Ever wonder how much difference a port job makes?

[callison]

Reg and green lines (lower) are flow rates before the port job, the upper lines are after, and there is no "Best V11" baseline on the plot, that's just part of the program text for the computer graphics.

 

 

Someday I'm going to actually put these heads back on the bike.

[gthyni]

Flowbench or not?

This guy has an alternative view

[jrt]

Uh, now I'm confused. I can't read the legend on the graph- are the red/green lines pre-porting, and the blue lines post-port throughput? <_>

And is there a line for 'best stock v11'?

 

cheers,

Jason

[callison]

About that "Alternative View", I'll just leave it to the people with experience and not try to improve my hardware with verbage. There are simply too many variables in improving engine performance to be as didactic as this guy. Pick your tuner based upon his experience and track record. The Guzzi LSR bikes sported RaceCo ported heads the first year. They went fast. The second year, the same head ported by Mike Rich. They went much faster. There's always much more to it than that, but there is definitely an advantage to having someone that is really good at his craft involved.

[dlaing]

Someday I'm going to actually put these heads back on the bike.

Hurry up now!

We want to see before and after dyno results.

You did do a a before dyno test, right?

No? Oh, well. In any case it looks like Mike Rich pulled a couple of dead rats out of the ports!

[Guest captain nemo]

Goran,

 

That article is excellent! I know nothing about motors as I unabashedly demonstrate daily on this forum, but I am also an 'out of the box' thinker and I like this guy's train of thought and creative analysis. Boy, this could lead to big fights! What he is saying sounds like blaspheme, but I think there is something to it. I was wondering about simply dumping the air box like I did to put on pods. There are so many factors to simply think that "more air is better." Is the air turbulent? I always wear Polaroid glasses because they 'straighten out' all the turbulent light rays. I am sure a cylinder head would like to see 'polarized air' also. Etc. etc.

 

(As an aside, I also liked what he was saying about smooth power delivery and its relation to cornering - that's where I think its at also.)

 

 

It makes me wonder about my tappet adjustment job this weekend. I really like how the Guzz is running right now , and I will bet that my clearances are at minimal gap adjustments. We'll see.

[gthyni]

Most experience porters are autodidacts or have learned

by working with people who knows this stuff,

there is no university of motor tuning.

 

There are many examples where traditional "flow porting"

has worked very well, but there are examples here

in Scandinavia both in road-racing and drag-racing

where Motoman's "velocity porting" have been used

with great results.

[al_roethlisberger]

I'm with Carl on this point. It sounds like the writer of the article is well-informed, but from my conversations with Mike Rich, his approach isn't as simplified as maximizing CFM flow. I got the distinct impression that he considered several other factors, including many of the points the writer makes to produce the desired end-result.

 

I was going to scan my results from Mike, but I just found them and they look so similar to Carl's that there's no point. I also found the results of Mike's work on my heads regaring flow, etc and quoted it below.

 

Bottom line though, as Carl mentions, I trust Mike's experience providing the LSR bikes and others, successful equipment

 

I'm very interested in his new pistons

 

al

 

P.S.

 

Also, on a related note, I sent Mike Rich a question about the FBF "large valve" kit, and here was his response. This goes toward the argument that Mike seems quite aware that "big is not always better" and depending on one's goals(street vs. track, etc) *tuning* to that goal is more important than purely increasing flow.

 

 

YOU HAVE 47MM INLET  39.5 MM EX VALVES - THE DIFFERENCE IN FLOW THROUGH OUT ALL LIFT RANGES BETWEEN THE 40MM(FBF "big valve")  AND 39.5 MM EXHAUST IS A BIG FAT ZERO - ON THE GUZZI EX - BACK SHAPE HAS MORE TO DO WITH FLOW THAN THE .5MM DIAMETER INCREASE

 

 

 

P.P.S.

 

Here is what Mike delivered with my head-work:

 

 

Well, Mike got my heads finished, and they are on their way back to Moto Italiano... here's his report:

 

He is continually "impressed"(sarcasm alert! ) by the lack of consistency and quality of Guzzi parts I think. His words were, "...offically, these were the worst heads[Guzzi] ever..." and it took him an extra three days or so to be able to wrangle the right flow out of them that he was aiming for.

 

He was joking that they must have put an apprentice on my heads as there was so much taken out of the port by the factory that it was nearly impossible to machine it properly. Further, when he dual-plugged the head, casting inconsistencies have proven to make it impossible for him to standardize on a single repeatable process and to have any reasonalby consistent expectations. He makes it work just fine, but each set is a new adventure apparently.

 

Anyway, the good news...

 

He got about 126CFM(125.4/125.7) out of my intake side, from a stock 112 approximately. And the exhausts came out at about 82-84 CFM. The intakes were at the bottom of average(referencing his difficulties porting them above) while the exhausts were on the high side of average for his "Stage II" effort. But then again, he has historically only gotten at best around 130CFM even for "Stage III" race-application porting on the intake side, so it's not a major difference. Plus he said you won't feel the difference between 125 and 130 CFM, but from 112 to 125 CFM will prove a distinct improvement mid-range.

