? Mech Injection/gas

[DEL51]

My buddy sent out his crower stack injection to have it dialed in at Kinsler.They want to know alot of details and one of them is head data.He has the 350cc Canfields and he cleaned up the ports.These were bare castings, had to have all the machinig done locally.I believe his port job was nothing too extravagant. That said,how critical is this information??Should he have the head flow tested? Could he use the canfield flow numbers from the as supplied "ready to run" 350 cc head? This is for a 540 BB chev with a 650 lift/264 dur @ 50, 10.25 comp.premium pump gas engine.This is for a lake boat,Southwind tunnel.Thanks.

[Moneypitt]

I think the real #s from the 2.9 crowlers is 1300 cfm. We run them on the PS boat, and used with the "old school" cast iron heads they' re hard to beat. With the CFM #s of later years, they are probably a little on the "light" side of the flow capabilities of the 21st century heads................I'm still planing on using them on the short stroke PS motor, with the cast iron heads, although the heads of today will find them lacking in flow............MP

[GofastRacer]

Yes the more info you can supply the closer they can set it up, but they can only go by what you give them, if you modify the heads then the "out of the box" numbers are out to lunch, you need to flow them after modifications and give them the specs then they will set it up accordingly!.. BTW, I do believe all ports flow equal on those heads so don't use the staggered stacks!..

[DEL51]

John is using the even stacks. He is def and I started this thread on his behalf without his knowledge in hopes of gaining some insight and helping him out.You guys have been great. I, and his son have been in betweeners regarding kinsler.Take no pity on John, he is an Accomplished race boat driver. He is used to running alcocchol injection, I am info man along with his son. Hopefully we can convince john to flow the heads,but your input is important.Thanks,Chris

[GofastRacer]

You could give them the stock numbers it will run, it won't be as close so you may have to do a little more fine tuning, not that big of a deal!..

[Unchained]

I've been reading a book on engine management systems, better late than never.
I just wanted to point out the fine tuning line that's required to get the mixture right with EFI or MFI on gasoline.
With an EFI system at idle or cruising speed my injectors are firing at 1.75 milliseconds per revolution.
That's not much fuel. Just a small fraction of a drop per revolution / per injector.
If I increase the injector timing to 1.85 milliseconds that's too rich and if I decrease it to 1.6 it's too lean and won't idle good.
With mechanical injection if your injectors are all flowing, all the time, the amount of fuel that comes out of them would have to be a very, very, fine mist to be correct. Metering would have to be so fine that temperature would affect it.
To get it right would be a real challenge.
That's probably why Kinsler needs some very specific info on the head porting just to get it in the ball park.
Tuning with alcohol would be a much wider tuning range because of the mixture ratio but, "it takes 2 1/2 times the amount of alcohol to match the HP you get with gas".
Guess who I quoted that from ?

[Fiat48]

My buddy sent out his crower stack injection to have it dialed in at Kinsler.They want to know alot of details and one of them is head data.He has the 350cc Canfields and he cleaned up the ports.These were bare castings, had to have all the machinig done locally.I believe his port job was nothing too extravagant. That said,how critical is this information??Should he have the head flow tested? Could he use the canfield flow numbers from the as supplied "ready to run" 350 cc head? This is for a 540 BB chev with a 650 lift/264 dur @ 50, 10.25 comp.premium pump gas engine.This is for a lake boat,Southwind tunnel.Thanks.
Kinsler is just trying to get the fuel curve for your application as close as possible. That's why asking for flow numbers. Out of the box flow numbers from Canfield will be adequate. Kinsler will have you a little fat anyway.