engine oil distribution upgrade.

brandnu6

Member
Joined
Oct 7, 2014
Hello. Are there any "proven" ways to increase "oil distribution" to the rear of the motor? I have heard that you can tap into "high pressure" side of oil pump, route a line to rear of block and tap in. Not exactly sure were to tap in, but this is supposed to supply "more oil" to back two rod bearings? I am rebuilding the motor. Now would be the time to make any changes/upgrades. Thanks...
 
Dry sump oiling system and abandon the stock pump is the only proven method. Barring that, if you have adequate pressure and the oil remains within a sane temperature range and the engine is built properly, everything's going to get enough oil. The back two bearing thing is because if you have inadequate pressure, the things furthest from the pump starve first.
 
The Earl Brown front cover mod is what most do if not going dry sump.

 
depends how much HP you plan on making...weak spot is oiling to #2 and #3 mains and #5 and #6 rods.

for a bone stock rebuild, TT chip and 93 pump gas - I probably would not do anything. that'll yield about 315bhp or about 250 at the wheels. As-built factory components are maxed out about 350-360 bhp.

for 350 to mid-400 bhp or so build, yes, timing cover oil passage mods.

it's when you're approaching the 500 bhp mark to 600 bhp that mods to the oil passages within the block should be reviewed as well as oil pump mods plus the previously done mods to the timing cover.

while the attached pdf was published nearly two decades ago, this Jack Merkel build covered step-by-step in GM High Tech Performance mag discusses the above.

if you're building a race engine, the second pdf attached write-up discusses the external oil line to the rear of block. but I don't know that you're planning a high HP build where that is suggested.

if your plan is over 600bhp, I'd think about a stage off-center block for longevity. seem to be a bunch of split in half 109 blocks recently found by various folks during this post season teardown inspections. find those discussions on bison's & Steve K's tech group on f*book
 

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if your plan is over 600bhp, I'd think about a stage off-center block for longevity. seem to be a bunch of split in half 109 blocks recently found by various folks during this post season teardown inspections. find those discussions on bison's & Steve K's tech group on f*book

The split 109s I've seen are on their x-teenth rebuild and were rode hard the whole time. The original blocks are starting to fatigue cycle out on us.
 
depends how much HP you plan on making...weak spot is oiling to #2 and #3 mains and #5 and #6 rods.

for a bone stock rebuild, TT chip and 93 pump gas - I probably would not do anything. that'll yield about 315bhp or about 250 at the wheels. As-built factory components are maxed out about 350-360 bhp.

for 350 to mid-400 bhp or so build, yes, timing cover oil passage mods.

it's when you're approaching the 500 bhp mark to 600 bhp that mods to the oil passages within the block should be reviewed as well as oil pump mods plus the previously done mods to the timing cover.

while the attached pdf was published nearly two decades ago, this Jack Merkel build covered step-by-step in GM High Tech Performance mag discusses the above.

if you're building a race engine, the second pdf attached write-up discusses the external oil line to the rear of block. but I don't know that you're planning a high HP build where that is suggested.

if your plan is over 600bhp, I'd think about a stage off-center block for longevity. seem to be a bunch of split in half 109 blocks recently found by various folks during this post season teardown inspections. find those discussions on bison's & Steve K's tech group on f*book
Hi Anthony. Those pdf's were very educational. I will take some more time to read them, so I can retain what I have read. You are right, when you listen, you learn. Someone once said, "knowledge is power." By the way, I am not building a "high horsepower" motor. I'm hoping for around 350-375 wheel. we'll see. Take care...
 
hey Andrew, most definitely. there was one asked about just welding up the hairline crack in lifter valley and running it. I see the posts and accompanying pics...folks have nice workshops and tool setups, they're doing their own tear downs and some form of re-assembly post machine shop assembling the short block for them. it's just surprising to see folks with that level of mechanical ability wonder about fixing a cracked (and fatigued) block.

Cheers to the 3rd day of Christmas and the upcoming warmup for New Years!
 
hey Andrew, most definitely. there was one asked about just welding up the hairline crack in lifter valley and running it. I see the posts and accompanying pics...folks have nice workshops and tool setups, they're doing their own tear downs and some form of re-assembly post machine shop assembling the short block for them. it's just surprising to see folks with that level of mechanical ability wonder about fixing a cracked (and fatigued) block.

