FSTR-THANU

iTrader: (9)

Here are some pics of my lifter bores after bushing. No more low oil pressure for this solid roller!

Bushed Lifter Bores


Tom

<small>[ March 10, 2003, 09:54 PM: Message edited by: FSTR-THANU ]</small>

LOnSLO

iTrader: (15)

How much machining of the bores did you have to do? And where did you find the bushings?

CAMN HAWK

iTrader: (4)

how common of a problem is this with solid roller cams?

FSTR-THANU

iTrader: (9)

Diamond pistons did the machine work for me as a favor. They do not normally do this type of work. I have had oil pressure problems with my SR setup from day one. 5psi at idle and 25-30psi at wot. Hopefully my problems will be solved.

Tom

Camaroholic

iTrader: (1)

I know that Futral likes to do lifter bore bushings, but Thunder doesn't do them. However, I'm not sure what the highest lift cam that Thunder has done on a solid roller is.

Gets back to the post JoeK made a couple days ago about the solid roller oil pressure problem, with the lift & base circle of the cam causing the lifter to slide past the oil hole on the lifter bore, thereby causing the 'leak'.

Approx. what lift cam are you running? I'd assume it's larger than .65", no need to be real specific. Thunder's had no trouble with a .60" cam, but I'm just wondering ( <img border="0" alt="[evil]" title="" src="graemlins/gr_devil.gif" /> ) where a cam with something like .64" is going to fall for this low oil pressure phenomenon.

-Andrew

AP-Engineering

We can supply anyone with the lifter bore bushings. They are not that hard to install, most local machine shops should be able to do them.
As for the lift of the cam....it does not have anything to do with the reason that some have good pressure and other don't. Each lifter, generally, has what is called a wedding band around it. Basically a indent where the lifter gets it oil while on the base circle. On a solid roller the oil is shot straight threw the lifter and up the pushrod to the rocker. Pretty much free flowing design. With that being said you need to restrict the oil from putting that much volume threw the pushrod. On a hyd. roller the lifter does this for you by the way they work. Also with out the bushings installed, the oil galley hole is very large, say the size of your thumb. When we put the bushings in we restrict these oil galley holes to .040" to .060". By doing this it limits the amount of oil the lifter can see. Thus reducing the amount of engine oil flow, which in turn keeps the oil pressure at a good level. You can do this also by keeping the lifter bore to lifter clearance tight, .001" or less. There are also a few other ways that you could help this "bleeding" problem, but the bushings are a sure bet that will work all of the time. I hope this makes sense to you, I am having trouble putting it into words I think. Brain freeze!!!

Thanks,
Chris Gelineau
Diamond Pistons
877-552-2112 toll free

AP-Engineering

Toms engine has the crane lifters in it. They are one of the first ones crane did. The wedding band can be altered to help keep oil flow at a minimum. I am not sure if the new cranes are like that.

Camaroholic

iTrader: (1)

In that case, would it matter what design lifter you are using?

For example, the Crane 10510-16 - intended as a SR 'drop in' replacement for an OE Hydraulic Roller lifter, versus a standard CompCams SR lifter? Crane's web site states boldly that they do "NOT recommend the use of oil restrictors" - which is what this bushing is, is it not? I'm just very curious, that's all. <img border="0" title="" alt="[Smile]" src="gr_stretch.gif" />

Thanks,

Andrew

Jason99T/A

iTrader: (21)

Damn, that looks good. <img border="0" title="" alt="[Smile]" src="gr_stretch.gif" />

AP-Engineering

Jason, I talked to Paul and Jeff about geting you guy's some of our lifter bore bushings. Let me know if you guy's want to try them.

Thanks,
Chris

Jason99T/A

iTrader: (21)

That sounds great Chris! I know Paul will be in touch regarding that, especially for that C5R solid roller block we will be doing in the near future. <img border="0" title="" alt="[Big Grin]" src="gr_grin.gif" />