 339#
Howards catalog for the cam I'm looking at is dual spring 122# seat and 353#open
By the way cam is Howards 711451_08 506/506 lift

The ones on the heads now are eddy 5767 105# seat and 320#
They actually look closer than the behive spec from howards
I am trying to do this with no machining.
 
So I like this Camshaft
Howards Cams Hydraulic Flat Tappet Camshafts 711451-08
Calls for these valve springs on sight
Howards Cams Performance Mechanical Flat Tappet Valve Springs 98438
Howards tech support calls for these springs
https://www.summitracing.com/parts/hrs-98113-1
I have these on my heads now
Edelbrock Sure Seat Valve Springs 5767
Or I can swap these in
Edelbrock Sure Seat Valve Springs 5825
Will one of the edelbrocks support this camshaft
By the way the hughes 1110 matches the edelbrock 5767 almost perfectly
If the Eddies will work I will go with this cam if not I will punt and go back with the compXE and stop pestering you guys(on this subject):thankyou:
 
scott657 said:
So I like this Camshaft
Howards Cams Hydraulic Flat Tappet Camshafts 711451-08
Calls for these valve springs on sight
Howards Cams Performance Mechanical Flat Tappet Valve Springs 98438
Howards tech support calls for these springs
https://www.summitracing.com/parts/hrs-98113-1
I have these on my heads now
Edelbrock Sure Seat Valve Springs 5767
Or I can swap these in
Edelbrock Sure Seat Valve Springs 5825
Will one of the edelbrocks support this camshaft
By the way the hughes 1110 matches the edelbrock 5767 almost perfectly
If the Eddies will work I will go with this cam if not I will punt and go back with the compXE and stop pestering you guys(on this subject):thankyou:
Click to expand...

Beware of coil bind with any single springs with that much lift on LA heads. Usually you only have 1.62-1.65" installed height, which makes .500" lift and up really tough. 1.65"seat-.500"lift-.060" safety margin=1.09" bind minimum height. So you'd have less, like 1.07" theoretical.
 
Bighead440 said:
Beware of coil bind with any single springs with that much lift on LA heads. Usually you only have 1.62-1.65" installed height, which makes .500" lift and up really tough. 1.65"seat-.500"lift-.060" safety margin=1.09" bind minimum height. So you'd have less, like 1.07" theoretical.
Click to expand...
The camshaft directly below that Has a .470 Lift
Howards Cams Hydraulic Flat Tappet Camshafts 710991-08
how about that 1
 
scott657 said:
The camshaft directly below that Has a .470 Lift
Howards Cams Hydraulic Flat Tappet Camshafts 710991-08
how about that 1
Click to expand...

The .520" may clear, but never assume and always verify. It will be close, whereas the .470 will be certain. You can just use Comp #901-16 drop in springs with that. I have the 270S (224*.468: before lash) with those and zero issues, even at 6500+ in my 318 (328"). You may have more installed height with the RPM heads, so don't give up on the .520" Howards before you measure or have it done!
 
I like the 451 cam better
that last cam had a lot more duratin for a lot less lift
but since we know nothing about your project...
 
Here is the combo, those eddy heads and springs(5767) or (5825)
Stock 1976 360 Bottom end
Performer RPM Intake
Eddy 650 AVS2
electronic ignition with jegs box
Dougs 453s 2-1/2" dual exhaust
904, Stock converter( but could/will change)
Ford 8" rear 3.40 Posi
P225 70 15 tires 27.4 Diameter may go taller to reduce cruise rpm
My goal is to get the most out of the eddies in their present
configuration. the flow numbers seem to top out at about .5 lift
Small Block Head Flow Chart
I know I can run a comp or crane but I would like to take advantage of the heads without spending a fortune
 
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