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So I’m upgrading some items while the motor is being redone.
One of them is an upgrade to a Boundary Engineering Billet oil pump gear. And my engine builder has some concerns.
So first things first, I’m from South Africa and I have a stroked and boosted DE.
I had a new DE oil pump fitted when we found some oil pressure issues.
Motor did around 1000km and the cam went for a ball. But that was an issue caused by the mech on assembly and the shop is paying for the rebuild.
Anyway, I have now opted for the Boundary gear. But when the shop decided to fit it, they found clearance issue out of the factory specs on the diameter of the outer gear ring. I’ll post up the photos :
Factory spec shows 0.0045 - 0.0102 Boundary gear is 0.2mm under the factory gear size The clearance is 0.012. 0.0018 over the factory spec
Now I’ve spoken to Boundary. And they say that the extra clearance is to allow for greater durability and will be slightly louder, but under stock circumstances. But will not have any issue with oil pressure.
I’ve now decided to put the DE pump aside and have bought a new Rev Up pump which I will swap the gears and fit the boundary gear.
Those who have used or fitted the boundary gear. Have you come across the same tolerance range I have? Or do you see an issue?
My builder is unsure with tolerances and is fairly cautious.
I havent used it but as soon as my block is out of the car I want to upgrade to either boundary or sucker punch motorsports ... so I dont have direct experience but consider the following...
Most people use the Rev-Up oil pump on DE builds and further I think it's best practice to use a new oil pump body for new pump gears.
I would think that the excessive clearance wouldnt be an issue. I'd factor in that you are measuring it cold and as it heats up it's going to expand in each direction (true for the outer gear and inner gear) and that clearance will decrease a small amount.
I havent used it but as soon as my block is out of the car I want to upgrade to either boundary or sucker punch motorsports ... so I dont have direct experience but consider the following...
Most people use the Rev-Up oil pump on DE builds and further I think it's best practice to use a new oil pump body for new pump gears.
I would think that the excessive clearance wouldnt be an issue. I'd factor in that you are measuring it cold and as it heats up it's going to expand in each direction (true for the outer gear and inner gear) and that clearance will decrease a small amount.
thanks for the reply man. Boundary did say that as well that once it gets heat into it, it would get more into spec.
Factory gear on the DE pump had a clearance of 0.006 (cold measurement).
I understand oil pressure won’t be an issue at higher RPM, just worried at idle and city driving that it doesn’t hold up the way it should. But maybe I’m just over thinking and worrying. Boundary did say that the gear will never fail.
Gallery gaskets have been done too, and the new rev up pump should arrive soon.
List on the car is fairly hefty. Brian Crower Stroker kit
JE Low Comp pistons (98.5mm 8.5:1)
Brian Crower stage 3 cams (272/272) (11,66lift)
ARP Throughout
OS Giken Triple plate Clutch
Darton Sleeves
Hitachi 1200cc injectors
GTM Stage 2 Twin Turbo Kit
Ferrea 1mm oversized Valve Set
19 inch Lenzo Wheels
D2 Suspension kit
HKS Exhaust system
ART Test pipes
External Wastgates with Screamers
Carbon Fibre Spoiler
Kinetix Velocity Intake Plenum
MaxxECU Race System
Koyorad Hyper V Core Radiator
Custom intercooler with piping
DW3000 Fuel pressure Regulator
Full fuel return system (ethanol ready)
Bosch 540lph in tank fuel pump
Flex fuel system
FTF in line fuel filter
Full respray - Porsche Grey - 7A1
Nismo V3 front bumper
R50 pathfinder cooling mod
Before After After After 😎
Last edited by Drag0nSban3; Jan 9, 2021 at 07:07 PM.
I dont know anyone that has had long term success with a sleeved block ... I'm sure theyre out there but I dont see them. With that being said I think it's based on the machine shop and how well they machine the block and install the sleeves.
Pulling for a kickass build for ya though and wish nothing but the utmost success!
No, I personally dont think a sleeved block is worth it ... I think if you're going to spend that much money to make +/-800 to 1200hp than you should look at a different platform. With all that being said I completely respect and admire that you're taking it on and I wish you nothing but sucess and I'll be your biggest cheerleader...
I'm very interested to see your results - so keep us updated!
When I bought the car, the previous owner had already had the sleeves, cams and turbo kit fitted. Looked as though whoever fitted the pistons and rings, didn’t do it properly. Car ran but smoked heavy. Stripped it and found the rings were busted.
anyway, we stripped everything down to nothing. Cleaned, replaced and rebuilt the entire unit with little upgrades where I felt it was needed.
cam snapped before due to engine builder allowing apprentice to put together. So the shop is honoring a warranty and covering the rebuild cost.
and they seem to be taking full detail into getting it back together. I’m pleased with their detail so far.
motor ran 3400km before the cam went. It was strong. 370wkw/620nm.
I’ll post up once all is running etc. follow my IG @thatgreyz
THat's a great story! Probably the rings werent bed'd correctly - happy your rescuing her! Start a build thread (maybe keep this thread going with all your progress).
Very cool that the shop is standing behind the work! good for them!
I am actually going to assemble a 3.8liter sleeved block for a buddy and the block was formally Sam35Z I think? The machine work was done in 2019 / 2020 and we're gonna assemble here in a month or so! I'm excited for it.
For sure on the follow - looks like a kickass build! I'm Unknown_Performance -
Front timing cover still needs to go on. But that’s another post. Some clean up happened, then a better look happened 😂 New RevUp pump is on, with the Boundary Engineering billet gear.
So now the Brian Crower Stage 3 cams are in, torqued down and clearances checked properly.
Top tensioners are in, inner timing cover going on next. Then the timing kit can get fitted.
No short cuts.... new everything!!!
Inner timing cover all cleaned up, gallery gaskets replaced with new items. And the hardware replaced for proper torque applications.
R50 mod still to be completed, clamps need to be fitted, thermostat to be fitted on and completed. Timing covers, chain and guide kit to go in.
Complete silicone hose kit also going in. Already have a Koyorad Hyper V Core radiator that went in.
Considering a set of SPAL fans to move more CFM. But will look into that once we see where the temps are at with the car running. Just not sure which SPAL units to look at. Possibly the 13”. Two of them.
Boundary Engineering Oil pump gear
And the cams are in, timed, and torqued. 
