Dart shp block
 

Any of you that Plan to use a Dart shp block be aware there are no holes in the front of the block to allow the oil to drain back down to the pan. This is a real problem in a drag race car. I just finished getting my new motor out today and I am heading back to Parsons and Myers for them to disassemble the motor and put drain back holes in the front. The quality of the block seems excellent, I just don't know why Dart didn't do this to start with. Their little M block has them.

Re: Dart shp block
 

Greg, are you talking about those two big holes behind the timing cover? I've never put those in. The Dart blocks I've used have the returns like a big block, over the camshaft. I'm not sure those two behind the timing cover even do anything, except maybe after you start to slow down. I have not done one for Stock, but I have done some for regular bracket cars. I have not had oil return problems.

Re: Dart shp block
 

Glad to hear you say that, Alan,,, had me nervous there for a minute. We're taking a brand new SHP based 406 out for the first time this weekend. We haven't had any oiling issues so far, through a dozen dyno pulls and a little running time in the driveway, after installing it.
We'll keep an eye on it and our fingers crossed.
Danny Durham

Re: Dart shp block
 

So Greg did you seal the lifter valley and that's why you need the front holes?

Although not necessarily relevant, none of the Dart small blocks have the thermostat bypass drilled into the block, so you need to at least drill a couple of 1/8" holes in the thermostat unless you're just running a restrictor. (or nothing)

Re: Dart shp block
 

I'm guessing here but the problem is in the shutdown. Oil pumped to the lifter valley needs to get to the pan some way. On clean neutral systems u won't notice it but with some pans you will loose pressure quickly on decel with the motor still running. How that oil keeps the pick up covered on neg g forces still baffles me. I noticed this when belt drives first became popular as the belt drive cover blocks a little over half of the dr. side hole in the front of the lifter valley and on a big pan would drop pressure under decel. For years I lowered the front holes in factory blocks that Greg is talking about to allow any oil to leave the lifter valley on sbc's because stand offs in the valley were common to keep oil off the crank. I always tried to get any upper oil back to the pan as efficiently as possible by radiusing or lowering any return holes as I'm sure Alan does. Just to keep it off the crank. I know everyone says that the chev engines have great oiling systems from the factory and I agree but I have found some problems that needed to be addressed to make everything just right with different pans and driving practices. Greg, I slot new holes as low to the valley as possible on those blocks and probably bigger than needed. They seem to work better wider than taller.
Its a trick to make sure u have enough upper lubrication but only enough to make parts live. Some stuff works on some racecars but dosen't seem to effect others either way.

Re: Dart shp block
 

Greg,
Check out my link I have gotten some oil restrictors made for these blocks. Have them for sale on ebay here is the link

http://www.ebay.com/itm/300703558232...84.m1555.l2649

Re: Dart shp block
 

I have machined and sold probably 150 of the SHP blocks and so far no issues with oil returns, The block should have an oil return in the middle of the lifter galley all the way to the front, I feel you don't need to drill any required holes in the front of the block as no one else is having any issues that I know of..

If your running roller lifters don't not restrict them as most lifters are restrctied to begin with!!

If your lifter bore clearance is .0014 to .0019 you should be fine.

Re: Dart shp block
 

The slots in the lifter valley were sealed except for part of the back one. The problem is that with the slots sealed and the webbing cast into the block to make the cam tunnel stronger there was no way to get the oil back to the pan from the front of the motor. Some holes drilled in strategic places should fix this. The webbing was acting like dams in the lifter valley.

Re: Dart shp block
 

I suppose you're trying to keep oil from going down past the cam onto the crank and rods. Not sure there is any gain there, there are tons of fast big blocks with the lifter valley drains wide open.