Camshafts' oil tolerance

[Wolf_Tm250]

Hello ! Let me explain: engine is a modded Toyota 3SGTE ( 2000cc turbo - 425 4whp ) It's 1000 miles old... the running in, a map session, and a track session... only 6 laps because I cracked a weld in the ext wg feed pipe. In those 6 laps oil reached 120 deg C., not more, but oil pressure wasn't so high... 1 bar at idle AND 2.5 bar at 4000 rpm. That's why I put off the stock oil pump, and bought the $$$ WRC-TTE oil pump... ( and even because my oil squirters are TTE - open at 3.7 bar ). When changing the oil pump, I also checked the valves' clearance.. BUT I looked at the camshafts and it seems to me that they were worst that they should be... Imagine a new camshaft...with its shiny pins... now, after 1000 miles, pins have some darker zones, yet shiny, but darker. the pins are not deeply digged as if some dirt passed with oil... at the most they seem like they were nearly to seize ! Poor oil pressure ? Or too little oil clearance ? What oil clearance do you use in your engines ? FYI camshaft journal diameter is 26.97mm ( 1.0618" ) TIA. Bye...

 

[AEHaas]

The oil pressure and temperature seems good for the track. I would say the viscosity and flow are matched. Now if the oil was to get to a higher temperature then the pressure would go below 10 PSI / 1,000 RPM and a thicker oil or faster pump would be needed. If the engine is designed for racing then the pump should be good for it as well. As is, it seems the oil system is just right. There is correct pressure (and therefore good flow) and relatively low oil temperature for the track. aehaas

 

[mechtech]

Camshaft pins?

 

[Wolf_Tm250]

Thanks for the advices, mates... yes, I intended camshafts' pins oil clearance...

 

[JohnBrowning]

You can modify the common rocker rail to increase oil flow. You can cut sprial groves inside the bore of the rocker tube to direct the oil flow and to lighten the tube. You also drill and chamfer additional oil holes along the sprial cuts. This has been done for a long long time on 22RE engines. Are you running extremely high valve spring pressure? I had issues when running triple valve springs on some Toyota engines. The oil had to be a premium oil like Redline,Motul,Penrite,M1 15W50 etc..... I also think that generious use of EP assembly lube. The oil pressure seems low to me but I do not have the spec.'s anymore. I am thinking though that at idle it should be 25-35 PSI and should gain 10 PSI per 1000 RPM's. 14 psi seems low to me for idle. When you replaced the cam did you replace the followers??

 

[427Z06]

I don't have any specs for the 3SGTE engine but 1 Bar at idle with the engine at operating temperature is at the high end for many engines. At 4000 rpm, 2.5 Bar seems low to me. I would expect more like +3.5 Bar at operating temps with a 10w40 syn. What is the idle speed you measured the oil pressure at? Oil type/grade? When the engine was rebuilt, the clearances may have been set so that you need to run more viscous oil to achieve the oil pressure you want. Did you use a camshaft lube when breaking it in? A small, cheap, poorly plumbed oil cooler may be adding to much restriction. [ May 17, 2006, 02:04 PM: Message edited by: 427Z06 ]