Advice on valve spring height, load on a L98 383

Hi ther my first post.
Building a SBC 383 to slap in a C4 1985.
The engine i all new parts. not yet assembled
block GM-10066034
Edelbrock 5089 64cc heads, comp cams beehive springs (26918) Retainers, locks and seats.
PRW 1.6 Pro Series Billet Aluminum and Stud Girdles.
Comp Cams Xtreme Fuel Injection; XFI™ 260XFI H13 , High Energy Hydraulic Lifters and Magnum Pushrods.
Eagle B13054E 030 rotary assembly with KB 18cc hypopistons and SIR rods and cast crank.
King full bearing set and exstra Speed Pro set.
Canton Racing Circle Track Wet Sump Oil Pans 11-120M
PRW water pump.
Melling M155HV oilpump
Hedman ELITE Headers; 1-5/8" 68448 + 3" to 2.5" unknown brand muffler system with x pipe
ARP Fastener on rods, heads, hedders, etc
90000 Professional Products Harmonic balancer

have certainly forgotten something

The intake is a portet OEM used base with TPIS ported runner tubes and plenum, 2x58 throttle-body
fordracing 24# injectors.
Davis Unified Ignition 12600BK Distributor with MSD Street Fire Ignition Control.

and micro squirt diy pnp to control the engine with innovate motorsports LM-2 o2 controller.

and know to my questions.

The hight on install spring hight is 1.750 i was suppose to be 1.8 but i think the retainer combination made i sow.
the spring load at 1.750 i 160 lbs and 1.300 is 315 lbs is this to much ? on the seat with a flat tap cam
is it possible to masking down the seat 0.05? can the Edelbrock 5089 head take that?
Well the camshaft is bought.
Just Ok.
I like Crower and Isky Cams.
Grumpy has his own choices.

Seat load is too high for a hydraulic flat tappet cam.
Lobes will be wiped off fast on that CC 260 cam.
105-110 lbs on the seat spring pressure be better.
115-120lbs max.

110 lbs be ideal.
if the current valve spring retainer, valve locks and valve spring installed compressed valve spring height is 1.750 swapping to a .050 offset set of valve locks,
allows the valve retainer to lock .050 higher on the valve stem, thus the 1.800 installed valve spring height and a slightly lower load rate
measure the valve diameter , you have single grove 7 degree valve locks
you can increase the distance between the spring seat and retainer with a simple swap to plus .050 7 degree valve keeper locks like these,
of the proper diameter
Locks, Keepers, Hardened 11/32" X 7 Degree, .050" Up Locks, Raises Retainer Higher
plus .050 7 degree valve retainer locks




GrumpyThe Grumpy Grease MonkeyStaff Member

you might want to buy a few of these
while they are on sale at a reduced price

heres a bit of useful related push rod length info (POSTED HERE) youll want to select the correct set or SETS for your shop

Big Block Chevy, Standard Length Big Block Intake 3/8" / .080" 8.275"
295-7941-8 Big Block Chevy, Standard Length Big Block Exhaust 3/8" / .080" 9.250"
295-7969-8 Big Block Chevy, Standard Big Block +.100" Long Intake 3/8" / .080" 8.375"
295-7979-8 Big Block Chevy, Standard Big Block +.100" Long Exhaust 3/8" / .080" 9.350"
295-7951-8 Big Block Chevy, Standard Length Big Block Tall Deck Intake 3/8" / .080" 8.675"
295-7961-8 Big Block Chevy, Standard Length Big Block Tall Deck Exhaust 3/8" / .080" 9.650"
295-7800 V8 396-454 Retro Fit Pushrod Set, Intake & Exhaust, 1965-Present
3/8" / .080"
3/8" / .080" 7.725 Int.
8.675 Exh
295-7913-16 Small Block Chevy, Standard Length Small Block Chevy 3/8" / .080" 7.800"
295-7984-16 Small Block Chevy, +.100" Long 3/8" / .080" 7.900"
295-7934-16 Big Block Ford, Standard Length Ford `72-'78 429-460 3/8" / .080" 8.550"
295-7951-16 Big Block Ford, Standard Length Ford `69-'71 429-460 3/8" / .080" 8.675"
295-7582-16 Oldsmobile, Std Length 455 5/16" 9.550"

  • Reduced
    Part Number: 70463-2
    Checking Pushrods

    Checking Pushrods 7.975 +-.250 (Pair)
    Learn More
    Regular Price: $28.13

    Your Price: $13.99

  • Reduced
    Part Number: 70461-2
    Checking Pushrods

    Checking Pushrods 7.150 +-.250 (Pair)
    Learn More
    Regular Price: $28.13

    Your Price: $13.99

  • Reduced
    Part Number: 70465T
    Checking Pushrods

    Checking Pushrod Kit (1) 8.150 +-.250 (1) 9.150 +-.250
    Learn More
    Regular Price: $28.13

    Your Price: $13.99

Proform Pushrod Length Checkers 66789 SBC 3/8" rocker studs

Proform Pushrod Length Checkers 66790 SBC 7/16" rocker studs

Proform Pushrod Length Checkers 66806 BBC 7/16" rocker studs


The following recommendations are from Erson Cams. If you have questions, you can reach their tech department at 800-641-7920.

