I told you it would put out some serious torque, gotta love that end of it. I hope the 30 over works out for ya.
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I told you it would put out some serious torque, gotta love that end of it. I hope the 30 over works out for ya.
.030 will work, ordered the piston yesterday, and hopefully will have it back together by next weekend. i am still kind of surprised how much more fuel this intake requires.
Charlie, you gotta consider your allowing the motor to flow approx 3X more air than with a horn or downdraft......... Same situation I've run into....."Needs More Fuel".Quote:
Originally Posted by mrcrsr
Glad to hear .03 will get you back up and running.
I have a hard time believing that it's really 3x the air. I think that the reed blocks are a restriction.
I agree. It surely allows more airflow, but the reed blocks are now the bottle neck.Quote:
Originally Posted by Todd D
Correct on 3X the air, that's why I said "Approx"......LOL.Quote:
Originally Posted by Todd D
I had it figured out at one time by calculating the total sq in opening in the down draft vs the 3 horn MAD and it was better than 2.5X the size. You are also correct in stating that the reeds are the restriction, but you also have to consider that it's "Vacuum" and not pressure that's sucking in the air and vacuum is a very powerful force that can over come restrictions to a point more so than pressure. All I can tell you is that running the motor till it dead heads at 85 MPH with the cowl off and using a spray bottle, spraying fuel into the horns it picks up and goes for that instant of the extra fuel sprayed, that's a fact.
Charlie are you going to just raise the ports or change roof angles too?
At the rpm it was at not up to the point of the Reed cages being a restriction. Torque output was definitely up, and the modified cages in this engine flow a lil more then 10% over what the stock 300x cages flow.
A
ported the engine a lil further, had the one hole punched .030, have new piston on hand. if figured while it was apart i might as well rering it. took all the rings off, put the pistons in the parts washer and as i was bring ing them back to the bench a locating pin fell out in my hand! i guess maybe it was a good thing this motor came apart when it did. i checked all the pistons and it looks like there maybe 1 more with a loose pin. thing only had 250 hours on the pistons! i'm ordering a new set today.
Any pics of porting/stuffing etc you've done? :)
Who made the pistons? Forged or cast?Quote:
Originally Posted by mrcrsr
Dave
They are vertex
Good thing you found the loose pins. So all new piston now?
Dave
I guess at this point the pistons are a 250 hour change out part. Ordered another set of vertex. My machinist said he could top pin a set but what would I do for rings? He can modify the rings but I need a set that don't have grooves cut in them so we can groove them after the fact. Wiseco pistons were suggested but I've never had good luck with them in a mercury but supposedly the pins don't come loose.
Ha Ha the Wiseco thing, some like them some not. I have had good luck myself, always done the full heat soak thing at least 6 times when new and had good luck. A buddy told me the newer ones tend to expand less the first few runs and let you run them a bit tighter from day one without the worry of seizure. I don't know but he builds a ton of 2 strokes.Quote:
Originally Posted by mrcrsr
To each his own, Best of Luck Next go around.
Dave