Topic: Classic Bonneville Racer

[BomberMann650]

Can't wait for August!

[Old Scrambler]

Now I know where the HP went.....BENT VALVES

Following the dyno-run with Scott I pulled the head and slowly began examining EVERYTHING Yes, the motor was down on compression partially due to a total of 8-thou lost to slightly thicker base and head-gaskets. BUT, the real loss was very slightly bent valves and one very egged-out valve guide. That puff of smoke at the end of the last dyno-run was likely caused by cylinder pressure escaping resulting in a very high level of oil-pressure. Its the only time that notable oil was found in the catch-can

All of the intake valves will need to be replaced along with guides & seals. The beehive springs are well within spec. The valve seats will also need some work. How soon this will take place is not known because I may have to send the head to Wisconsin. No locals are equipped to work with 5.5mm valve-stems and guides.........unless Salt Lake City is affordable.

We just bought a newer RV and have travel plans for the summer and fall. More later...........

[bear]

Well it's always good to nail down a problem but once again we find the god's of speed are cruel god's.

[Jerry Rxman Griffin aka MuthaF'er]

Well #$%*!!

What's your diagnosis of the cause? Running too many rpm with the beehives? Too tight clearance? Missed shifts on the throttle? All of the above? But with a thicker base gasket? Only 1 guide?! Was that the one that lost the adjuster nut?

Lot of time before Bonneville. Getrdun.

[Old Scrambler]

All of the above were contributors..........but the loose adjuster and lost lash-cap on #1 caused the most damage. #1 is about 7-thou out of shape at the outer edge...........the others are between 2 and 3-thou which IF they were from a Chevy would be within factory spec

#1 seat is well dished but will likely clean-up.

New Farrea valves and related items are still available for the 2.2L Prelude motor that I adapted to this build.

[Jerry Rxman Griffin aka MuthaF'er]

Pistons still good?

[Old Scrambler]

No evidence of piston to valve contact. Pistons and rings will get closer inspection, but at first look with a 'spy-glass' in my hand they appear to be good. The high-lift cam puts extra side-force on the valves which causes the guides to wear so the valves don't seat exactly as when new. Although the lash-caps are a snug-fit, each valve stem has a witness mark at the edge of the cap with #1 showing a shallow grove. The exhaust valves are good but have slight witness-marks at the caps. All 8 valve components will be exchanged for new units. Because the original stems were shortened, the tips were not hardened. I will try to solve that by having Ferrea do the machining and use their lash-cap & collar interlocking design. Their Super-Alloy valves are $42.55 each and for a little more I could get hollow-stem & or Ti units for an additional 40-percent weight reduction

Part of the decision on which units to get will be influenced by another AHRMA racer and rather famous motorcycle restoration guru (Retro-Speed) who wishes to build a new race-motor using a 410 head. Anyone else???   

[PeWe]

Dennis, you do not have an extra head to use while repairing the faulty one?

A spare head good to have.

I had a head swapping day today. As I thought, IN seats not cut deep enough for 10 mm lift. Valve keepers groove in valve stems start 9.5mm over the valve stem seal. Should be at least 10.5mm.
Will check EX too, valve lift 9.4 so 10mm a must.

I should have checked that last year, twice after first huge oil drinking episode when I blamed head torque only.

Another head went on today, not much used MLS looked as new and reused. This head have seats cut deep enough.
Good to work from home

I understand the feeling when something recently modified goes bad.
Good reason to repair and do better than before!!

I have lost the count of head, cylinder lifting and  swapping plus various cams in my blue K6 the last 2 years. More before that.

It just run better and better.

I got a late lunch with a good french red wine (Chateauneuf-du-Pape) after head was torqued.
Now on my 2nd Gin Tonic. Fresh oil smell still around me despite a hot shower.

Will assemble, time cam and all the rest tomorrow. Synch carbs on Sunday.

Call a bike shop and beg for dyno time on Monday.

I hope you'll find inspiration to fix your engine, look forward and forget the repairs. I'm sure it will run better next time.
There are trophies waiting for you!

//Per

[Jerry Rxman Griffin aka MuthaF'er]

"for a little more"  and........ key word is little. 150 mph?!

