406 sbc SHP little oil to top end

[Boz-Race Engines]

hi guys, really need some help on this one, Dart SHP block, sbc 406 cubes, hyd roller, LS 7 lifters, tried another brand of lifters no different. very front rockers getting plenty of oil then really drops off to almost nothing at rear, valvetrain is very noisy. all gallery plugs are in, double checked them, no plugs are drilled etc, no restrictors fitted, o rings on dizzy, good oil pressure at guage port, full lifter oil band exposed to oil gallery on base circle, no blockages that we can see anywhere. 20w/50 oil, im pulling my hair out, any ideas ? thanks

[Roundybout]

My first thought after that description, if it's getting good pressure at the gauge and showing some at the front would be a blockage or possibly a cam bearing with excessive clearance.

[PRH]

Isn’t there a way to access the oil gallery for a gauge reading at the front of those blocks?

I’ve only looked at the oil schematic for one of those blocks once.
There are some plugs that need to be installed, at one end or the other, depending on which end of the block you’re feeding the system from.
Are you sure you have that correct?

(Or am I thinking of the Little M block?)

[PRH]

I can add one more tidbit of info that I have come across, not with the SHP blocks, or even hyd roller lifters....... but it’s a situation that “could” occur with any type of lifter.

In our case we saw a similar problem with lifter/pushrod oiling with a particular type of solid lifter.
These lifters had the lower edge of the oil band sitting higher than a “normal” lifter, and when the lifter was near the very top of the lobe, the band was no longer exposed to the gallery, and effectively shuts off the oil supply from that point forward.
Since all the lifters do it at different times, it’s like there is always at least one or two that are high enough to block the flow, and very little oil gets to the lifters at the front of the block.

On the first one we encountered like this....... it would take about 90 seconds on a cold start before any oil was seen up top, which was the rear most lifter/pushrod.
Even after 2.5 minutes, several near the front were still running dry.

If you pull out the rear gallery plugs and look inside, you can see the rearmost lifters.
If the oil band disappears up into the lifter bore at high lifts...... you’ll have the kind of problem you’re experiencing.

[cpmotors]

Did you use the Dart 3 hole cam bearing or the GMP-8?

[tenxal]

Are the lifter bores bushed?

[GARY C]

I can add one more tidbit of info that I have come across, not with the SHP blocks, or even hyd roller lifters....... but it’s a situation that “could” occur with any type of lifter.

In our case we saw a similar problem with lifter/pushrod oiling with a particular type of solid lifter.
These lifters had the lower edge of the oil band sitting higher than a “normal” lifter, and when the lifter was near the very top of the lobe, the band was no longer exposed to the gallery, and effectively shuts off the oil supply from that point forward.
Since all the lifters do it at different times, it’s like there is always at least one or two that are high enough to block the flow, and very little oil gets to the lifters at the front of the block.

On the first one we encountered like this....... it would take about 90 seconds on a cold start before any oil was seen up top, which was the rear most lifter.
Even after 2.5 minutes, several near the front were still running dry.

If you pull out the rear gallery plugs and look inside, you can see the rearmost lifters.
If the oil band disappears up into the lifter bore at high lifts...... you’ll have the kind of problem you’re experiencing.

I have also read where a small base circle cam can drop them below the passage. Some new lifters are chamfered at the oil band for this reason.

[af2]

, o rings on dizzy,

Get rid of the O rings

[af2]

, o rings on dizzy,

Get rid of the O rings

And 10/30 oil

[MadBill]

, o rings on dizzy,

Get rid of the O rings

What trouble do they cause?

[af2]

Dart and others with priority oiling say not to use the sealing O-ring on the distributor. Also the distributor band must be in-line with the galley.

[Boz-Race Engines]

oil band height is ok on lifters, cannot see why you would take o rings off dizzy that would only cause more bleed off in the lifter gallery, how could a tighter lifter bore clearance slow oil to top? it goes through oil hole in lifter oil band then through pushrod. has 3 hole dart cam bearings

[Boz-Race Engines]

might have to pull it back down and check all oil galleries etc

[tenxal]

No reply to the question on whether the lifter bores are bushed.....

Anyway.... as the lifter comes up, the axle hole can get close enough to the longitudinal oil hole in the lifter bore to cause internal leakage that gets progressively worse down the line.

[GOSFAST]

I can add one more tidbit of info that I have come across, not with the SHP blocks, or even hyd roller lifters....... but it’s a situation that “could” occur with any type of lifter.

In our case we saw a similar problem with lifter/pushrod oiling with a particular type of solid lifter.
These lifters had the lower edge of the oil band sitting higher than a “normal” lifter, and when the lifter was near the very top of the lobe, the band was no longer exposed to the gallery, and effectively shuts off the oil supply from that point forward.
Since all the lifters do it at different times, it’s like there is always at least one or two that are high enough to block the flow, and very little oil gets to the lifters at the front of the block.

On the first one we encountered like this....... it would take about 90 seconds on a cold start before any oil was seen up top, which was the rear most lifter/pushrod.
Even after 2.5 minutes, several near the front were still running dry.

If you pull out the rear gallery plugs and look inside, you can see the rearmost lifters.
If the oil band disappears up into the lifter bore at high lifts...... you’ll have the kind of problem you’re experiencing.

Pay close attention to the input here in this specific post, it is "spot-on". Usually it's seen when priming the unit and various lifters don't get oiled correctly. During the priming period it should NOT be necessary to turn the crank over to get oil to ALL 16 lifters or rockers. If you need to "spin" it for upstairs oiling you have a potential issue!

We come to realize this a few years back and since then began modifying ALL the blocks we work with, whether it is necessary or not. Various lifter brands go fine, others not so! We do them ALL to eliminate the issue.

During the "mock-up" period if you lay the cam in place along with a front pair of lifters you can "sight" the oil band through the front galley (oil plug out obviously) and watch the lifter cycle by turning the cam by hand. It'll tell you the whole story from this point forward!

Thanks, Gary in N.Y.

P.S. Here's a shot of the lifter bore modification we now do. We do both the SB's and BB's, with this mod it makes no difference the brand of lifters you choose?

Lifter Bore Modification.JPG