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I was reading David Vizards book on budget building sbc's. He talks about the need to cool the piston when using nitrous. He breifly talks about drilling a hole through the main saddle for each cylinder and connecting it with a small groove to the oil feed hole. Then pressing a metering jet into the holes to direct the oil to shoot onto the back side of the piston. He says it can drop piston temps by up to 200 degrees.
I had never heard of this before, but have also found something about this on a website but for honda's. Does anyone know more about this? I would do the work myself but have found no information on what size hole or what size jet, or even where to get the jets. Would a machine shop know how to do this? Any help would be great.
The reason I'm thinking about this is the fact I plan on moving to a 250 shot this summer and feel the additional cooling from this would be a considerable advantage for making my engine safer.
those links show something totally different. Though I wouldn't mind using a system that didn't involve drilling. What I'm talking about looks like this even though this is the honda setup.
The oil jets are fitted into the crankshaft mains of the block fed from a slot from the mains oil feed. This can be seen in Figures 6, 7 and 8 below.
groove from main oil hole to drilled hole
jet as viewed from the bottom of the block
as viewed down bore
Some of the stock 350 blocks have piston oil squirters. They were often used in the C60 trucks. My crate 350 for a C60 truck is supposed to have these and a high volume oil pump. I have not pulled the pan off to verify that it has them. But I can tell you that it has the intake rotators and sodium filled exhaust valves that it is also supposed to have.
those links show something totally different. Though I wouldn't mind using a system that didn't involve drilling. What I'm talking about looks like this even though this is the honda setup.
It is the same thing but they feed from a different oil line. Som 'squirters' open at a preset oil pressure so they don't waste oil when the pressure is low.
I know it does the exact same thing, but finding or assembling a setup to go in a 350 would be to pricey and to big a hassle. This seems a good method for street car where there is a worry about this, but in my car I am not overly concerned with the oil usage. HV/HP oil pump and a 7 quart pan take care of that for me.
I installed mine today, I went with Get M for the fixture and part. My only recommendation to anyone is buy a good set of cobalt steel bits. Easy to do, added insurance.
Last edited by Tombowman89; 07-10-2022 at 07:33 AM.
Reason: Adding image
thats the fire right there. Piston oil squirts are IMO absolutely essential for high power applications which use brittle-fracture pistons (non forged). It's one of the reasons the 2jz-gte 3.0L 95-02 engine can withstand 800rwhp indefinitely using OEM cast pistons.
In an LS application using OEM pistons without squirts you need an aux method for cooling pistons after say 700rwhp- either water injection, or Alcohol fuel Flex.
Thank you, I appreciate the supporting statements. If anyone on here is building an engine or is thinking about it give Trevor a call a Get M first and he will tell you why his product is king. Or watch The NRE video of some LS boat engine Tom Nelson shows all the tricks in the book he threw at this engine and it’s brutal what they did to that engine and it lives….
I tend to over do things a lot but if you do this mod you have a lot of added benefits. Reduced possibility for detonation and oil into critical areas those are the reasons I chose to do this my engine is a production GM Vortec block, 11.1 CR, AFR 912 heads, Edelbrock Pro-Flo 4 fuel injection, 383 designed with 7,000 RPM in mind…. Reliably https://m.youtube.com/watch?v=Dx-zPNxsrIs
Last edited by Tombowman89; 07-10-2022 at 07:14 AM.
Thank you, I appreciate the supporting statements. If anyone on here is building an engine or is thinking about it give Trevor a call a Get M first and he will tell you why his product is king. Or watch The NRE video of some LS boat engine Tom Nelson shows all the tricks in the book he threw at this engine and it’s brutal what they did to that engine and it lives….
I tend to over do things a lot but if you do this mod you have a lot of added benefits. Reduced possibility for detonation and oil into critical areas those are the reasons I chose to do this my engine is a production GM Vortec block, 11.1 CR, AFR 912 heads, Edelbrock Pro-Flo 4 fuel injection, 383 designed with 7,000 RPM in mind…. Reliably https://m.youtube.com/watch?v=Dx-zPNxsrIs
Those "Get M" Fixtures are decent and provide the means to accomplish said goal at home.
