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304 355" build thread

Deuce

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Forgive my ignorance, but what's the point of this mod if you already have crossover at no.1 cam bearing?
Does it supply more oil to the main bearing? I have done the no.1 bearing crossover, plugged the cam bolt and timing chain oiler, but haven't plugged or reduced flow at 4 where most people tap and bolt up.
Crossover at #1 is to supply driver side lifter gallery via a cam bearing that isn't supplying a main.
#4 cam bearing blockage is to stop bleeding oil to driver gallery when it should be feeding #4 main and rods #6&7
Single pipe mod, aka feed #4 internal mod - basically is just to even up oil pressure along the length of passenger side lifter gallery. The object is for #4&5 to have the same oil pressure available as what #1&2 have.

I don't have hard data, but someone has measured the pressure difference in a running engine front to back and supposedly the results were eye-opening.
Again, I don't know what the numbers were, so am only speculating and repeating what I possibly read a decade ago.
 

Shaneo 355

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Ok awesome to know
If I was to do all the above except block off or restrict no4 bearing (reason being the engine is already built, running and in the car) i would have I'm guessing a very reliable, although overkill oiling system for my 355?
 

Deuce

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Ok awesome to know
If I was to do all the above except block off or restrict no4 bearing (reason being the engine is already built, running and in the car) i would have I'm guessing a very reliable, although overkill oiling system for my 355?
The modifications are to assist and support reliability at sustained high rpm.
I think adding #1 crossover without doing #4 block off (or restriction) could feed too much to the driver side gallery and not help mains/rods at all.

This is really a question for @Smitty as he circuit race's and knows a lot more about this than most.
 

RevNev

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Forgive my ignorance, but what's the point of this mod if you already have crossover at no.1 cam bearing?
Does it supply more oil to the main bearing? I have done the no.1 bearing crossover, plugged the cam bolt and timing chain oiler, but haven't plugged or reduced flow at 4 where most people tap and bolt up.
I'm not sure what the mod is intended to achieve. The only mod I'm aware of to increase oil flow to the crank, is bronze lifter bores with smaller holes restricting oil bleed off to the lifters.
 

Deuce

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Oil pump, photo dump:
Messenger_creation_D41E78DE-7A45-4583-A806-6E97A709150A.jpeg
Messenger_creation_0F4C0DA8-60A9-4C9C-8ADC-4AA521A4212C.jpeg
Messenger_creation_20D472A3-6EF6-446C-B55A-9791919A893E.jpeg

3 progress shots of sanding the mating surfaces flat. 240grit on a flat piece of glass, rotating my grip while doing circles with it, or figure 8's
Messenger_creation_9D19C372-72ED-400A-9DCA-323D2A7163AB.jpeg

Messenger_creation_BDB18AD4-5C43-4017-A385-50BB21C591F5.jpeg

The gasket fit up.
Gears are about 2thou proud, gasket is 26thou new from memory.
Messenger_creation_9A4FB3C4-211D-4BDD-B5A9-1DB9ABC9FAC0.jpeg

Bolts torqued to spec.
Aviation sealant.
Messenger_creation_021F861F-8ED1-42CC-BB6A-C85546687C79.jpeg

Same for pump to block.
Messenger_creation_D659BD11-C07D-4D80-B98C-3ADE057D7370.jpeg

All pump passageways are a minimum 16mm with radiused entry/exit. And then the stock filter mount was 14.6mm. So with the help of my neighbors lathe, we took the centre to 16mm (the hex is about 15-15.6, but I didn't want to remove that or I couldn't do it up tight).
Messenger_creation_203D48F3-77A3-42C0-A822-FCE7B286C32E.jpeg
Messenger_creation_BE367D2B-506C-43B2-A39D-44E9975CEE81.jpeg

Then a radius on the exit area of the mount and finish pump assembly.
 
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Immortality

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Borrowed from the FSM....

1.10 LUBRICATION
Pressurised lubrication (refer to Fig. 6A2-10) for engine internal components is provided by a positive displacement
gear type oil pump, which is driven by a short drive shaft, and a helical gear located on the front of the camshaft. Oil
from the reserve held in the oil pan is drawn through the screen and suction pipe to the low pressure (suction) side
of the oil pump via drillings in the cylinder block. Oil under pressure from the oil pump passes through a replaceable
full flow oil filter cartridge, where foreign debris and impurities are trapped within the filter elements.
Clean oil is supplied via drillings in the oil pump body and the cylinder block transfer passage, to the left hand (main)
oil gallery, which is interconnected to the right hand oil gallery by a groove and drilling in the No.4 camshaft support
webbing.
The oil galleries are located above and adjacent to the camshaft.
The No.1 camshaft bearing oil supply is provided by the right hand gallery, and the No.1 crankshaft bearing oil
supply comes from the transfer passage. All the other camshaft and crankshaft bearings are supplied by the main
oil gallery, via a series of grooves and drillings in the cylinder block.
A metering nozzle pressed into a drilling that intersects the supply passage to No.1 crankshaft bearing, discharges
oil where the timing chain engages the crankshaft sprocket. Distributor drive lubrication is provided by an overflow
pressure relief aperture in the No.5 (rear) camshaft journal.
The rocker and overhead gear are lubricated through hollow push rods, using oil supplied from the hydraulic lifters.
The adjacent oil gallery supplies each bank of lifters. Excess oil drains from the overhead gear through apertures in
the cylinder block back into the oil pan

