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I talked to a tech at Howard’s cams. They set me up with a matching spring / retainer set for my cam and spring locators & seals. Hopefully it will work well. I’ll keep post updated after repairs. Thanks for everyone’s advice it was very helpful. Especially about the spring locators. 👍
The pockets are probably 1.46 inches. the larger the diameter of the spring the cooler it will run and the longer they keep their listed pressures. Tell Howards that you would like something like 130 -135# on the seat. But you need to figure out the present installed height when you talk to them. This isn't as exacting as a micrometer, but it is very close.
The galling on the taller ARP studs is from the .700 + lift cam with 240# closed pressure and over 700# open. Dart race ported 227cc heads with 2.10 in and 1.625 Ex. My vette heads
I must have gotten lucky with my used dart IE180s since while I replaced the springs with the correct pressure springs recommended by lunati for my cam, I used all the existing hardware from the old springs which looked like the ones pictured above only the larger diameter ones that filled out the machined seat area.
Last edited by augiedoggy; Nov 9, 2020 at 03:30 PM.
For a Hydraulic Roller I would run a 1.460 OD spring. This is the "go to" spring size for Hyd Roller.......
You are looking for 130 on the seat and 360 or so over the nose.
I find it kinda hard to believe that a Howard's tech would spec 1.26 diameter springs for Hyd. Roller.......
Generally smaller springs will have an I.D. locator and larger ones will have a spring cup.
Not on a Dart Iron Eagle head....cut for 1.55 cups.
Jebby
I couldn't find the exact size online, but the base model is sent with 1.25 springs, no cups, and .520 max lift. The OP said .510 cam lift. It just crushed the dampener.
I couldn't find the exact size online, but the base model is sent with 1.25 springs, no cups, and .520 max lift. The OP said .510 cam lift. It just crushed the dampener.
Yep....but all Dart heads are cut to 1.55 on Small Blocks and 1.625 on Big Blocks....so going to a 1.437 Hyd Roller spring will be easy....in fact, just order a Dart 1.437 assembly kit. Dart will sell it to you without valves and guide plates....just call them: 248-362-1188
Jebby
Last edited by Jebbysan; Nov 10, 2020 at 12:15 PM.
Would it be ok to run a 1.460 dual valve spring as long as the seat pressure & open pressure was around 130 & 380. ?
Yep....I think the easiest thing for you to do is to call Dart. They have bags of these spring, lock, retainer, seal kits on the shelf.....they are for their “shelf” heads.
Eliminate a sourcing headache.....buy them and install them.
You can run springs direct on an Iron Head with no cup or locator but you will need them for a larger spring to hold them still.
Update: I called Howard’s cams and Dart machine (thanks Jeb for the ph. No. ). Dart said to run Howard’s recommendation for spring. Dart tech said don’t get hung up on spring día. Just run a locator and it would be fine. So that’s what I did. Howard’s 1.25 spring kit and seals. 130 seat press. 380 open press at 1.808 installed height. And a spring locator. Everything fit perfectly. Oil change. Cut open the oil filter and no metal. Up and running great. Thanks for everyone’s help. A few pics of the install. I think the old springs may have had a seat press of 90lbs. They were really weak compared to the new ones.
Last edited by speedreed8; Nov 24, 2020 at 09:54 AM.
