super tunning..... timing vs compression

[Michael J Giesler]

I have seen champ motors and drags with timing on max advanced they still turned 10k+ with no problem there are a ton of factors attitude how lite the boat is how big the prop is yada yada I liked my dads idea if you have a lot of money run it till you stick a piston turn it up two clicks and your good to go lol

[Wayne Arnold]

I don't have a lot of money but I guess that's what I did. Just stuck #6 with timing at 28 degrees, 150# compression and ACU leaned down some. Rebuilding and will make adjustments. Man it sure was quick up to that point. Have to know the out come when you make adjustments.
Been running like this all summer finally got the wrong fuel.

[woundedwarrior]

Man your making me crenge Wayne ....Im fixing to bolt on 160 lb heads ...but I have a stock box and its not that lean...I'm gonna experiment with xylene and toluene for added octane on top of 93..Guess I'll start timming at 23 deg. And work my way up..watching the plugs .She is a good low hour mercury built stocker other than the heads and oil injection and timing module removed...I usually run Pennzoil Full syn. At 40:1 But I miss the smell of klotz so I just picked up a $48 jug of super techniplate on an impulse at the cycle shop ..So I can always blame it on that lol...If I keep her I was planning on cutting her guts out this fall anyway and put good metal cauge bearings and good stuff in and just keep the revs under 8k but see how much power can be made from a laser injected Promax mota....So if she goes no biggie..It will just give me a starting point

[dwilfong]

"burn rate" advancing the timing starts the burn earlier. Higher compression will do the same.
Burn rate understand it and you will find power.

[Slimm]

Toluene is almost $17 per gallon here in Danville. I used to get it for about $3 per gallon in the late 80's-early 90's. I would love to try some to boost octane but that is just cost prohibitive.

Slimm

[olboatman]

Scribed--- Very Interesting! Gary

[RBT]

Laughing @RBT........

No Guts, No Glory......

Glad you like it.
These threads kill me.

[dwilfong]

Propylene oxide will increase the burn rate of fuel. You will not have to advance the timing as much at high RPM. Also you do not have to run as much compression as this take power to compress the mix.
That with Klotz KL-100 makes a great mix.
You can put more fuel in the chamber and lite it off as it will burn quicker and the Castor in the KL-100 will keep the chamber temps lower. Castor also migrates to heat not away from heat as synthetic oil will.

[johnboy 88 vegas]

Man your making me crenge Wayne ....Im fixing to bolt on 160 lb heads ...but I have a stock box and its not that lean...I'm gonna experiment with xylene and toluene for added octane on top of 93..Guess I'll start timming at 23 deg. And work my way up..watching the plugs .She is a good low hour mercury built stocker other than the heads and oil injection and timing module removed...I usually run Pennzoil Full syn. At 40:1 But I miss the smell of klotz so I just picked up a $48 jug of super techniplate on an impulse at the cycle shop ..So I can always blame it on that lol...If I keep her I was planning on cutting her guts out this fall anyway and put good metal cauge bearings and good stuff in and just keep the revs under 8k but see how much power can be made from a laser injected Promax mota....So if she goes no biggie..It will just give me a starting point

The last 2.5 carb steel motor I built (half a**ed) for my Vegas started out at 150 lbs on all cylinders with new rings and sorry scuffed up bores....stock 2.0 heads with the thin .75 head gaskets. Btw on a 2.5 there is exactly 10 lbs difference on compression between the .75 and 1.25 thickness head gaskets....cheap power. After about a year I checked the compression again and they were all up to 160 lbs (I suppose the rings finally found their happy place in the grooved steel). I was running 25* of timing, 7 petal 260 reed blocks, drag cut exaust chest, WMV carbs with standard premium pump gas and this motor ran like a raped ape off the line to over 7k. Needless to say it finally ended up scuffing #3 at random probably b/c of me running 1/4" washers instead of 1/8" or stats. If you want to have fun with compression just try it on a cheap wore out motor first so you can get a feel for tuning it instead of ruining a $8K powerhead the first time out.

[lokinutz]

"burn rate" advancing the timing starts the burn earlier. Higher compression will do the same.
Burn rate understand it and you will find power.

How does increasing compression start the burn earlier, unless we are speaking about a diesel?

[powerabout]

Does the better designed engine make hp with less timing?
(Assuming we are not talking 20,000rpm)

[dwilfong]

Let me rephrases that. advancing the timing will start the burn earlier to compensate for the lower burn rate. compression will increase the burn rate of the fuel.

[ChrisCarsonMarine]

Put things into proper perspective... The fuel/air mix will burn at the same rate if compression and temperature are the same,however the motor runs at different speeds.it idles with the burn started at or near top dead center,but as the speed increases the piston quickly outruns the burn rate,and the power is lost...burning in the exhaust.So,we light the fire before top dead ? degrees so as to get the best push,but too soon will basicly try to back up the piston...detonation.So,many factors are involved...especially operating rpm,Chris

[Lockjaw]

On my motor, I believe it runs better with max timing at 18 versus spec of 20. So my money would be on compression adding more power.

[powerabout]

On my motor, I believe it runs better with max timing at 18 versus spec of 20. So my money would be on compression adding more power.

what engine is that?