I have searched around long and hard... but I haven't found too much info on anyone using the Boundary oil pump gears in a stock oil pump housing and if they had changed the oil relief spring pressure. Mostly just the full Boundary pump upgrade.

Just curious if anyone is still running the gears only upgrade in say a VVT/MSM BP6D oil pump or if someone has upgraded the relief pressure with success.

I am still on the fence with this upgrade and since living in Canada where getting one of these is almost double the price I am trying to squeeze it into the budget for my build.

I see a lot of people with the full upgrade pumps running 1 extra shim for pressure. Do people do this with stock pumps or I believe I did read somewhere about the 323 GTX relief spring being higher.

Car is a 93 NA and is a street/track day toy that does get beat on with an MSM engine being swapped in (bottom end will be: CP stock size pistons, M-tuned rods, ACL std race bearings, Full ARP studs and Mazda gaskets)

Thanks

 

I know one I installed, street pump, had a washer below the spring.

 

Almost deciding just to do the street pump with gears as its a little bit more money but much easier.

Assuming it only comes in the thinner version vs the thicker VVT version that came in the MSM? or is there a street VVT (BP6D housing) option as well?

 

Also after some research Ive found that the ARP main studs aren't a straight bolt in affair.

They require clearancing the MBSP(non issue) and possibly a line hone/bore?

If the line hone is required I may rethink the ARP mains and just use stockers

 

We have not seen a line hone required with ARP mains.

 

Oh good, cause I didn't on my recent and first arp build.

For the mbsp, you just need to drill 8 1/2" holes above the two front sets, and two rear sets of studs. Middle set doesn't interfere. Measuring and drilling in the correct location is the hardest part. Mine took Lots of test fitting and dremeling after I miss measured. Lots of cleaning too, as you want it free of shavings for test fitting.

 

Okay perfect. I guess its just one of those recommend type of things for the line bore/hone

and yes I did read up on the drilling the MBSP or cutting the studs. 1/2" seems easy enough with measuring. thanks.

 

There are tabs that fold down in the inner 4 holes, drill right next to those, approx.

Ends are easy, just 2 cuts to remove the corner.

 

Awesome thanks. I'm definitely keeping this thread for when I do cut them.

I'm also assuming you used the 65 ft/lb w/ lube spec for the mains when you did yours?

 

Arp says 60ft/lbs