FX Holden Race Car Project

[vlad01]

That totally makes sense as it at the end of the line, drained by centrifugal forces and that oil has to pass through the main bearing and it's groove, crank drilling and all, and that drilling only connects to the greater supply only part of the crank revolution, and the rest of the time it is completely cut off.

Also, we must consider flow volume and not just pressure alone. Pressure indicates only part of the whole dynamic, mainly the restriction to that flow, on the flip side, pressure in a way is also what drives that flow.

[Holden202T]

ok here we go .....

original motor, main gallery is 15 or 16mm i cant recall ..... runs along the cam side of the engine, feeds to all the lifters, also from that main gallery feeds down to the 7 main bearings, then every main feeds the rod bearings. Then every odd main bearing number feeds back up to the cam bearings, and number 1 also feeds the timing gear oil squirter.

the feed from the oil pump through the block to the main gallery from memory the smallest point was 11mm.

ive always had great oil pressure at the pump, but continued to chew up #1 rod bearing .... i've never been able to measure the main gallery pressure in the past.

originally i ported the pump and smoothed transitions to the block etc external pickup from the sump to the pump, this was mainly for the stud girdle, the original pickup doesnt fit.

then i was pumping it all to the top of the motor, so i fitted restricted tips to the pushrods to help with that, and it was at this time i built a new sump to increase capacity.

still killed #1 rod bearing, at this point i came to the conclusion that it was lack of oil into the motor that was the issue, we also noticed that #6 was slightly worn, just not as bad as #1 and as the bearings got closer to the centre of the motor they were progressively better looking. we also at this point decided to shave the sides of the rods to increase rod to crank clearance.

so i added the front and rear holes in the main gallery, so if needed i can feed directly to them, and also be able to use a sensor to measure. i also drilled out the main port in the side of the block that feeds into the main gallery to about 14mm ... i've worked out that alone could potentially increase flow by 40% or more.

ultimately time will tell, but im hopeful that the issues are resolved. i've also spoken to people who circuit race 202's for ideas on what they do, which if anything will be more than i need as im not holding it flat lap after lap.

[immortality]

ive always had great oil pressure at the pump, but continued to chew up #1 rod bearing .... i've never been able to measure the main gallery pressure in the past.

I think this is a issue with a lot of motors. Pressure at the pump or filter is irrelevant, what is happening in the main oil gallery(s) in the block is the true info we need.

[heff0018]

Hope you have it all sorted now. Just for interest what oil and bearing clearances are you running? I am not running to the revs that you are, I shift at 5k because I don’t have the valve spring pressure to go much higher and rely on engine torque but oil pressure has been in the back of mind. My main and rod bearing clearances were at 0.0015. I have just installed a larger turbo with an electronic boost controller and the ute is in with dyno guy now so will post an update soon. Cheers

[Holden202T]

i dont know the answer to that, but i know when i measured the h beam rods against a stock one it was like .005 thicker i think, its need to ask the engine machinist what it ended up ...

[vlad01]

Going by what you said about the bearing getting better towards the middle, then you probably have figured it out. I guess that's the down side of a inline 6, they are so damn long and have so many bearings to feed, doesn't help either that their inherent design is wanting the crank to twist and wobble around like a sausage.

[delcowizzid]

https://youtu.be/G8qMsKNdV44?si=rBwcgDilWfAJyUaW
Well worth the watch

[Holden202T]

this video is interesting, i am actually running king racing bearings haha!

actually correction, in the past i had king racing, but i couldnt get them for this build but i was able to get acl race series bearings!

[Holden202T]

not much to report, oil pressure looks good, car ran pretty consistent and drove onto the trailer

https://www.youtube.com/watch?v=q6dSCs99oGg

[Charlescrown]

Certainly did a number on the Gallant. I wonder if an electric pump supplying oil to each end of the crank would help.