Team Go Dog, Go! Modified Partial Streamliners

[wobblywalrus]

Second of three photos.

[wobblywalrus]

Third of three photos.

[fordboy628]

Looking good Bo.

You made a wise choice going with Kibblewhite.

[wobblywalrus]

Mark, it works out pretty good.  They make the guides, intake valve seats, valves, titanium keepers, and sell the custom springs.  Also, they sell the cam follower buckets with the shims between the valve tips and the bottoms of the buckets.  I sent them the cylinder head, cams, a manifold, carb, exhaust pipe stub, and an air filter.  Also, lots of money.  The head comes back ready to be bolted on with flow test results.

The head manifold, and carbs are at Kibblewhite.  Fortunately there are enough parts in the junk pile to bolt up a simulation of the race motor.  The carbs are parallel to each other and close together.  There is this big square frame tube near them and it prevents the installation of large filters.  Some adapters are needed so the filters can be located where there is room for them.  Also, there needs to be enough space left over for the battery, starter solenoid, fuse box, blinker relay, and some other relay that I do not know what it is for.

A few hours were spent with the K and N on-line catalog.  A pair of RV1090 cylindrical filters, 3.5 inches wide and 6 inches long, with 2.25 inch spigots cocked at a 10 degree angle will fit in the gaps between the things that I cannot move.  I ordered a pair with the socks that go over them to keep the salt away from the elements.  The plan is to position them on the bike in the only places they logically fit and then to figure out how to connect them to the carbs and where to put all of the other carp that belongs on that part of the bike.

The "Horsepower Chain" book gives some good info on single runner intake systems.  A plenum helps to dampen out the intake pulses.  This lessens the intensity of the big gulp through the filter when the intake valve opens.  This reduces deltaP factor and promotes volumetric efficiency.  The plan is to build plenums into the connections between the filters and the carbs and to connect the plenums to each other.  This project will keep the ol' walrus busy and out of trouble for a week or two.

[wobblywalrus]

The job now is to make some adapters with plenums to connect the carbs to the air filters.  These need to look nice so they will be professionally welded.  The metal is .125 inches thick throughout.  Experience tells me the welding is easier and looks better if the sheets are the same thickness.  6061 alloy is used for all pieces.  It is easier to weld like alloys together and this alloy is one of the more corrosion resistant.

The online cut-to-order metal vendors make this quick, easy, and reasonably priced.  Long gone are the days when a guy has to buy 10 or 20 foot lengths to get a small piece, or has to scrounge through the loose ends at some fabrication shop and get metals of unknown alloy.   

[wobblywalrus]

The head is ported, the valve springs have been verified to provide enough tension, and the valve train has enough travel to handle the cams without binding.  The intake valve velocity onto the seats is 4 feet per second with the recommended .008 bucket top to cam clearance.  Reducing the clearance to .005 lowers the valve seat velocity to just over 3 feet per second.  Kibblewhite prefers no more than 2.9 feet per second.  This is a problem I might need to live with.

The intake cam lobes are tall enough to run off the sides of the buckets.  Wider buckets might be the answer.  Maybe some more parabola in the cam lobes?  Possibly the cam lobes are taller than they need to be based on what the head can flow.  All are things I am looking at for a solution.   

[wobblywalrus]

The previous is the intake.  This is the exhaust.

[wobblywalrus]

The head flow data is in Reply 2396.  The flow does not increase appreciably at lifts over .400  The lift is .445.  Some milder cams might be the answer.

[RidgeRunner]

Bo

     Some interesting comments by Jon Kasse on cylinder head design and air flow based on his experiences in the article "Hemi vs Wedge Shootout", latest [Aug '16] issue of Car Craft magazine.  They might be well worth your read and consideration as you work out the compromises needed for your build.

               Ed

[Sporty Dan]

Bo, if you go with a lower lift will you be able to keep the current ramps on the cam lobes? I guess I mean, will you be able to find a lobe shape with a lower lift that won't compromise the current airflow numbers?

[wobblywalrus]

Ed, I am looking for that magazine.

Dan, the expert at Kibblewhite said the cam is giving me a lot of duration at maximum flow.  He says they do not make square lobes so the cam needs to lift the valves further than needed to give the desired duration.  I cannot fine other cams so these will do.  We are looking at installing bigger cam follower buckets.

[ggl205]

While you are still searching for cam answers, it may be worth calling Dema Elgin at Super Lobes. He has been at this cam game for decades and has a wealth of information and experience with all types of engines. But he will ask you for a great deal of data from your flow numbers and measurements for the engine itself. He will cam your engine to obtain all it can deliver if that is what you are after. Dema is a Bonneville guy too and imparts his knowledge freely. His shop is in Redwood City, California, I think.

John

[wobblywalrus]

John, thanks for telling me about Dema.  He will get a call if these cams do not do the job.

This morning I did the obvious.  A call went out to the ladies at WebCam who ground them.  They had the order sheet with my name on it and all sorts of notes about followers.  Bigger 30mm followers out of a Yamaha FZR1800 boat motor will do the trick.  Supertech Performance sells the things.  The tops are a little bit thicker than the followers I am using now.  Some length needs to be ground off the intake valve stems, or maybe new shorter intake valves are needed.  Kibblewhite is figuring this out.

Tall cams, big carbs, and mongo air filters are the big project.  I am going to retire from LSR in 2018 so I only have a few years left to kill myself.  I had better get to work and make this motor a runner.   

[ggl205]

I am going to retire from LSR in 2018 so I only have a few years left to kill myself.  I had better get to work and make this motor a runner.   

HAH! I understand completely.

[wobblywalrus]

This year these are optimized, air filtration, valve sizes, porting, combustion chamber shape, compression ratio, and header and exhaust.  The bigger cam followers, tall cams, and big carbs will be done next year.  This will be another "R and D" year.  Hopefully the record will not be bumped any higher.  I ran out of time and money.  It is time to get the last ceramics done, put the engine together, break it in, dyno it, and go to the races.