So basically put, the entire drivers side oil gallary is supplied oil by a hole drilled in the cam bore groove at the no4 cam bearing which is potentially taking oil volume away from the cam/main bearing as well as the 5/6 big end bearings. By drilling the hole at the No1 cam bearing which is fed directly from the main oil feed gallary coming from the pump you are ensuring good volume to the drivers side lifter gallary and all the oil at the No4 cam bearing can go to where it's needed the most, the mains and big end bearings.

In a ideal world yes you would use bronze lifter bores to reduce top end oiling but that is a relatively expensive machining job where as drilling a few holes in the block is cheap. Then either put some roll pins in your push rods or find push rods with a smaller internal diameter to reduce flow to the top end.

Somewhere I have a diagram that shows the oil flow path really well but right now I can't find it :(
 

RevNev

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Oil pump, photo dump
That's not the Harry Firth/Perkins oil pump mod.

The Firth/Perkins mod firstly has the filter bypass valve removed and blocked with a core plug. On the pump cover where the filter screws on, the small core plug is tapped through into the hole below it. Then the slot from the core plug hole is opened up, ported around and radiused to make a larger slot with the sharp edges radiused on the existing oil pump holes similar to the photos.

The mod stops pump cavitation at high rpm forcing oil through the filter into engine oil gallery and unlike the stock pump system, prevents oil from passing through the filter bypass valve and circulating around the pump only showing high pressure gauge readings that isn't reaching the oil galleries. Basically, it turns the oil pump into true positive displacement pump eliminating internal bleed off.

I've still got the block, heads, oil pump etc from our 1998 mechanical roller race engine, I'll see if I can find the oil pump and post some photos. That engine was a 358ci alloy head and made 611hp at 7350rpm we got 4500 race km's wet sump and no oiling problems.
 
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Deuce

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That's not the Harry Firth/Perkins oil pump mod.

The Firth/Perkins mod firstly has the filter bypass valve removed and blocked with a core plug. On the pump cover where the filter screws on, the small core plug is tapped through into the hole below it. Then the slot from the core plug hole is opened up, ported around and radiused to make a larger slot with the sharp edges radiused on the existing oil pump holes similar to the photos.

The mod stops pump cavitation at high rpm forcing oil through the filter into engine oil gallery and unlike the stock pump system, prevents oil from passing through the filter bypass valve and circulating around the pump only showing high pressure gauge readings that isn't reaching the oil galleries. Basically, it turns the oil pump into true positive displacement pump eliminating internal bleed off.

I've still got the block, heads, oil pump etc from our 1998 mechanical roller race engine, I'll see if I can find the oil pump and post some photos. That engine was a 358ci alloy head and made 611hp at 7350rpm we got 4500 race km's wet sump and no oiling problems.
Correct, I haven't re-referenced the relief or blocked the bypass.
My understanding was they work together, and I wasn't sure it was appropriate for this build given street vs race km's and the collapsed filter risk.
I'm looking forward to your pictures though.

I can always remove and replace a pump in place without too much hassle if need be.
 

RevNev

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Correct, I haven't re-referenced the relief or blocked the bypass.
My understanding was they work together, and I wasn't sure it was appropriate for this build given street vs race km's and the collapsed filter risk.
I'm looking forward to your pictures though.

I can always remove and replace a pump in place without too much hassle if need be.
We did the oil pump mod with all mechanical camshaft engines and worked fine on the street using both the Z30 (large) and smaller filters. Back in the day, oiling issues spinning big ends etc, seemed to arise when fitting mechanical or solid camshafts and wasn't much of an issue with hydraulic camshafts producing maximum horsepower at lower RPM.
 

Deuce

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We did the oil pump mod with all mechanical camshaft engines and worked fine on the street using both the Z30 (large) and smaller filters. Back in the day, oiling issues spinning big ends etc, seemed to arise when fitting mechanical or solid camshafts and wasn't much of an issue with hydraulic camshafts producing maximum horsepower at lower RPM.
My projected max HP rpm should be around 62-6300 but may rev to 7k on occasion.
 
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