Hydraulic Flat Tappet Camshaft: 110 lbs Seat pressure/250-280 lbs open pressure

Solid Flat Tappet Camshaft: 130 lbs Seat Pressure/300-325 lbs open pressure

Hydraulic Roller Camshaft: 130-140 lbs Seat Pressure/300- 355 lbs open pressure

Solid Roller Camshaft: (Minimum Safe Pressures DEPEND ON SEVERAL FACTORS)

Up to .600˝ valve lift: 200-235 lbs Seat Pressure/600 lbs open pressure

Over .600˝ valve lift: 250-280 lbs Seat pressure /100 lbs pressure for every .100˝ of valve lift

open the link to look at valve spring options
(866) 799-9417
heres their ph#
Toll Free (866) 799-9417
I always just order the springs retainers valve locks and spring seats as a package deal (NOT CHEAP BUT EVERYTHING WORKS AND FITS) then you just need shims under the valve spring seats occasionally to get the correct installed height Springs/Store/13 ... of-16.aspx

related threads
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If you are not willing to change valve springs to something a little less stiff, then the +.050" locks is the way to go.
That is unless they cause interference issues between the underside of the rocker arm and edge of the valve spring retainer.
Since you have to disassemble the setup anyways, pick up a cheap set of weak(er) valve springs to use for the camshaft break-in.
Then after a successful BI, swap to your running beehive springs.
Thank you for all suggestions. the most annoying thing i that i wrote mail to comp cams explaining my setup in detail and asked which valve springs, seats, retainers, locks they recommended.
"Parts list you need: 26918-16/787-16/4709-16/601-16 Dallas Griffin Technical Sales & Support"

And i even asked them after bying :have beehive 26918 125lbs @ 1.800 open 311 lbs 1.300 is this to much under break-in the new engine and flat tape camshaft? Could it be better to use beehive 26915 under break-in first 30 min max rpm 2500? 105 @ 1.800 open 262 lbs? Or is ther another better solution? Thanks in advance "Hey,That pressure will be just fine.Thanks On Mon, Dec 18, 2017 at 11:40 AM, Ricky Kennamore"

was just 3 weeks vacation in Orlando, bought with me a valve spring micrometer and other tools. the return home and measured the height of spring on the heads with Retainers and Spring Locators Cups who ho 1.755"
Then i bought å scales and some MacGyver drill press, to measure the springs @ 1.750 1.800 and 1.850. of course was the spring pressure was higher then indication inn compcams catalog.

I bought the valve springs as an upgrade after reading sow much fuzz on the Edelbroc 5767 springs.

If i use the edelbrock springs under brake-inn the install the comp cams beehive with +0.05 locks Could this be a solution?

if not COMP Cams Engine Valve Spring Seat Cutter 4735; Carbide 1.580" and arbor to machinin down the seat ?

I have also forgotten to say that I live in Norway, If you cant do it your self the bill will kill you.
I think youll be ok if you just use the .050 valve locks, that seat the retainer .050 higher and compress the valve spring a bit less,that should reduce the seat pressure,
and yes you would be better off with slightly lower seat load rate valve springs,
but I've found that its not all that critical as long as your cam lobes are constantly bathed in oil flow and if your coating both the sliding contact surfaces between the lobes and lifters liberally in moly.
(at the potential slightly lower seat loads your looking at with the installed height at the full 1.8" installed height, with the new valve locks)
you should be using the correct installed height and carefully verifying rocker geometry and push-rod your far less likely to get into clearance or binding issues.
I would not machine the heads, as that will weaken the heads, maybe not much but still its not a great option.
lube the base of the lifters and cam lobes with moly paste lube
The Moly platelets that make up the protective layers on your engine surfaces slide across one another very easily. Instead of metal rubbing against metal, you have Moly platelets moving across one another protecting and lubricating the metal engine parts.


