Experts needed-Shims and/or 3G Lifters?

[JwpRider]

Ok, did some research and seems to be some 'opinions' on this question. I bought a set of Delta Regrinds (272/272) and they did not come with shims. Some research indicates that if you use the 3G lifters, they have enough 'range of motion' that shims are not required. Others note to use shims with regrinds regardless, as to not chance (or strain) your lifters. (aka HLA). Several concerns are:

• I don't know what shims (what size washer-thickness) to use - if at all.
• If I don't use shims, will my redline be reduced due to the increase range the 3G lifter will need to travel? (or is the redline more related to your valve springs to avoid valve float)
• Should I use both?
• Finally, what would you consider the 'redline' with stock 2G springs, and 272's before considering an upgraded spring?

I plan to run a HX40, SMIM, etc...looking for 600HP. I realize there are many other concerns to reach this goal...but for now I am looking for the DSM Experts to weigh in on this 'shim' question.

Thanks to all!!

 

[bryanwheat]

I would contact delta and see what they have to say.

 

[RadDsm]

Use #10 washers as shims, .030" thick.

 

[delta448]

I don't know what shims (what size washer-thickness) to use - if at all.

I'm not 100% on this, but I would imagine that it might depend on the amount the base circle of the lobe has been reduced when the cam was reground.
You probably don't need shims, and in fact, I'd be concerned that shims would cause issues.

If I don't use shims, will my redline be reduced due to the increase range the 3G lifter will need to travel? (or is the redline more related to your valve springs to avoid valve float)

The HLA should not really be moving. Once it fills with oil and takes up all the slack to create zero valve lash, it should not move much if at all. Deciding your redline depends on many things; the ability of the valve spring to control the closing motion, rod bolt strength, rotating assembly mass, usable powerband, your willingness to risk failure, the max speed at which your trans will allow shifting, etc. etc.

Should I use both?

Both what? The 3G HLAs and shims? Use the 3G lifters if you want. Use shims if the HLAs cannot maintain zero lash on the smaller base circle cam.

Finally, what would you consider the 'redline' with stock 2G springs, and 272's before considering an upgraded spring?

If the springs are measured within factory spec for pressure, then the recommended redline would be the same as it is for the cam the regrind is based off of. Some cams are not recommended to be used with stock springs at all due to their aggressive ramp rates. I stress this, test your valve springs if you don't plan on changing them. I've seen OEM springs that have become VERY weak over their lifetime.

 

[e85_4g63]

Same thing happened to me. Call Delta and talk to Ken (he knows his stuff). You can use stainless steel washers that are 1mm thick. He offered to send me some, since my cams also didn't have the "shims" with them. I ended up just going to my local hardware store and buying 16 1mm thick s/s washers and never had a problem. That was in 2009. Motor is still fine to this day... Hope this helps. I couldn't afford to wait for Ken to ship me the shims, as they are in Washington and I'm across the country in PA.

 

[JwpRider]

You probably don't need shims, and in fact, I'd be concerned that shims would cause issues.

The HLA should not really be moving. Once it fills with oil and takes up all the slack to create zero valve lash, ... Use shims if the HLAs cannot maintain zero lash on the smaller base circle cam.

Thanks everyone for your inputs! But how do you check that the HLA maintains zero lash? Is it as simple as checking clearence between your rocker and HLA once it is filled with oil? What is this clearence value?

If your clearence is within spec, then I do not have to upgrade to 3G's or install shims? just wanted to clearify...

 

[BogusSVO]

In a perfect world, you want the HLAs to be in the center third of there working range ( most lifters/HLAs have a wornking range of .060-.080)

With a reground cam, the base circle is smaller than stock, so measure a stock cam base circle then subtract the reground cams base circle and that will give you the thickness of the shim you need

When the HLA pumps up/fills with oil there will be ZERO clearance between the wheel of the follower and the heel of the cam.

Did you test your stock valve springs?

http://www.dsmtuners.com/forums/newbie-forum/341287-how-test-valve-springs.html

http://www.dsmtuners.com/forums/newbie-forum/341209-4g63t-valve-spring-info.html

 

[TJCTalon]

I will be running shims with my 3g lifters and DKS 272 grinds. Delta told me I needed the shims. There must be a reason they give them when you buy the cams.

 

[JwpRider]

With a reground cam, the base circle is smaller than stock, so measure a stock cam base circle then subtract the reground cams base circle and that will give you the thickness of the shim you need

In other words...even if I upgraded the HLA's to 3G's...I would still need to use shims? (This is the debate...some believe 'no'...others 'yes'!) Do you know of a link which describes the process of measuring the cam base circle? I can do the math. I can get the 3G's and shims if that is what's required, I just don't want to create a problem.
Thanks to all!

 

[BogusSVO]

Since the 3g HLAs are a stock HLA, I feel they would be max'ed out on the working range of them with a reground cam.

I do not know of a link to show how to measure base circle of a cam. But it is simple.

Use a mic or venier caliper, and measure the sides of the lobe, this will be the smallest measurement of the lobe.