Cheers to the 3rd day of Christmas and the upcoming warmup for New Years!
I hear you. I think It comes from a fundamental misunderstanding of cast iron. People think it's like steel and you run a bead and melt it back together and it's fine again. It just don't work that way. It's closer to glass or a ceramic than steel. Once the crack starts, there's no stopping it.
 
... Those pdf's were very educational. I will take some more time to read them, so I can retain what I have read.... I'm hoping for around 350-375 wheel. we'll see...

there's a lot to unpack in those pdfs. you're aiming for mid to upper 400bhp...many folks aiming for the 500bhp neighborhood end up over building for their current goal in case there is the desire for more power one day in the future. the "I want to see 450 so I'll have it built for 550" idea. and the build it for 700bhp because it will live at mid-500's and I won't have to worry about anything, including detonation with a great tune. at 710 with detonation, it becomes scrap.

that concept was a heck of a lot easier to do in 2019 and earlier years. currently, there are long lead times for parts. some of our best known Buick builders are more than a year out with back log. and roller cam blanks - some have been waiting since 2020 for their cam.

besides the long lead times and shortage of parts, cost of parts and labor for a forged rotating assembly, roller cam, maybe roller valvetrain, and machine work to block, main caps, heads, forged crank add'l machining +mallory metal, etc. have like doubled vs just a few years ago in 2019 and earlier.

with the above in mind, read through this thread below. there's spot-on input from bison, turbodave231, and Scooby. perhaps no need to overbuild if you just stay at your goal of mid-400bhp and enjoy the ride.

 
there's a lot to unpack in those pdfs. you're aiming for mid to upper 400bhp...many folks aiming for the 500bhp neighborhood end up over building for their current goal in case there is the desire for more power one day in the future. the "I want to see 450 so I'll have it built for 550" idea. and the build it for 700bhp because it will live at mid-500's and I won't have to worry about anything, including detonation with a great tune. at 710 with detonation, it becomes scrap.

that concept was a heck of a lot easier to do in 2019 and earlier years. currently, there are long lead times for parts. some of our best known Buick builders are more than a year out with back log. and roller cam blanks - some have been waiting since 2020 for their cam.

besides the long lead times and shortage of parts, cost of parts and labor for a forged rotating assembly, roller cam, maybe roller valvetrain, and machine work to block, main caps, heads, forged crank add'l machining +mallory metal, etc. have like doubled vs just a few years ago in 2019 and earlier.

with the above in mind, read through this thread below. there's spot-on input from bison, turbodave231, and Scooby. perhaps no need to overbuild if you just stay at your goal of mid-400bhp and enjoy the ride.

Hi Anthony. How are you. Happy New Year. Just read link. Yes, the three you mentioned were all correct. No need to "overbuild." For me, I'm just looking for reliability more than anything else. Reason being, I am process of taking motor out for SECOND rebuild. No Alky. No race gas. No track time. 3000 miles later. Lots of noise and metal in oil pan. You are right about lead time. I bought another 212/212 flat tappet and lifters, "Comp Cams." Those were in stock. I purchased a set of "Champion heads" from Richie, and ported intake. New 5558 Gen ll B.B. turbo "Precision." Stretch I.C. coming, shrouds and tanks take time to weld. I plan on getting T.A. front cover, if I'm lucky. I will rework "oil pump." 2-3 oiling holes. opened up to 3/8, thanks to information you provided. Car ran great before it died. No knock ever. 42 lb. Inj. / 93 oct. chip, "Eric Marshall." 17 lbs. boost. "Tin-man cold air, 62mm T.B. "Steve Monroe." T.A. downpipe and headers. There's probably more. Racetronics 340 pump /hotwire set-up. W.B. O/2, 14.7. Electric F.P. gauge in the car. 1987 Turbo-T- Limited. Leather and roof. Really nice car. I will take my time as I always do. Make sure I double and triple check everything. I can only control what I do, not someone who claims they have worked with "109" motors. It's not a small block Chevy! Talk to you later man, take care of yourself.
 
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