FX Holden Race Car Project

[heff0018]

well i reckon you'd be able to put enough into it to blow the head gasket out of it

when i first got the FX going it had about 13-15 psi on the gate spring, and with 35% duty cycle on delco flex output it was up to 25psi!

Jeez, 25psi must be interesting

[Holden202T]

oohhh yeah

[Holden202T]

well its been a long year between posts lol.....

so after i found the waste gate issue i put a new gate on it then took it to the dyno to confirm i was getting stable boost control, before we could really get too far with testing (dyno issues) we shut the car down, had lunch and rang the dyno company for some advice, and on restarting the car 40 minutes later we had a knock in the front of the motor

turns out it chewed out another #1 rod bearing, so i still had oil pressure issues.

i spoke to a few people who race 202's and got some plans of what i needed to do.

after some measuring i found out the main gallery is like 15mm diameter, with a hole feeding it that was around 11mm from the oil pump, so i set about enlarging the feeds to it.

first task was to modify the oil pump so it sent oil out of the original in from the filter, so i machined the bypass valve section out of it (this was die grinded smooth after this picture)

1.jpg

i also blocked off the bottom hole here that normally fed oil into the filter.

2.jpg

3.jpg

next i machined out the front and rear of the block beside the main gallery area and tapped a thread into it for a pressure sensor (this can also be used to direct feed the ends if needed)

4.jpg

so oil goes out of the centre of the oil filter mounting hole, into extrnal filter then back into the block through an enlarged port (above the dizzy hole) which calculations say it should provide around 30-40% more flow than stock port size.

5.jpg

we also machined a bit of the side of the h beam rods as measurements showed that they were maybe a bit on the small side for clearance at high rpms (oil cant escape fast enough and overheats)

so around 12 months later i got it all back together and ready to hit the dyno again!!

initial testing was showing at least better oil pressure but not necessarily quite enough at the main gallery (it was around 10psi less than filter pressure), also showed a nice flat 11psi of boost pressure throughout the entire run!

so i screwed the adjuster on the oil pump right in as it on had about 2-3mm of adjustment left, needless to say that last few mm is where all the adjustment is!

so here you can see green is the filter oil pressure sensor and the blue one is the front of the main gallery pressure, white line in the graph is ~7000rpm

oil pressure.jpg

so i was pretty happy with that! Also on that last run i moved the rotary dial from setting 1 (10psi) to setting 5 (15psi) and it looks like that worked pretty well too!

dyno run.jpg

its been a long road but i think i finally have the oil pressure gremlin off my back! bring on Gunnedah end of july!

[Charlescrown]

Hope you have finally solved the oil pressure problems. I can only think the 202 with a bigger crank diameter than the 186 plays a part with the higher surface speed. From past videos it certainly goes like a scalded cat. Gunnedah will be the big test. Good luck.

[vlad01]

Damn! Well done on not setting the whole thing on fire! That's some persistence solving a real hairy issue the likes of oil supply/pressure,while bearings were already failing,
multiple times too.

[Holden202T]

i was almost all but out of ideas if the latest mods didnt work i can tell you that now!

[immortality]

You definitely have all the oil pieces now.

I follow some of the US Drag & Drive and guys with $100K billet alloy engines have oil pressure problems. Going down the strip doing 6 second passes they have 100psi+ oil pressure and then when they hit the road and everything gets hot and expands their oil pressure drops through the floor.

One of the very first oil pumps I ever played with was a Holden 202 after reading a book by David Vizard so seeing your oil pump pics brought back some memories.

[Holden202T]

yeah David Vizard has some good books out there!

[vlad01]

Which bearings were failing? Just the big ends? If so, was there any evidence of wear/oiling issue on the mains?

Some oiling issues come down to bearing clearance and design. Taking a page from the Buick which (ignoring pre-gearotor engines) have excellent oiling (also ignoring ecotec for different reasons). They have massive bearing diameters, but also very tight tolerances. Typically they ran 0.8-1.2 thou for the mains, and around 1-1.5 thou on the big ends iirc. They designed them to always have mains tighter than the big ends, so that the oil wasn't predominately bled out at the mains before feeding the big ends, the tight mains forced the oil to have to find the least resistance at the big ends. Those engines seldom wear or fail bearings, even with hard use and 100s of 1000s of Km. Looking at the FH v6 engines from guys I talked to that own them, the bearings do great and they go round at high rpm for long periods. Of course, they are dry sump, but the main pressure and volume is all supplied by the factory gearotor pump.

Early regal, GN engines etc... had issues because the cam driven gear pump in the timing cover sucked which is probably similar to your issues, later ecotec had occasional core drilling shift issues that blocked the passages by the cam bearing shells. The other big one with ecos I found out later is their sumps suck. I spoke to ASR who's primarily roll is making competition sumps, and they always build ones for the v6 using the Buick sump, they stated the cross bracing and the large cross bolted main caps barricade the cylinder pairs from draining back to the sump correctly, Buick did not have this issue as is the main reason their oiling is so good, I mentioned the sump with the eco to make that distinction from the otherwise good bottom bearing oiling setup. I feel it's always good to study other engines that are known good in that regard, so you can see what has been done right, it often gives clues where to look when you have problems with an existing design.

Anyway, I digress. Maybe if you haven't already, sus the bearing situation out while you're there, just for the sake of ruling that out.

[delcowizzid]

The pressure at the bigend is very low around 1/4 of the pressure at the mains some smart cookies measured the actual pressure there's a video on YouTube about it