MOLY adds a great deal of lubrication to sliding metal surfaces , as it embeds in the micro fissures in the metallic surface's

if you were likely to be building and breaking in several engines Id suggest
purchase of lower 1.3:1 rockers for those cams break-in procedures.
this of course would not change the seat loads but it would significantly reduce the over the cam lobe nose pressure loads, and its the high nose loads and lack of lube flow,that tend to initiate rapid wear first.
I usually use 6-7 quarts of oil and 1 quart of marvel mystery oil added in my oil pan 11 quart oil pan and oil cooler system capacity
10W30 Valvoline VR1 Conventional Racing Oil
10W30 Valvoline NSL
10w30 Castrol GTX conventional,
10w30 mobile 1
10w30 KENDAL racing oil

and heres a good break in additive for flat tappet lifter cams


the better quality hydraulic and solid flat tappet lifters have hardened bases


open the link to look at valve spring options
(866) 799-9417
heres their ph#
Toll Free (866) 799-9417
I always just order the springs retainers valve locks and spring seats as a package deal (NOT CHEAP BUT EVERYTHING WORKS AND FITS) then you just need shims under the valve spring seats occasionally to get the correct installed height


If the valve springs are to be removed with the heads still on the car,
the last thing you want is too remove a valve spring and have the valve to drop into the cylinder,
if you use air the crank tends to want to spin the crank to BDC, youll want to verify TDC ,
and make sure the flywheels temporarily prevented from turning from that the TDC position,
Ive used both methods both work,you can put 6 ft of rope in the cylinder while its in BDC then turn it to TDC, Ive used both with zero issues,
If you use the compressor youll want to keep it at 120 psi and constantly feeding pressurized air to keep the valves held in place,
and theres a small chance the compressor pushes enough moisture to allow water to accumulate in the cylinders,
so be sure you spin the engine with the starter with the spark plugs removed several times before you re-install plugs.
if you use the rope, theres a very low chance that the rope will tangle and form a knot that makes removal difficult,
in either case be sure the pistons locked at tdc,
before removing the valve springs, on each cylinder. Springs/Store/13
read ....don,t ignore the links
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Here is another curve ball for you. I found this on Summit Racing while looking up your heads.

What is the installed spring height and seat pressure? Also, the spring rate? I'm trying to understand why a 1.46" spring installed with safe lift up to .550" can handle only 5500 RPM.

Asked by MICHAEL on May 15, 2018

To truly answer your question regarding valve springs, it seems you wonder why it only rev's up to 5500 rpm, it is because the valve seats are powdered metal, not ductile iron valve seats. The powdered metal valve seats are harder and the valves have a tendency to bounce off the seats, installed spring height is 1.800" with 120 lbs. on seat, with 310 lbs. open at .550" lift. Thank You for your question here today...

Edelbrock Answer - May 15, 2018

If the seats have a tendency to make the valves bounce, I'd be more concerned about using these heads with aggressive flat tappet cams (such as CompCams Xtreme Energy) that have a reputation for slamming valves shut than I would about using a mild roller, especially GM rollers which tend to set valves down easily.

MICHAEL from TX answered on May 18, 2018
Grumpy has A Favorite Crane Cam grind to use in GM Tpi Corvette engines.
I would use it myself in place of the Comp Cams.
Should hand lap the valves in and then be able to see actual seat margin width and on each valve face .
I would want .075-.080" intake side.
.085. -.100" on exhaust.
Street engine for long life.
Your Edelbrock 5089 heads say designed for use with hydraulic flat tappet camshafts ONLY less than .550 in. lift. Requires use of hardened pushrods.
The valve and seat combination, used in these heads, is not recommended for use with a hydraulic or mechanical roller camshaft.

If I were in your shoes, break your cam in with your heads set up the way they came from Edelbrock. Then switch over to the Comp Cams beehive setup.
But I would do the beehive setup before you install the heads on the block. Write EVERYTHING down.
Then when you switch over, all the measuring has been already done and you just have to swap the parts.
Buy the +.050" locks to set your beehives at 1.800". You don't need to use the stud girdles during break-in.
After reading your post, now I have to do some research on my Edelbrock Performer RPM 6073 heads on my 302 Chevy that revs easily to 8000 rpm with a solid flat tappet camshaft. I hope mine don't have the PM seats.
Springs will always test higher pressure when new. Usually the published specs are for after they are run in - they relax some.
Definitely switch over to the CC beehive setup for running. If your Edelbrock springs look anything like mine did, then break-in is all I would ever use them for. They are cut crooked and look like they used a sawzall to do the cutting.
After reading your post, now I have to do some research on my Edelbrock Performer RPM 6073 heads on my 302 Chevy that revs easily to 8000 rpm with a solid flat tappet camshaft. I hope mine don't have the PM seats.

So after a couple of hours researching and talking to Summit Racing, Edelbrock E-Street heads use powdered metal valve seats and are recommended for hydraulic flat tappet camshafts ONLY.
Performer RPM heads use ductile iron valve seats and can be use with hydraulic & solid FT and roller camshafts. They do not specifically mention solid roller, though.

Grumpy, I have these Crower "camsaver groove" lifters from Crower.
I will share that the groove that they grind as you show above measures .085" wide x .003" deep.
Oki doki crower VALVE LOCKS - 7 DEGREE +.050 on the way.
and now on the hunt for engine oil.
had to laugh, you have better selection of oils at walmart the i have in the lokal part store here in the country.