dart ford block

[Einar Glasius]

I'm building a 427 Windsor using the 9.5" deck aluminum dart block. This is a street engine for a A/C cobra replica, and will be wet sumped. There are only four little holes for oil drain back in the lifter valley. I know this block is for dry sumped engines, but what do you suggest I do for oil return to the pan, mill out the center area? Or maybe just some return holes. Has any body had any experiance doing this? Also this is my first aluminum block build. Is there anything I should be aware of with aluminum blocks vs iron. Main or lifter bore clearances, ect.

Thank you, Einar

[PRO 1]

It is not necessary to add additional holes, the ones we drilled through in the valley are adequate to handle the return. The block is a wet sump, and dry sump as well so it will work with wet sump without any problems.

Most engine builders will alter their clearances, how much varies depending on the engine build, the use (application), and parts being used. You may want to consult with an engine builder on this and let them know your use.

Thanks
J

[Awesome Bill]

I'm building a 427 Windsor using the 9.5" deck aluminum dart block. This is a street engine for a A/C cobra replica, and will be wet sumped. There are only four little holes for oil drain back in the lifter valley. I know this block is for dry sumped engines, but what do you suggest I do for oil return to the pan, mill out the center area? Or maybe just some return holes. Has any body had any experiance doing this? Also this is my first aluminum block build. Is there anything I should be aware of with aluminum blocks vs iron. Main or lifter bore clearances, ect.

Thank you, Einar

I know they say you do not need to add any holes, but we have found on the dyno, without restrictors, that the oil will stay up top to long when bring the engine up slowly. We usually find this after 10 seconds or so on the pull. We open the drain back holes up to 1/2" and add one 1/2" hole in front of the #2 cam bearing bulkhead and use a very generous radius around all the return holes for better funneling affect for quicker drain back. This takes care of oil pressure fluxuation @ higher rpms and extended rpm. This is only what we do, from what we have seen on the dyno. We also do this with the Iron Eagle Chevy wet sump conditions.

[Einar Glasius]

Thanks for the help guys. Bill, I've heard the same thing from another builder, thanks for the tip. Some say to tighten up main clearance .0005 on aluminum blocks, do you agree?

Einar

[Awesome Bill]

No, I do not do that. I have my reasons as we have been there done that.

[Einar Glasius]

Thanks Bill, do then just run the same clearance you would in a iron block? On cyl walls with aluminum blocks, do you have a hard time keeping the walls round? I read that one builder would dyno the engine, then tear it down to rehone the cyl's. Does that sound right to you. I would think by now that type of thing souldn't be nessary.

Thanks for your help, Einar

[Awesome Bill]

Any one who does that has more time to fix it right the second time and did not do it right the first time. That is so old school its rediculous. We did that stuff in the early 90's. Was worth a little but did not mean qualifying or not. As far as keeping cylinder walls round, I have never heard anything so silly. After 2000 hp of NOS or turbo, maybe something could get a little out of round, but naturally aspirated, no. Maybe if you took the bore to 4.200 and shot the H____ of it it might get out of round also.

[Awesome Bill]

I will add on the aluminum blocks, we keep the same stud in the same hole which it was torque to and use the same torque wrench and the same lube when assembly is done. Less than 2% leakage on brand new steel and more importantly aluminum block based engines with the 1-¾ ball nose stud we use and less than that after run. They are already broke in after the assembler has turned it over a few times with our honing procedure.