View Full Version : Distributor Question
05-08-2010, 03:07 PM
I'm running an msd distributor with a 604 crate motor. Can anybody help to determine correct timing curve in distributor or should it just be locked at full advance? Thanks in advance for any information!!!
05-08-2010, 04:12 PM
The timing curve on any race engine is ultra critical to how it accelerates, and is even more critical on a crate than any other engine. I always run my personal stuff unlocked and I can tune the curve that way. Yea you can throw a spring or a weight but in 25 years I have been very lucky and have never done it, and that includes 9500 - 10,200 qualifying runs with ARCA SB-2's.
We were one of the couple teams that caused ARCA to implement the rev-limiters. When you get an SB-2 up in that range it is like pulling a 5th gear that is not there, although a couple times it was there until they outlawed that too...we just went to 3 speed with a 4th as overdrive. It pays to know Jerry-co.
Anyway back to you question, along with matching this to the fuel curve I find this to be one of the biggest gains you can accomplish on the chassis dyno. We have seen average gains 20-30HP and 50ft/# TQ on getting both ignition and fuel curves matched to each other. I have customer that run locked cause they belive in it and they are just losing bottom end torque, and no my timing curves are not all in at 2500rpm's like most. We have been doing distrinutor work for 25 years, if you can't find it done locally, you can pm me and send it on. Ideally we get your carb and spark plugs and wires and fuel you use to get everything kosher. We slap that stuff in our crate mule and let it eat. As long as you engine is not wore slap out she will kick like a mule when you get the stuff back, at the same time we can also evaluate your Carb and let you know how it stacks up. You will find that once you optimize you ignition system all of the additional thing you do will make way more power.
When I quote numbers on here people freak out, well there is reason an oil filter can make 11hp, and an air filter 14hp and oil 17hp and plugs 21hp. The capacity of most crate engines is about 450hp when you get the Karma just right you will start seeing the needle get close to 500 and when you then play with the oxygenated fuel you'll see well over that number.
I have been working on a Legal 604 that will fall under evey rule, Fastrak Ne-Smith and ASA, that we want to run road racing and hoping to hit 600hp with a carburetor. We have been close with fuel injection and if I get some more time to play with it we should be able to hit it by the big fall weekend at Road Atlanta, I know it is wine and cheese trophy racing but it is still racing and the TQ and HP really shows off on a road course, cause you got 5 or 6 speeds and 175+mph in a Late Model.
It is kinda like matching the burn speed of the fuel you are using to the fire source you are feeding the engine. Spark plugs also play a huge factor in this and if the heat range and fiiring speed is not up to what you ignition, and fuel want you can also be losing out. Matching up the plugs is usually about 5-10hp.
That is the stuff I have been working on for almost 10 years on crates, from the inception of Katech running them road racing, then ASA running the Corvette Crate and then the inception of the 604 in ASA pavement racing to Fastrak running the 604's on dirt. You have to identify the limiting factors, come up with something to make it better and then prove it on the dyno and the track and then the engines run like real race engines.
I consider crates to be like Cup Plate engines, not because they are air limited from the restrictor plate, but they have so many other limitations that need to be overcome.
05-08-2010, 07:26 PM
Oil filters, oil, air filters do not MAKE hp they free it up. Some one with your vast knowledge base should be able to get your terminology correct!
05-08-2010, 08:42 PM
So....what is the difference between "making" and "freeing up" horsepower then?
05-09-2010, 07:27 AM
An engine can only make XXX hp. Changing a cam MAKES Hp, Increasing compression Makes hp, Changing your oil filter, oil pump, oil, will only free up an existing quantity that is already there.
Dyno constantly claims that his water pumps MAKE hp on the dyno If that was the case then you could dyno the engine without a water pump and get a base and then put his pump on and it would have more than without it. It is not going to happen.
Most of us who visit here understand that the horsepower and torque available to the rear wheels has increased. How he accomplishes it does not matter to those of us who REALLY race. All we want to know is how to duplicate the results. If the use of the english language is really that important to you I suggest maybe a grammar forum of some kind.
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