1/2 way done with my build and looking for some more insight

supramic

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Feb 4, 2006
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magnolia DE.
ok im almost done with my motor right now im just working on the bottom end,
i have alot of questions that i came up with through searching the forums

- what should i do shim the oul pump or change the spring, im leaning toward geting a heavier spring from a 350 pump but i dont know whick pump to get it from
-where can i get an after market oil pan??

- has any one used a ct20 dual wastgate exaust housing with a ct26 compresor housing ??????? and would it be worth it, im looking for a quick spool
- doesn't cliping the exaust blades create more lag

some one help i have to many questions lol
 

IJ.

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Mar 30, 2005
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Mic: If you have a way of accuratly measuring the free length and wire diameter in the 2 springs you could calculate the rates but a safer option would be to shim the stock spring with a 6mm/ 0.250" shim. I found some 1.2mm thick washers that are perfect for this and use 5 of them.

Make sure whatever you use as a shim has a hole through it's middle.
 

DaSuprawolf

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ChicagoLand
and most 10mm nuts work good too.
and cliping will be a little lagy but make up for it on the top end, right?
and the oil pan, doesent horse power freaks have one? not sure.
geese, im not sure about anything, LOL
 

IJ.

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Aaron: If you shoot for 10 psi per 1000 rpm pressure this gets you in the ballpark, only way to achieve this in a 7M is to shim the pump.

Where it all goes a little wrong is when people think "more is better" and wind up with a relief that barely opens as the spring is coil bound.
(think WG Boost Creep)

I bumped up my pressure slightly for this build after seeing the condition of my last set of bearings.
 

supramic

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magnolia DE.
bigaaron said:
You guys think the oil pump shim is the best way to go on just a performance build, or on any 7m?

i didnt do alot of looking for an aftermarke oil pump i just fighured that no one made one for the 7m
 

supramic

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magnolia DE.
ok guy how many washers and what size should i go with
what i mean is what is the psi + withe each washer and what does the 7m have stock , i thought it was like 30 or so

has any one switched to a small block 350 oil pump sping and if so what kind of pis+ did you see
 
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IJ.

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Most of the 7M leaks open around 40 psi......
(squirters are a little lower but the cooler relief opens at 40ish)

There is no "formula" for how much preload = psi as each motor will be different due to tolerances/wear.

4.8mm on my last build gave me 75>80 psi above 3000 rpm.
(4 x 1.2mm thick washers)

I don't run the pressure base Cooler on my motors.
 

supramic

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IJ. said:
Mic: If you have a way of accuratly measuring the free length and wire diameter in the 2 springs you could calculate the rates but a safer option would be to shim the stock spring with a 6mm/ 0.250" shim. I found some 1.2mm thick washers that are perfect for this and use 5 of them.

Make sure whatever you use as a shim has a hole through it's middle.
what toold would i use to mesure that sort of thing and what forula do i use ??????? id perfer not to shim cuz i heard the the washers can cause the oil presure to spike
 

Adjuster

Supramania Contributor
I used two washers and a 10mm nut, but I'd leave out one washer if I did it again as the high rpm oil pressure is pretty high when it's cold. (I'm not sure that with this pump, you could get it too high actually to damage the bearings, but it does cause the turbo to smoke if your pushing too much oil pressure into the CHRA. (Mine was BB, and they don't really need as much oil actually.)

When it's all hot, the stock gauge pressure reading is about 50psi at high rpm, and drops to the 20's during idle.

Cold is 80+ and cold idle at 40+. (My accusump gauge has seen a few 120's on there when I've closed the valve after running the car for a few miles, and the oil is still cold. I generally close the valve during high rpm running to save oil under pressure to pre-lube my engine on start up.)

So, it's up to you, but one 10mm nut, or a few washers about the same thickness as the nut would do just fine. (Assuming your not going to run the stock pressure bypass cooler.)
 

Adjuster

Supramania Contributor
No, what I did was fill the accusump with oil and the piston all the way down on the gauge side. Then screwed in the valve and fittings, then hooked up the AN10 line to the engine. There is a schrader valve on the gauge side, and I put 10 psi of pressure on the oil to push it out of the sump. (I've since changed that to 5psi when the piston has pushed all the oil out of the sump, and I'm sure it brings up the pressure as the oil pushes the piston across the tube.)

Anyway, before I started this motor, I pre-lubed it with the accusump, then it started right up no issues. :)

I've changed the oil a few times, and I have hit the switch and dumped the oil from the sump, and then had a "dry" start as a result, but I figured a few dry starts is better than changing the oil and then dumping a few quarts of dirty stuff right back into the new oil.

One more detail. I'm running 10 quarts of oil now v/s the 12 quarts I started with. When I'd run 12, it was blowing oil out the dipstick at times, and also pushing it out my PCV breather at the drag races... With 10 quarts there is absolutely no problem. The dipstick is "full" when the oil is just at the point where the wire is crimped to the flat metal end. (So about 1.5 quarts fuller than "stock" right? Not counting the oil in the lines, cooler, filters and sump.)
 

IJ.

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Greg: Thanks!

So the short answer would have been "yes" ;)
(filling the accumulator first qualifies as bleeding)

I run mine so at idle the Oil level isn't high enough to contact the crank so this would probably be much the same for your setup no at 10 qts!
 

supramic

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Feb 4, 2006
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magnolia DE.
wow thatks guys i think i finally have a plan to how im going to work the bottom end
adjuster: im a little confused on what your talking about, with opening and closing some valve ???? are you running a oil tank ?
i also dont know what infomation to put in the formula. do i place the thickness of the spring in the radius slot? if so then what do i place int the time per sec box???? sorry to keep asking questions guys i just like to understand stuff.
 

Adjuster

Supramania Contributor
Radious slot? Time per second box? Hello? I'm thinking your running low on blinker fluid, and your muffler bearings are worn out man....

Valve is on my Canton Accusump. It holds a few quarts of oil under pressure that is then forced into the engine if the oil pressure drops below a set point. (Like when your car is speeding up, slowing down, or turning and you slosh the oil off the pickup point.... Your engine never runs without oil pressure.)

Here is where I mounted mine. Makes a nice subwoofer grille...
p258091_1.jpg