Looking for Crankshaft Specialst

[Tonerjockey]

Good points.

re saving dough. I was kvetching to a racing buddy about spending $50 to 1st flight out some parts. Turns out they won't be used by the grinder until a week later. His reply was "spend it now to get it done... or you'll spend it later to get it done."

heh heh

Ducati pumps eh? New grist for the think mill.

BTW:
Light fuse. Retire quickly.
Happy Independance Day

Alex

 

[5154Guzzi]

The Daytona pump is larger than the V11 series and probably overkill for your 750 motor, especially if you dont match port the case. The late model jackal sump is an improvement, or at the very least, there is a adapter availble that will let you use the later model oil filter, which itself will handle the higher volume. The V11 series pump is larger than the 1000cc and smaller series from the 80`s. It`s good to at least chamfer the holes in the case to match the oil pump, kinda like what you had done on your rod journals . I`d go with the V11 oil pump Alex, it would be more within your budget , be dependable and get the job done. Consider rod bearings as being an expendable consummable. They are only good for so much abuse in a high winding hi output motor. The trick is inspecting and replacing them on a regular basis before something bad happens.

Marine Crankshaft in the Irvine/ Costa Mesa area is a quality machine shop also.

Good luck ! Bill

 

[Tonerjockey]

Oil pressure increased.

A thinner washer on the relief plug increased the relief valve trigger pressure from about 60# to about 80#.

Need to monitor when assembled.

Alex

 

[Chris R]

Increasing oil pump volume is not always a good idea as it increases parasitic losses. I'd only do it if you have a good reason to. We sometimes gear down Ducati pumps to spin slower.

Good point Ed.

This is not a case where more is necessarily merrier - you want enough pressure to reliably supply the bearings and no more.

Although at 8K I doubt that cavitation is the cause I think that it is something to consider. The way to do reduce the possibility of cavitation (in addition to opening up the feeds to the pump as large as is physically possible) is to pick a higher volume pump and run it slower which will entail a different drive gear. I assume that Dr. John must have found that things were beginning to get marginal on his endurance racer at higher speeds which is why they upped the pump size soon after his employment at Guzzi.

The relief valve is there to protect the oil filter from damage during cold starts - like winter cold - so I expect setting it to a higher value for racing as the oil will never be that cold. The rule of thumb is 10 psi per 1K RPM hot.

Again the later much larger oil filter is the way to go.

You might consider also adding an accusump to protect the engine against momentary pressure loss as well as making a windage tray with appropriate baffles to protect the pump screen from being uncovered. I like the look of the windage tray that MG cycle did on their racebike - I would copy and then thoroughly test it. I have done some windage tray design and it is way trickier than it looks - a crank scraper or two is essential IME.

Chris R

 

[Tonerjockey]

Had the crank cut to 1st under. Replaced main and rod big end bearings. Adjusted relief valve to about 80 PSI.
Ran about 25 miles locally, changed oil, ran another 25, changed oil and then ran 5 passes at Bonneville (3 mile courses).
Removed engine and dissasembled.
Bearings look good... not destroyed, but worn.
Ordered new rod bearings from Stein Dinse and will run World Finals with them.
I'm looking for a larger volume pump now but not ready to pop for a new one at this time.
Considering installing oil filter system.
Looking at windage plates but not convinced that one would be bennificial in LSR.

Too much fun!!!!!

BTW changing to a 7-33 rear

Alex

 

[Chris R]

I think that a decent windage tray would be actually pretty beneficial - I did some development work at Judd and had a good look at the development of their windage trays. They had a pretty sophisticated test rig that could more or less simulate the g's encountered on the track and provide instantaneous measurements of the amount of oil trapped on the crank. They also had a very cool strobe setup so you could see what was happening.

Without a windage tray (with scrapers and oil guides) the crank looks like a big dough hook. Like mixing dough, a fair bit of energy is used mixing the oil as well as beating air into the oil. Yes on a 80-90 horse motor we are probably talking 2-3hp but it is free horsepower - provided the windage tray actually works. It is more complex than it looks making a proper tray and intuition does not always work.

The same applies to pulling vacuum in the crankcase (which also increases the rings' efficiency) which is why Cosworth et al fit such huge scavenge pumps these days.

I would also think that at the speeds you are running ram air is actually worth doing- again it takes some experimentation with Pitots to get the float bowls vented at the ram pressure.

Im Boco Lupo!

