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Search found 318 matches

by RDY4WAR
Wed Sep 28, 2022 5:17 pm
Forum: Engine Tech
Topic: SBC & oil pressure at idle
Replies: 16
Views: 467

Re: SBC & oil pressure at idle

What temperature was that though? The high today in Belgium was about 55°F. At 55°F, the 15W-40 oil is 400-500 cSt. It's about 150 cSt @ 85°F and about 100 cSt @ 100°F. It's much easier on the drill to pump 100-150 cSt oil than it is 400-500 cSt oil. If the dyno guy's drill was struggling to stir th...
by RDY4WAR
Wed Sep 28, 2022 9:07 am
Forum: Engine Tech
Topic: SBC & oil pressure at idle
Replies: 16
Views: 467

Re: SBC & oil pressure at idle

The relief spring does not increase pressure. It only increases the max pressure at which oil is bypassed. Your dyno guy is an ID-10-Tango. Take it somewhere else. I aim for 15-20 psi at hot idle with a max of 65-70 psi. Anything more than that just increases oil aeration and power loss with no bene...
by RDY4WAR
Thu Sep 22, 2022 11:06 am
Forum: Engine Tech
Topic: Does quench affect power?
Replies: 253
Views: 6939

Re: Does quench affect power?

It's always puzzled me why people join technical forums or groups and then question anything that remotely steps outside the box. How dare you deviate from the way things were done 50 years ago. lol My personal favorite is those who say "Trust the engineers at the OEM." You mean the engineers that s...
by RDY4WAR
Thu Sep 22, 2022 8:45 am
Forum: Engine Tech
Topic: Does quench affect power?
Replies: 253
Views: 6939

Re: Does quench affect power?

There's been less complex topics go 20+ pages. This one is just getting started.
by RDY4WAR
Wed Sep 21, 2022 9:04 am
Forum: Engine Tech
Topic: Does quench affect power?
Replies: 253
Views: 6939

Re: Does quench affect power?

When dealing with matters of great complexity, it is normal to simplify to assist understanding. But that comes with a substantial loss of accurcy and often even with misdirection. You hit a bunch of nails on the head with that statement. Nowhere is this more prominent than in lubricants. Those ove...
by RDY4WAR
Wed Sep 14, 2022 4:07 pm
Forum: Engine Tech
Topic: Does quench affect power?
Replies: 253
Views: 6939

Re: Does quench affect power?

Add .005" for rod stretch at 7200 rpm.

Add another .005" to cover rod and main bearing clearance.

Add .010" for piston rock.

.0082" + .005" + .005" + .010" = 0.0282"
by RDY4WAR
Wed Sep 14, 2022 8:53 am
Forum: Engine Tech
Topic: Does quench affect power?
Replies: 253
Views: 6939

Re: Does quench affect power?

There's other factors like the piston weight, rod length, and stroke that must be considered. A 4.00" stroke with a 6.00" rod and 600 gram piston will have 5,193 lbs of upward inertia at 7200 rpm. A 3.25" stroke with a 6.25" rod and 400 gram piston will have 2,658 lbs of upward inertia at 7200 rpm. ...
by RDY4WAR
Fri Sep 09, 2022 11:44 am
Forum: Engine Tech
Topic: Does quench affect power?
Replies: 253
Views: 6939

Re: Does quench affect power?

Remember the other side of the squish velocity equation which is the quench area size of the head. More gap but more quench area could cancel out to give a similar squish velocity.
by RDY4WAR
Fri Sep 09, 2022 10:13 am
Forum: Engine Tech
Topic: Does quench affect power?
Replies: 253
Views: 6939

Re: Does quench affect power?

It's also why Pro Stock uses steel rods. I can't show the piston top, but here's a picture of the underside and the rods. This engine had >40 passes on it. You can still see the dimple in the bearing coating from the dial gauge.
Pro Stock Teardown - Jeg Coughlin Jr.jpg
by RDY4WAR
Thu Sep 08, 2022 2:17 pm
Forum: Engine Tech
Topic: Does quench affect power?
Replies: 253
Views: 6939

Re: Does quench affect power?

I've seen a Pro Stock DRCE 3 head/chamber and have a piston here on my desk. I'll reach out and see what I can or can't disclose to bring some resolution to this discussion. There's no softening of the chambers in Pro Stock either. The piston I have here has some slight marking to the quench areas ...
by RDY4WAR
Thu Sep 08, 2022 12:15 pm
Forum: Engine Tech
Topic: Does quench affect power?
Replies: 253
Views: 6939

Re: Does quench affect power?

I've seen a Pro Stock DRCE 3 head/chamber and have a piston here on my desk. I'll reach out and see what I can or can't disclose to bring some resolution to this discussion. There's no softening of the chambers in Pro Stock either. The piston I have here has some slight marking to the quench areas ...
by RDY4WAR
Thu Sep 08, 2022 11:58 am
Forum: Engine Tech
Topic: Does quench affect power?
Replies: 253
Views: 6939

Re: Does quench affect power?

I've seen a Pro Stock DRCE 3 head/chamber and have a piston here on my desk. I'll reach out and see what I can or can't disclose to bring some resolution to this discussion.
by RDY4WAR
Wed Aug 31, 2022 6:48 pm
Forum: Engine Tech
Topic: Does quench affect power?
Replies: 253
Views: 6939

Re: Does quench affect power?

Tighter quench gives a higher squish velocity which means a higher turbulent flame speed. This improves throttle response and power with less timing required. Anytime you have to advance the timing for peak power, it indicates less efficient combustion.
by RDY4WAR
Fri Aug 26, 2022 10:42 am
Forum: Engine Tech
Topic: 4 Valve Head: Single Central Spark Plug vs Dual Spark Plugs
Replies: 75
Views: 2213

Re: 4 Valve Head: Single Central Spark Plug vs Dual Spark Plugs

Ditch the 2nd plug, put the one in the center, and put in bigger valves.
by RDY4WAR
Sat Aug 13, 2022 1:10 pm
Forum: Engine Tech
Topic: Centistoke oil rating
Replies: 19
Views: 833

Re: Centistoke oil rating

A good estimate for bearing temperature in a performance engine is 40-60°F above sump temperature. High end endurance engines like NASCAR cup engines see upwards of 75°F rise through the bearings, especially stretched out at Daytona. A daily commuter cruising easy down the highway will be 20-40°F ab...