 

He says the general rule-of-thumb is .43HP per CFM gained on the intake. So in general, so we're looking at about 5.8HP potentially from each side, gross. Who knows though. The dyno, and other dependencies will make the final impact and report

 

[Guest Jeff Kelland]

I just took a look at the "motorman" site. He seems to want to take credit for a lot of "new" information that in reality is pretty common knowledge. It really depends on the original head design whether you would want to make ports smaller or larger. Prostock car racers in the '70's running Ford cleveland heads had to reduce the port size to increase flow velocity, let see... that's 30+ years ago. When I did a cylinder head for 1 of My friends GS1100 Suzuki dragbike, I really opened up the ports to see what happened (we're poor guys, no flow bench). we gained a 10th and a half and 4 mph (9.38 and 144mph). I paid the legendary Jerry Branch to do a set of HD XR1000 heads 15 years ago and with cams, carbs, compression, and pipes, gained over 25% in horsepower. I think most of the well known head people probably know all about what motorman has "discovered". A flow bench is just a tool, experience and knowledge count for a lot.

 

 

 

 

 

For

[Guest northend]

May I ask how much Mike charges for a street port job? Including valves, I heard that he says the stock valves are soft.

[al_roethlisberger]

Please don't quote me, as my memory is poor a year later, and the quote below is also dated a year ago but at that time....

 

From the Anyone dual-plug a V11? thread:

 

 

His pricing is about $700 for "Stage I" which is just the porting, and $800 for the "Stage II". There is a "Stage III" which is $1300, but I forget what all it entailed, and he said it was geared for a race application, not what I was looking for.

 

 

I think by the time I had my valves replaced, and had the heads dual-plugged, it was about $1400

 

Also from the "dual-plug" thread:

 

 

I just got off the phone with Mike Rich today, and after everything is done, the total will be about $1350. Because of some issues with the valves, it's about $200 more than the initial quote.

 

So here are two issues to keep in mind:

 

1) Remember to have the shop send your intake manifolds to him 

 

He didn't mention that to me when we were going to ship the heads, but I guess, ummmm "duh" My fault there  No big deal though. He said the porting was one of the last things in the process, so if I ship him the intakes "3 day" that should work out just fine

 

2) Apparently MG has used relatively soft valves in our bikes, and had a rather sharp guide. Mike has noticed(and warned me ahead of time) that the OEM valves he's received have worn significantly over relatively minimal mileage. He's seen bikes with 5000 miles with .005 wear, and the guides worn similarly. This is caused by the lateral forces on the valve-stem from the rocker, the guide having a very sharp top edge, and the softness of the valves. He tested the valves and consistently find them to have a "Rockwell-c" hardness of 29.5-30, where in his opinion they should be at least 35.

 

My valves' stems were worn .002 with only about 3000 miles on the clock. While not a big deal yet, one can extrapolate that as this wear gets worse, it will only accelerate, and then the guide and even the boss that the guide fits into will wear out. Result?... oil burning, poor valve-train performance, binding, etc...

 

So, the moral of this story? Keep an eye on the wear of your valve stems and guides, and if you have a chance to change them to a better set, you may want to take that opportunity. Because Mike says every late model Guzzi he's worked on has this valve wear issue.

 

BTW, this added another $160(~$38 per valve) to my bill, as he's installing Rockwell-c Hardness 38, and nitrile coated valves to mine. They should slide easier and last "forever"... more or less

 

I should have the heads back in a week or two at this point 

 

al

 

 

 

But just give Mike Rich a call at the following number, and he'll be happy to explain the benefits of his different services. He's very honest about what is appropriate for one's needs, and doesn't try to sell you on something you don't need, which I really appreciated

 

MIKE RICH MOTORSPORTS

21 JERUSALEM HOLLOW ROAD

MANORVILLE, NEW YORK. 11949

FOR TECHNICAL ASSISTANCE DIAL:(631)874-7032

 

And for some info on the applicaiton of his work: http://www.cookedgoose.org/

 

al

[callison]

The additional damage from the sloppy valve stems and loose rocker bushings brought my total to $1610. I sent the heads in in April and got them back in late September. Mike is one busy guy. He has to lose a lot of time just to phone calls from customers though as he likes to explain in detail and shoot the breeze as well. He loves Guzzi owners, we're very patient. Probably something learned from dealing with MGNA while waiting for parts...

[Guest russ]

Speaking of port jobs, I knew a girl once in Dalas....... er, oh we are talking bikes here. Back to the point, I had a local guy here port my beemerairhead a few years ago. Biggest difference was the smootger and more linear acceleration. Worth alot but I paid less than the $700, $400 seems right by my foggy memory. Must be too many visits to that girl in Dallas.

[Murray]

Would be intrested in seeing what actuly difference (ie on the Dyno) These mods make. It was suggested to me that while there are some improvments to be had by porting Guzzis there are fairly modest as the Guzzi ports are pretty striaght very short and there is still only two valves in the combustion chamber. This was from a fairly experince Ducati tuner that did a lot of pot and flow jobs mainly from racing athough I don't think he actually used a flow bench. There would obiously be a piont where you are restricting the flow if you went too small.

[Guest captain nemo]

Just as a related aside, I just picked up a magazine called 'Italianbike' which is excellent. There is a small article on the MGS/01 (of course, it's in all the magazines). But I noticed a detail I did not see in other articles. It said the gas was housed in the upper frame members and that the 'gas tank' was really a cover for the HUGE 18.5 liter air box! I suppose the reason many, if not all, of us have made changes with our own V11 airboxes is not because it IS an airbox, but because it is way too small for its intended (or OUR performance intended) purpose. Seems like the ideal is a presurized box that is huge - like a huge empty beach ball you could attach to the rear fender. No thanks.