 

[Tonerjockey]

I am still not completely sold on windage trays for this Guzzi in LSR. The washing-machine effect, I gotta believe, would be more pronounced in road racing or even hill climbing. In LSR this bike develops G forces only in the lower gears. Once in 3rd it's just a long straight pull. Any MixMastering of oil, and its associated impact on power, would be minimal I think.

Having said that, I would be interested in seeing ANY improvement. Who has sussed out the windage tray for V7 Sport? Who makes the best available? If it's realistically priced ( <4 Carrillo CARR bolts) I'll bite and see.

As far as modification to the intake (Ram Air etc) this is strictly Verboten in Production Class. The bike must look TOTALLY STOCK. OEM carbs for make/model/year and stock airbox. My friends joke about NOS in the frame though.... :?

Production frame - Production Pushrod engine (P-PP) class is sometimes reffered to as the liers and cheaters club. Not be me of course.


Alex

 

[Chris R]

Given there are limited things you can do in your class reducing windage would be something I would explore. It takes more power than you think to move that oil.

You can quantify the effect of a good windage tray pretty easily on the dyno. The same goes with a crankcase evacuation system - just hook up a vacuum pump with a gauge to the crankcase and take notes.

There is some confusion about what a windage tray is: don't confuse baffles in an oil pan with a proper tray. The baffles are there to make sure that the oil pickup is always submerged- not such a big deal in your application as the oil is mainly headed in one direction towards the back of the sump. The windage tray Pete Roper does is more an oil pan control baffle - which is certainly valuable and necessary.

A windage tray should have a blade (or two) that shears the oil off the crank and directs it into the sump. Some screens to de-aereate the oil are also required. Tinwork that tries to keep the oil tight to the crank is critical to the design.

THere are no commercially available windage trays available that I know of. If you look at MG cycle's racebike someone has done what looks like to me an intelligent design. That being said windage tray design is somewhat tricky and not always intuitive - a bit like airflow. Depending where you are in your development, most of your effort should be on the flow bench and exhaust tuning (unless that is also illegal in which case I would move to a different class!).

 

[Hudriwudri]

Hi there

i can only repeat what chris said and put even more emphasis on his comment/point of flowbench and exhaust development as the heads dont look at all too convincing to me (dont have the bench here as of yet unfortunately but am allready preparing ;-) ) and judging by the primary lenghts also the exhaust could like some further looking into tube diameters and lengths.

kind regards

Christian

 

[Tonerjockey]

re exh and intake tuning:

Here's a nifty cakle8r. A nice place to start.

I dunno where I got this from... maybe this forum. Anyway, here yar:

http://www.mez.co.uk/mezporting/exhaust_length.html

Alex

 

[Hudriwudri]

hi alex

hmm dunno how reliable that calculator is?? have some doubts bout it.
anyways to cut it short if you want to let me know your cam specs at 0.0040, valve diameters ex/int, piston diameter, stroke, compression ratio, port diameters, also up to which number youre willing to rev the "red pig" so i know where to set the target rpm, i will try to figure out some numbers for you.
Just gimme some time as i currently have to travel a lot for work and when im home im trying to work on the moving (countrywise!!) of my workshop.

kind regards

christian

 

[Tonerjockey]

Hey Christian,

So far I have 1.5" pipes run 2X the calculated legnth. Since the bike has to look stock I couldn't make 2 into 1 headers. I also couldn't run the pipes short as my calculations say I should so I emptied out the mufflers (need to look stock) and doubled the pipe legnth. I ran the extra pipe legnth into the empty muffs.

The heads were done by Phil Wyatt. Intake port about 36mm. Big intake valve ressed for clearance. I can't shorten the intake legnth (from valve to carb bell tip).

Need to use VHB30 Dellortos. Bored those to 32mm with an additional 1mm oval (in the vertical direction). I found that 32mm carbs provide about 7% increase in top end. These bored HVB's should provide additional help (I hope). Bored intake manifolds of course. That was an interesting exersize.

The cam is a Megacycle 620-7. The pistons are custom jobs with 1mm clearance all around. .1" to exh and .08" to intake valves.

Static compression is about 18:1 but dynamic is MUCH less (around 9:1 or so) due to that whacky cam.

At Word Finals next month, I am taking an addition carb set up to experiment with. We'll see haw 36's work out.

Also need to set up air filters when using PHF's. Salt on piston. The VHB's use the stock airbox.

Alex