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Author Topic:   OIL PUMP Question????????
Dirt Roller

Total posts: 24
posted May 29, 2005 09:08 PM  
What oil pump to run in a Hobby stock motor?? Bone stock or hi volume?? or hi pressure & hi volume. Is a stock pan good enough or so I need more oil?? Please reply with yalls experience on this topic.

Dirt Forum Champ
Total posts: 5390
posted May 29, 2005 09:33 PM  
I have never had any problem using a mellings hi volume pump. I use a stock pan filled one quart over. If you want to make a mellings high volume oil pump have alittle more pressure, you can do it pretty easy. If you look at the pump on ht eside you will see a hole milled into it. There is a spring that is in this hole along with a plunger. If you take a small punch and tap the roll pin out of the casing (you will have to take the four bolts off and seperate the pump but, you need to seperate the pump anyways and make use there is nothing inside it and everything looks good even though it is a new pump) So once you tap the roll pin out take the part of the pump up the the hardware store and find a thin washer or two that will just fit insidethat hole. What you will do is put everything back together but this time put the plunger in the hole, then the spring and then the washer (no more than .050 thick) . Once you got all that in order, compress the spring down and drive the roll pin back in the hole. What this is doing is increasing the spring rate of the spring, so that it take more pressure before the bypass on the pump opens up. If you like to put your motors together with slack tolerances (I do :0) ) then its a good idea to do it for the increased pressure and volume. Also make sure you either pin or tack weld the pick up to the pump so it doesnt fall off.

nine finger
Dirt Forum Racer

Total posts: 76
posted May 30, 2005 07:49 AM  
stock is more than adequate unless your bearing clearance is to wide.that is why oil pans get pumped dry. stock is a lot better for the distributor also.

Dirt Freak

Total posts: 374
posted May 31, 2005 04:50 AM  
After having run both I agree stock is better overall. Less stress and less oil heating due to relief valve shear. At 5000-6500 rpm stock pump delivers plenty of oil. Do not be suprised if after race oil pressure is barely 20# at idle, that is fine.

Dirt Freak

Total posts: 369
posted June 01, 2005 11:28 PM  
hey just a bit of information i will pass on to your guys you should never run 1 qt over as you can windage the crank (rob hp or worse break the crank)

also the motto i go by is the more oil in the system the better i run an 8qt pan with a oil cooler and dual filters that total 11 qts i have never burned up the oil and never had a problem

Dirt Roller

Total posts: 24
posted June 02, 2005 04:19 AM  
If your going to run a stock pan i would run a stock oil pump,I use a high vol. pump with a claimer pan kit from midwest motorsports,its low budget and works great.

Dirt Forum Champ
Total posts: 715
posted June 02, 2005 04:20 PM  
Stock pan,good pump,one quart over and good clearences rod went boom.No more stock pan for me!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!

Dirt Maniac

Total posts: 143
posted June 02, 2005 08:33 PM  
I use a gated 7 quart pan with a stock pump. No problems as of yet. Ilike the idea of the oil staying in bottom of the pan around the pickup. I've heard the same thing about the distributor also with the hi volume pumps.
Check out my post on the engine forum about oil filter. I had a bad problem with a PureOne from Purolator. I won't ever use another one!

nine finger
Dirt Forum Racer

Total posts: 76
posted June 05, 2005 07:14 AM  
stock pan one quart over = airiated oil= rod out the side of block

Dirt Roller

Total posts: 25
posted June 07, 2005 06:29 PM  
I have run a stock appearing pan with both s****er and windage tray with stock pump. Added a high pressure spring and everything is fine. I have tried high volume pump and sheared off 2 distributor gears in past. Also adding xtra oil is never good thing. Find a different alternative. I usually add like Lucas or STP to oil and seems to somewhat stabilize oil and has definitely reduced wear on engine parts. NOTICABLY

nine finger
Dirt Forum Racer

Total posts: 76
posted June 11, 2005 10:59 AM  
we used to build late model engines mostly dry sump. when we had wet sump motors occasionally they would shesr the pump in two. with the stp and a driver watching the light bearings could be ran again. I really like the stp with alcohol motors

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