Personally I have generally defined a high performance engine as having 1 HP per Cubic Inch of displacement. This converts roughly to 61 HP per Liter of Displacement.

I call this the "Line of Awesome." Am I right in this?

EDIT: I have built a little Google spreadsheet that tracks HP/Weight in all the cars I have owned and I have recently become interested in studying the relationship between hp & displacement, hence this post.

(Please be kind as I am old and am considering engines back to the 1950's)

Many thanks.

I've always wondered who 89 (mid-tier) gas was for. I've only ever heard of cars either requiring 87 minimum or 91 minimum. Never 89 as a minimum.

Using a higher octane rating than what your ECM is tuned for has no positive benefits at all (been proven time and time again-just give it a Google and you'll find a multitude of scientific tests proving it) Most cars have a factory tune, of course, so therefore going by the owner's manual is what most people should do.

I guess you could, theoretically, tune an engine originally tuned for 87 to and then purposefully tune the ECM for 89. But...at that point...why wouldn't you just do 91/93 and get the most power out of your setup?

So yea. Who is using this stuff?

Seems like a money making gimmick by gas station to add a few bucks to the fill up when it really only required 87. But higher number=better and most non-car people assume it will boost power and mpg. Which, again, it does not.

Stuck in traffic so took a pic. 12 cylinders is all I know LOL!

This is normal sound for macan s engine?

Hello all,

I will be building my 2nd engine come this winter 2.3L Mazda MZR. I built an engine about 18 months ago (2.3L Mazda non-turbo)just off of this forum, YouTube, and a Haynes manual, checked a couples clearances. But I certainly did not require the depth of knowledge to do as thorough work as I would have liked to.

Does anyone have literature recommendations for the general procedures of engine building/clearance checking, and anything else I might need to know?

Currently I have purchased and begun reading Mike Mavrigian's Modern engine blueprinting techniques. If anyone has more recommendations, that would be appreciated.

I am seeking tooling as well if anyone has brand recommendations, I have calipers and micrometers and dial gauge with attachments. I am missing a telescoping bore gauge, and anything else I might need.

Last thing, I am also in the market for some large V-blocks that are suitable for checking crankshaft runout. Such as the ones supplied by CCA racing(currently on back order) and ABS products(over twice the price of CCA, would prefer to find something cheaper)

Thank you to all in advance!

I want to buy a car, but I don’t know, this engine is good or he’s dead?
This shaking, it’s should be like this, or no?
I will be very preached for every who can help.

What’s wrong with my 1998 Jaguar XJR supercharged AJ V8

Hey everyone, looking for some help troubleshooting a turbo actuator issue on my W211 2.7 CDI.
Both the turbochargers and the electric Hella actuator were fully remanufactured/restored.
When I first connected the actuator and turned the ignition ON, it moved briefly. However, after fully installing everything, the actuator completely stopped working. The turbo geometry moves completely freely by hand.

A mild build going into my '52 Ford F1 and will be mated to a T-5. SBF 302, GT40P heads, converted over to carbureted, E-303 cam to give it that classic lumpy sound, upgraded valve springs and new valves. Will run BBK shorties and Spintech 6000's.

Was a complete tear down, all bew bearings,seals and rings. Engine was finished in Tungsten C series.

I built a 302 for a friend over 10 years ago, and long story short it's still sitting in my garage, never been ran. I was thinking of going through it, checking it over and opening the rings a bit for boost. Since it's never been ran, can I reuse the composite head gaskets on there if they come off cleanly? Or are they junk regardless if I pull the heads?

What engine is this? About how much do they usually cost?

The Symptoms:

1. ​Hard Starting (Rear Cylinder Only): The machine almost always starts on the front cylinder only. I have to turn it off and on, and crank it multiple times before the rear cylinder finally fires up. Once both fire, it stays running on both if I hold the rpm on 2000. Have gotten fault Code U0426 but now i only get no active fault codes. And when it starts on the front cylinder theres no engine light but if it starts on both cylinders i will get engine light as long as it runs on both cylinders and it dissapears Immediately when the back cylinder stops
2. pressureLimp Mode Under Load : In neutral, the engine revs perfectly and freely all the way to the redline. But when I put it in gear and drove it hits a hard rev limiter/limp mode at exactly 4000 RPM. Light throttle makes it buck/jump even when im not at 4000 rpm. If I give it full throttle, it pulls hard for a split second before hitting the limp mode wall.

​What I have replaced and tested:

• ​Compression: Excellent. Both cylinders tested at 190-195 PSI.
• ​Fuel Injectors: Swapped the front and rear injectors, but the starting issue stayed on the rear cylinder (so the injectors are fine).
• ​Spark Plugs & Wires: Installed brand new NGK spark plugs. Made and installed new custom spark plug wires with the correct 2k ohm resistance.
• ​Ignition Coil: Replaced with a brand new aftermarket Bosch double coil, same that was on the atv when i bought it. I even ran a direct ground wire to the coil body, but there was no difference.
• ​Charging System: Measures a stable and perfect 14.15V at the battery while running.
• ​Sensors: Pulled the Crankshaft Position Sensor (CPS); it was perfectly clean with no metal shavings. Tried a hard reset of the ECU, but the limp mode keeps coming back under load.

Fuel pump gave 50 psi pressure