I like that this Simple Oiling Modification has become much more so a DIY endeavor.
Oiling improvements are often overlooked by Chevrolet Engine owners; as the SBC/ BBC Engine has many nice improvements in regard to Oiling (compared to Buick, Pontiac, and Oldsmobile Engines of the same Era).
But there is of course room for further improvement, such as Modifying/ Machining the Mains with the Grooves that LSx Engines use (I perform this on all Engine that I Build, regardless of Make):
As well as adding the Jets for Piston Cooling:
And Grooving Connecting-Rods, as well as drilling them for additional Wrist-Pin Lube:
And enlarging the Camshaft to Crankshaft Oil Passages in NonPriority-Main Lube Engines:
Down to the smaller changes, like Oil to lube the Camshaft Sprocket/ Timing Chain:
OR:
+
And/ or the Main Thrust bearing:
...And many, many others.
Last edited by vorteciroc; 07-10-2022 at 09:02 PM.
One last thing for those of you wanting to do this, take notice that the studs or main bolts may be an issue because the jet and the main bolt holes intersect. I brought this to Get Ms attention and of course the response was less than favorable in my opinion. The black you see in the hole is the stud threads.
I suggest using studs and shortening the length if need be to achieve proper clearance. Good luck folks.
Back in the 50s and early 60s (283 for example) the factory grooved the surface of the rod where the cap meets it, on the side that faces upward. Squirts oil into the piston on the opposite side as the oil hole passes underneath that spot as the crank rotates. Very eeeeeezy to accomplish with a wizz wheel on the cap instead of the rod; or, if the rod bolt is out, on the rod itself. Of course, in that configuration, it only squirts at the instant the hole for the rod brg aligns with that side of the cap. Butt you ccan groove the bearing circumferentially and get the squirt during many degrees of crank rotation, up to 360° if you want. Eeeeeezyer than drilling the block and all that, even though perhaps not quite as effective or perfectly aimed. Depends on how close to "max effort" you're trying to get.
Per Tom's comment about the lube passage intersecting the main bolt hole, you can use thread sealer on the main bolts. The version with PTFE lubes the threads pretty much the same as goods assenbly lube does, therefore doesn't materially affect torquing the bolts. If you use main studs instead of bolts, you'd use the sealer still, but then of course the whole torque issue kinda evaporates.
I always did EXACTLY what vorteciroc shows for the lifter passage plugs: drill & tap the block for a ¼" pipe plug, then take about a #70 drill to the center of the plug, to lube the timing chain via squirting on the cam sprocket. You can either groove the front cam brg slightly from one of the oil holes toward the front similar to how he shows for the rear main brg to oil the crank thrust, or drill the block as he shows for the cam sprocket thrust, to add lube to the cam thrust surface.
All of those mods STRONGLY argue in favor of a high volume oil pump.
There are SO MANY incredible little details like this that make ALL THE DIFFERENCE between yerbasic backyard yutz that buys the Edelbrock "435 HP" kit and slaps it in an unprepared stock 70s block and then wonders why it only made 275 HP and lasted only 3000 miles, as compared to ... some of the rest of us.
Back in the 50s and early 60s (283 for example) the factory grooved the surface of the rod where the cap meets it, on the side that faces upward. Squirts oil into the piston on the opposite side as the oil hole passes underneath that spot as the crank rotates. Very eeeeeezy to accomplish with a wizz wheel on the cap instead of the rod; or, if the rod bolt is out, on the rod itself. Of course, in that configuration, it only squirts at the instant the hole for the rod brg aligns with that side of the cap. Butt you can groove the bearing circumferentially and get the squirt during many degrees of crank rotation, up to 360° if you want. Eeeeeezyer than drilling the block and all that, even though perhaps not quite as effective or perfectly aimed. Depends on how close to "max effort" you're trying to get.
The rod bearing also had to have the corresponding hole in the side.
12-10-2006, 06:02 PM
