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Porting cyls w/ racelogic template and 4mil short rod


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i dont see a problem with new guys using templates. gives them a chance to practice without totally screwing up something. but the problem is the template was probly intended for stock stroke and bore. with the added stroke its gonna throw a curve ball in the situation. if you dont have the knowledge to sort it out i would get some help before you start cutting

 

x2, using someone elses design will get you somewhere but just "tracing" will get you nowhere. Transfer ports, boost ports and port angles are all things usually not found in templates. Everyone needs to start somewhere but to go above and beyond you will need to broaden your knowledge of what you are actually doing to help your engine function the way you want it to.

 

I have a few templates laying around that I have drawn up for us to try on some stock cylinder setups. They have intake and exhaust shapes already layed out, but on the back of them you will find information on port timings, transfer timings and shape, and boost port shape as well as all of the angles complimenting them. It is a process and will be a method of trial and error...dialing in a good port job is expensive. Hardly worth it if you are not in the business, but a nicely done home port job can be very cost effective and rewarding. Don't be discouraged, just read more, get a better understanding and give it a try. Worst case scenario you will have to buy new cylinders and send them to a builder.

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Take your time dont rush and dont get discouraged another tip , dont do one jug then try n match other I use the same toll as long as I can on both jugs . Like ill both intakes at same time same tool then switch tool and do both intakes with that it saves time and keeps everything on plain with each other

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Damn, usually a bunch of Negative Nancies when someone wants to port a cyl. Even have a site sponser being positive. Though you might not achieve Dick Measuring Dyno numbers, don't be discouraged.

As Young Gun mentioned, those templates make the intake bridge to narrow for my comfort too.

A search will/should show timings relative to port styles, ie, drag, dune, trail, etc.

 

Besides McDizzy site, Gorden Jennings and H. Grahmn Bell, along with available comp programs for port timings, etc..

 

Pasi S. and another from Saudi, (or somewhere middle east) have sucessifully done own porting (most recently) and have some pics, etc.

 

Good luck and let us know how it goes.

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Here's what I got so far, measured with 0.020" base gasket, Vito's superstock pistons, 58mm stroke, and 110mm rods. The pistons are stock height Wiseco that are notched roughly 0.045" (1.14mm)  to change the port timing for the exhaust. I will be using regular Wisecos for the build. Here's some other possibly useful info: I have new V Force 4 reeds, 28mm Mikunis, and Pro Circuit Pipes

 

All measurements include the piston pop-up distance.

Degree measurements for the exhaust measured with piston notch.

 

Piston Pop-up = 2.08mm  @ TDC 0°

Top of exhaust = 31.55mm @ 84°

Top of transfers = 46mm @ 117.5°

Bottom of exhaust = 55.07mm @ 150°

Bottom of transfers = 56.69mm @ 161.5°

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I plan to work the transfers. I've got a straight and 90° pencil grinders with all the bits. I want to pick up some extended 1/8" bits to get up in the transfers. I do some tool and die work, so I have access to about anything revolving around grinding and polishing.

 

I plan to leave the cylinders at stock height with stock base gaskets. I picked up a Pro Design cool head, and plan to turn the domes to accept the extra 2mil of piston sticking out of the deck.

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I always grind the exh floor in a way to aid the ring in coming back in cyl , there is more to it than measurements I gave the op some measurements as a guidline

but what transpires in the tunnels and behind the sleeves is what matters, just remember when starting out less is more

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