2 oil squirters per cylinder B230FT

It will help to improve the oil supply to the head if it's a pre 88 cylinder head. Volvo had a TSB to drill the supply hole larger to improve supply and hopefully lower the incidences of seized cams.

paraphrased from a Honda document in 2009 covering tech for the third era of Honda's F1 engine development.
pistons must withstand combustion pressures of 7 t and inertial forces exceeding 2 t and temp's exceeding 2000deg C. they began with 4 to 6 holes (oil jet holes) dispensing ~10L/min on pistons made of MMC (Metal Matrix Composite- think Cosworth) but MMC was banned for the 2006 season. so honda returned to the aluminum they used in 2000. pistons now were cracking due to thermal stress (some sections of the pistons were only 2mm thick), so they went to 12 oil jets/cyl then to 24. they were spraying the same amount of oil as the 6 hole jets, just spreading it out as they tried to get around the con rod small end. still they had to retard timing 6.5deg which cost power and mileage - neither good. in the end they went to a 19 hole system. that got them a 25deg C reduction in piston temp and were able to only retard timing 1.5deg which allowed power and mileage to return to an acceptable level.

super interesting article. it is a protected .pdf so i cannot cut and paste relevant sections unfortunately... i can share it tho' if someone will suggest a location...

all the squirters i have seen have a check valve to prevent the squirters from functioning until a set pressure is reached indicating there is sufficient flow to handle them too.. one of the benefits i see is getting more lubrication to the piston pin. yes i run water/meth inj. have for years.
just my $0.02

batter up!

dl242gt said:

It will help to improve the oil supply to the head if it's a pre 88 cylinder head. Volvo had a TSB to drill the supply hole larger to improve supply and hopefully lower the incidences of seized cams.

Click to expand...

I did not know that. Which oil supply hole / galley is this?

I?m guessing the hole in the head from the vertical block gallery to the full-length head gallery.

From TSB 113 July 1985. Reconditioning Camshaft Bearing Surfaces.
Machining of oil supply galley. To lessen the risk for clogging the oil
supply hole should be increased in diameter to 14mm (9/16).

Drilling of oil supply galley should take place from bottom side of cylinder head to a distance of 45mm from bottom side of cylinder head.

So, July 85 is a bit earlier than I thought. In general any of the earlier heads should have this done when reconditioning.

I think those heads didn?t have the teardrop oil transfer cast in the head, or maybe the block?
There?s a head/block combo that results in severely restricted oil flow to the head.

The combo is American oil change habits and B21 engines. That
results in seized cams. Personally, I never had it happen and I've had
many B21 cars.