[dcobeen]

Aloha,
I have a 6.1 hemi in a Dragster, 1/4 mile racing only, I run .003-.0035 bearing clearences with 60 wt oil and aluminum rods in this combination. I have reaserched and all after market oil pumps (Melling, Manley) are all rated at stock flow equivilant and only offer pressure increases via pump spring replacement. I Would like to hear opinions on eliminating (remove) the piston oil cooler jets that spray the bottom side of the pistons!! In theory, this should raise my oil pressure and increase the oil flow through the engine galleys.
Mahalo DC

 

[dana44]

Welcome to the forum.

So nobody makes a high volume oil pump, bummer. I am hoping you are warming the 60wt oil ahead of time so as to make sure it doesn't remain too thick to make it back down to the bottom fast enough to do any good, Ten minutes of running is usually enough to get it to flow well enough, 50wt would work just as well.

Now, since it makes sense you have the engine apart and everything has been race spec'd clearance-wise, and since the purpose of the oil cooling is for high temp situations for longer driving periods of time, block them off, I don't think they are doing you any good under your driving conditions. This will give you a little more volume and pressure. I am going to assume your crank oil holes are chamfored extra large and the edges rounded significantly to prevent bearings from galling or sticking/ getting dry from the rpm and pressure you will be exerting onto them (even with the clearance you have). You can also increase the passage diameters of the oil galleries to increase volume, and looking at the pump design, if the pressure is increased, the intake and output passages should also be able to be increased, even if opening them requires drilling through the case to open the passage, and then a threaded plug put into the casting afterwards (I looked at a picture, not sure how much access you have to the passages to open them for greater volume).

 

[dcobeen]

Welcome to the forum.

So nobody makes a high volume oil pump, bummer. I am hoping you are warming the 60wt oil ahead of time so as to make sure it doesn't remain too thick to make it back down to the bottom fast enough to do any good, Ten minutes of running is usually enough to get it to flow well enough, 50wt would work just as well.

Now, since it makes sense you have the engine apart and everything has been race spec'd clearance-wise, and since the purpose of the oil cooling is for high temp situations for longer driving periods of time, block them off, I don't think they are doing you any good under your driving conditions. This will give you a little more volume and pressure. I am going to assume your crank oil holes are chamfored extra large and the edges rounded significantly to prevent bearings from galling or sticking/ getting dry from the rpm and pressure you will be exerting onto them (even with the clearance you have). You can also increase the passage diameters of the oil galleries to increase volume, and looking at the pump design, if the pressure is increased, the intake and output passages should also be able to be increased, even if opening them requires drilling through the case to open the passage, and then a threaded plug put into the casting afterwards (I looked at a picture, not sure how much access you have to the passages to open them for greater volume).

Aloha dana44
Thank's for the reply, Yes, I do pre-warm my oil, Pan heater installed. Engine is totally race spec'd, I'll look into increasing flow as you have suggested. Your thought on the subject is the same as mine!! Actually, I may benifit if the pistons produce more heat, they stay chilled with the methanol fuel that I run.
I would attach pictures of my car but don't see a method.
Aloha DC

 

[AC TC]

what rpms are you running?
60 weight is an awfulthick oil and it may be the reson for oil starvation..
since your running meth temps wontbe a problem, you havent considered a 15w-40hdeo?

 

[dana44]

Absolutely right on the temp. I figure you are pushing a higher compression, too? What has been done to the combustion chambers to make some extra power there? Dual plugs are cool and great in a Hemi, and there is a flame front problem that needs altered (in your case) so, if you send me a pm note, if you happen to have a second set of "test" heads, I can walk you through what needs to be done to pull some excess power out of them. Would love to help you out if interested, have been porting for a little over 35 years now (I started early), with some pretty good results on street engines, stock class racing/testing, nothing near your level I am sure.

AC TC, running the clearances on the bearings to help prevent them from galling, being too tight, the lighter oil remains thin, thus is more compressible, and I think the power/force he is exerting on the crank and bearings would easily squish from between the bearing and crank and damage the parts more readily, the heavier and thicker oil, although a little harder to pump (thus the reason he warms the oil), can maintain a molecular thickness to minimize damage. If he were driving it on the street, different animal, this one sounds like an absolute purposeful straight line monster, just looking for some suggestions.

As far as the pictures go, I don't do so well with them either so don't feel bad. Most attach a link to the pictures or site with the pictures.

 

[dcobeen]

For ADTC ,
dana44 pretty much made the statement!!
I run 60 wt to cushion bearings to journals, this is pretty much the rule to follow on an all out drag racing type engine. RPM has gone to 7900 recorded. At that rpm the valve heads tappped the top of the pistons on three cylinders ( change made to forged pistons w/valve reliefs).
Oil flow is not starving,!! I just like to see a little more pressure with the $ that I have invested in this project.
Methanol is currently my fuel of choice (larger tuning window) until I max out the performance. This car runs mechanical fuel pump w hat injector. Methanol system (MFI) setup to eventualy run and add (nitrous oxide + gas) to make cumbustion heat.
OR, Optional nitromethane to 60%.
Mahalo DC