Cranking compression results are in

[Art]

It's a "my dad can whip your dad" contest, or "my Johnson is bigger than yours". It's a schoolyard thing.

Or its a guy who just parrots the same stuff magazines published 25 years ago, vs people who actually work at engine shops with a real dyno/flowbench and know how to get more NA power out of stuff that was already making 3hp/ci without increasing the rpm. a lot of very knowledgeable guys have stopped posting over the years because of the ones who still think the earth is flat.

Who cares? People can post what they want, can't they? Not everything on the internet is taken as gospel, I hope.

[cab0154]

It's a "my dad can whip your dad" contest, or "my Johnson is bigger than yours". It's a schoolyard thing.

Or its a guy who just parrots the same stuff magazines published 25 years ago, vs people who actually work at engine shops with a real dyno/flowbench and know how to get more NA power out of stuff that was already making 3hp/ci without increasing the rpm. a lot of very knowledgeable guys have stopped posting over the years because of the ones who still think the earth is flat.

Who cares? People can post what they want, can't they? Not everything on the internet is taken as gospel, I hope.

Some of us who have been here and have learned a lot from those in professional motorsports (people who couldve otherwise been spending time making $ with the knowledge) that used to post, would prefer if it were still a place to exchange new ideas and advancements. but I guess some people are happy do otherwise. good to know where people stand.

[Tuner]

Have you noticed $tupid $hit is never constipated?

[Art]

I just assumed, apparently falsely, that everyone has a right to his opinion and that the reader could sort out the differences.

[Tuner]

The falsehood is stating opinion in the guise of fact. It is misleading to the uninformed who seek fact based information and unfair those whose reason to ask a question is because of not having enough experience to sort fact from opinion.

[SilverChicken]

Meanwhile, back on topic…

[ClassAct]

Meanwhile, back on topic…

Back on topic...I run 12:1 on pump gas with iron heads. A

ll things claimed to be wrong. There is a process to follow doing higher than "orthodox" compression ratios on pump gas. You absolutely MUST use a timing CURVE. You also need to control coolant temps. I know that thermodynamically that's a bad policy but it's my OPINION that what power I lost with the cooler temps (if in fact cooler temps make less power but I digress) I more than gained back with what I consider "standard" timing.

Also, I have struggle with some people who think that reducing timing is bad. It's not. If I can run more compression and I have to reduce timing who cares??? You are reducing pumping loss. That's a good thing.

Running more compression is like adding a power adder. The combustion chamber is packed tighter so it NEEDS LESS timing, yet people talk like you just dropped 50 HP by taking 2 degrees of timing out.

It's great to have an opinion but what's bad is repeating error over and over and over and over like it's fact.


IMO, building a street/strip with less than 11:1 is leaving power and drivability on the table.

But, if you believe the orthodoxy you end up building than you can tune for and then they claim it can't be done.

And BTW I'm not saying you as in YOU but in general terms.

[F-BIRD'88]

QUOTE: "Under load would be DIFFERENT"

No shit, Sherlock. You're a real piece of work.

[ClassAct]

QUOTE: "Under load would be DIFFERENT"

No shit, Sherlock. You're a real piece of work.

Read closer. He said he could do that with over 17:1 and not have it rattle. No one with the IQ of a fruit loop would build a pump gas engine like that. You can do it but you can't get to WOT.

Like I posted above, reducing timing isn't a bad thing. It's a good thing.

[F-BIRD'88]

Meanwhile, back on topic…

Back on topic...I run 12:1 on pump gas with iron heads. A

ll things claimed to be wrong. There is a process to follow doing higher than "orthodox" compression ratios on pump gas. You absolutely MUST use a timing CURVE. You also need to control coolant temps. I know that thermodynamically that's a bad policy but it's my OPINION that what power I lost with the cooler temps (if in fact cooler temps make less power but I digress) I more than gained back with what I consider "standard" timing.

Also, I have struggle with some people who think that reducing timing is bad. It's not. If I can run more compression and I have to reduce timing who cares??? You are reducing pumping loss. That's a good thing.


Running more compression is like adding a power adder. The combustion chamber is packed tighter so it NEEDS LESS timing, yet people talk like you just dropped 50 HP by taking 2 degrees of timing out.

It's great to have an opinion but what's bad is repeating error over and over and over and over like it's fact.


IMO, building a street/strip with less than 11:1 is leaving power and drivability on the table.

But, if you believe the orthodoxy you end up building than you can tune for and then they claim it can't be done.

And BTW I'm not saying you as in YOU but in general terms.

I have done jsut this also. Ran 12.65:1 on pump gas with retarded spark timing (27deg).
Kept off the throttle if when temps over 180F. Reduced power output.
When ran on 110 Octane unleaded and correct WOT timing (36F) The engine is MUCH happier.
MORE more horsepower and torque and throttle response.

On the street in the real world driving conditions you cannot hold the (Air inlet and Water temps) temps under that tight control.

Your luck will run out. Water-methanol injection is a viable method alternative to high octane gas.

[F-BIRD'88]

QUOTE: "Under load would be DIFFERENT"

No shit, Sherlock. You're a real piece of work.

Read closer. He said he could do that with over 17:1 and not have it rattle. No one with the IQ of a fruit loop would build a pump gas engine like that. You can do it but you can't get to WOT.

Like I posted above, reducing timing isn't a bad thing. It's a good thing.

When I drive my car I like to go beyond idle throttle opening.
In a drag race it is customary to run at WOT for 1/4 mile.

The foolishness is really getting sickning

[Dave B]

Everyone can state their opinion. But all kinds of guys push the envelope daily. So it's crazy to not call out people that constantly rattle on about old ideas that are way past the truth of today's progress. The factory cars and motorcycles are above compression ratios that was deemed crazy 25 yrs ago. I did take it out on f bird tday, but their are several people on this site that know dcr and a certain "compression" means nothing in a dynamic state in all instances. I don't know everything and never will but I never focus on crap I hurd or read ,I test and test and test. If something bites me hard, I don't quit either. I look at it from different approaches.

[Dave B]

20240319_183836.jpg

20240319_183522.jpg

So f bird since the whole world is seeking your race skills and all out knowledge of everything what did you build tday? This is what I worked on . Anti reversion plates on 1700 plus hp na engine

[cab0154]

There are current production engines, in street cars running 13:1 on 87, at WOT...so a lot has changed. Those same engines do pick up power on 93. But if you are expecting old stuff to run more compression on 93 than we did 25 years ago, your setup won't be the same as it was 25 years ago. But not only is it possible, it's common place and these days and is being done while under warranty....with coolant Temps between 210-220*. No water meth injection. The world is no longer flat.

[SilverChicken]

Well I think this is a go. Finally got the tuner to respond and he said the compression isn’t an issue as long as I can keep 93 in the tank (already did) and run a 160 t-stat. I think I might pick up a 2-row radiator too with 1” cores. If anything it’ll help keep the temps more stable even if not lower. I’ll run a step cooler plug too. Thanks for the input fellas. I was kinda hoping AlkyIROC would come in here and respond but I got mostly what I was looking for.