[Old Scrambler]

Thanks for the encouragement..............its my flat wallet that's holding me back. I do have a spare 410 head.......actually 3 of them   But they are not ported at time.

For reference: the little more is going from $19 for stainless to $42.55 for super-alloy to $180 per valve for Ti

As long as I run gasoline the stainless are good, but actual fuel should have higher-heat components........especially on the exhaust side

[scottly]

Go with the stainless. BTW, not sure what you mean by "fuel", but I thought alcohol fuels ran cooler, due to some sort of "latent heat" scientifical stuff?

[Old Scrambler]

Anything other than gasoline is FUEL. Yes, alcohol burns cooler, but you need a lot of it.  A few cars are set up for E85. Maybe I need to build another motor?

I may have found a shop in Idaho Falls that will do the work.

Scott.......regarding your dyno..........you should consider parking it on the pavement at the truck-stop or the 'boat-ramp', or at the old army airport hanger..........talk to Delvine or the Mayor.  I plan to be a volunteer or spectator this year.

[Jerry Rxman Griffin aka MuthaF'er]

"I plan to be a volunteer or spectator this year"

hello?

[MRieck]

Now I know where the HP went.....BENT VALVES

Following the dyno-run with Scott I pulled the head and slowly began examining EVERYTHING Yes, the motor was down on compression partially due to a total of 8-thou lost to slightly thicker base and head-gaskets. BUT, the real loss was very slightly bent valves and one very egged-out valve guide. That puff of smoke at the end of the last dyno-run was likely caused by cylinder pressure escaping resulting in a very high level of oil-pressure. Its the only time that notable oil was found in the catch-can

All of the intake valves will need to be replaced along with guides & seals. The beehive springs are well within spec. The valve seats will also need some work. How soon this will take place is not known because I may have to send the head to Wisconsin. No locals are equipped to work with 5.5mm valve-stems and guides.........unless Salt Lake City is affordable.

We just bought a newer RV and have travel plans for the summer and fall. More later...........

   What kind of valve guide material?

[Old Scrambler]

Copper/Bronz from Ferrea............I said badly egged-out relative to a race-spec engine...........I've seen much worse in a street-bike tear-down.

Jerry......our plan was to be in Alaska for the entire summer.......now it looks like more local RV trips but no SPEED-RUNS this year.

[Jerry Rxman Griffin aka MuthaF'er]

Yes, plans change as do valves. Good to know.

Did you get the new RV?

[Old Scrambler]

The 2017 Class C is getting stocked as I make myself familiar with its modern features and air-bags on the rear suspension. Selling the old unit is a bit of a pain...........3 ebay buyers backed out.........the last one told me to keep the deposit for my trouble

[RAFster122s]

So, PM me about your old one and what it’s issues are and what you are asking or sellers have won the bid with. Too many scammers on FB marketplace these days and all the craiglister tire kickers and low ballers have found it as well…

[Sam Green Racing]

Hi Dennis, sorry if this is a bit off track but last night in the pub, someone asked me if it was true that people pee on a tree before getting on the salt.
I told them it was but couldn't for the life of me remember what sort of tree it was and do people still do it ?
Sam. 

[PeWe]

I could not resist to Google it.
Lemon tree.
That's why lemons are yellow?

[Sam Green Racing]

I could not resist to Google it.
Lemon tree.
That's why lemons are yellow?

Like, don't eat yellow snow. lol. I thought it might be but couldn't find anything on Google, what did you put in Google ?

[PeWe]

I could not resist to Google it.
Lemon tree.
That's why lemons are yellow?

Like, don't eat yellow snow. lol. I thought it might be but couldn't find anything on Google, what did you put in Google ?

Bonneville salt flats + pee tree

[Old Scrambler]

Just returned from a few weeks in the bush........There are no trees at the salt flats

Burt Monroe asked has neighbor kid (Tommy?) to pee on the small lemon tree in Burt's backyard while he was on his trips to Bonneville.

[BomberMann650]

Scott.......regarding your dyno..........you should consider parking it on the pavement at the truck-stop or the 'boat-ramp', or at the old army airport hanger..........talk to Delvine or the Mayor.  I plan to be a volunteer or spectator this year.

Scotts bringing a dyno to wendover?

[Old Scrambler]

That's the plan...........but confirm directly with Scott