Milwaukee Midget

[Interested Observer]

“The highest load the rod bolt "sees" is at "unloaded TDC rock-over" . . .”

That is the highest load that the bolted joint must sustain, repeatedly.  Hopefully, the highest load the rod bolt “sees” is mostly its preload, which would be well in excess of the “rock-over” load, plus a minor alternating load due to the elasticity of the system.  (And, discounting any bending stresses due to the prying action of the rod cap.)

[fordboy628]

Fordboy & MM;

"So we are all on the same page here.    The highest load the rod bolt "sees" is at "unloaded TDC rock-over", ie, TDC during overlap of the open valves.    Only the bolts (or the bolts and nuts, depending on your con-rod set), hold things together during the load reversal.    There must be sufficient tensile strength and "preload" for the fastener to withstand these loads, repeatedly."

That's a key point regarding fatigue life that is often overlooked or misunderstood. You NEVER want the tension in the (rod) bolt to drop to zero during the cycle. If it does, that bolt will fail VERY soon.

Regards, Neil  Tucson, AZ

“The highest load the rod bolt "sees" is at "unloaded TDC rock-over" . . .”

That is the highest load that the bolted joint must sustain, repeatedly.  Hopefully, the highest load the rod bolt “sees” is mostly its preload, which would be well in excess of the “rock-over” load, plus a minor alternating load due to the elasticity of the system.  (And, discounting any bending stresses due to the prying action of the rod cap.)

Actually guys, I misspoke.    The highest load the rod bolt should see is: "the preload", which better be in excess of the total of any of the other loads.

Whenever the preload in any tensioned fastener drops to zero, very bad things happen, very quickly.     My WAG on the number of cycles to failure in that situation, would be some where between 1 and 100, best case . . . .  Not nearly long enough to it shut off, before the really expensive noises start . . . . . . . .

There is always "some" bending stress on the bolts as the unloaded (or less loaded) assembly changes direction.    It is the main reason why I don't like puny bolts or small parting line sections on con-rod big ends, they tend to go "bang" and the engineers/builders then say "OOPS"!     As in the case of the original Ilmore IndyCar engines.     They went with a 3/8ths dia rod bolt and light big end.     A 7/16ths bolt and a beefier big end solved the problem, which were probably bending stresses at the parting line.

Neil & IO,
Thanks for adding some clarification to the thought.
 
Fordboy

[Milwaukee Midget]

I reworked my adapter plate idea from a few weeks back.  My initial try proved the theory, this one actually clears the head.  A shorter belt is on order –



My chief concern is that the ½” adapter is actually only bolted to the block through two bolts through the water pump. 
 

What I’m hoping to do is stabilize adapter and the pump motor with a long bolt through the alternator ear on the pump, and with spacers, tie it into the back alternator bracket, the holes of which are currently being used to hold the engine to the stand.  I’ll also stabilize the rest of the pump motor with an exhaust clamp and a turnbuckle around the same bolt.  The threaded piece is in place for the mock-up – I think the actual stock alternator bolt will do the trick – provided I can find it.   

Yeah, it’s all a bit Mickey Mouse, but there just isn’t anything else on the front to hang the motor from.

Other new parts arrived – like, the day I pulled the rods and pistons – so the scraper and windage tray will be fitted after everything else gets done.

[wisdonm]

Why did you go through all that effort and still have questionable reliability when a remotely located inline pump would do the job, without the Mickey Mouse factor?

[Milwaukee Midget]

Why did you go through all that effort and still have questionable reliability when a remotely located inline pump would do the job, without the Mickey Mouse factor?

"You can always count on Americans to do the right thing - after they've tried everything else."

 Winston Churchill

Fair question, Don - and rest assured, I still haven't ruled it out.  I recall you suggesting a sweet setup that sacrifices a water pump housing.  If that's the direction I need to go, I'll do it. 

For now, my reasoning is this -

The plumbing is already in place, and based on the existing pump.  I'm hoping to avoid a complete replumb.

This setup I can mock up as a unit, and it will work on both the dyno and in the car.  I've already put together the portable plumbing kit for the dyno, and we know it doesn't leak too much.  Additionally, we can determine just how much hp the engine drive is consuming.  We can test both the electric and the crank drive without having to swap out a modified pump housing. 

An outboard pump on the dyno - sure, it can be done - ground it to the dyno, run power to it, attach it to . . . something . . ., but using the Moroso gets us up and testing faster.  Tearing out the shaft and impeller and threading the snout for an AN fitting?  Any less of a bother than what I've done?  I'd call it a horse apiece.

This is almost done, and it includes the possibility of using the old system as a backup.

Rationale, or rationalization, either way, I've got to keep moving forward.

I'm 100 days out.




 

[fordboy628]

For those looking to ceramic coat/anti-friction coat their pistons, Baurle Auto Sport Services has quoted MM $25/$30 per piston for both coatings.    Quote is based on the small diameter (2.815") of the pistons.    Ceramic is top only, anti-friction is skirt only, and they are baked on coatings.

Call Ken @ 630-465-8155  for a quote if interested.

 
Fordboy

[Ron Gibson]

Fordboy-Orwhateverundercoverofdarknessaliasyoumaytochosetouse
I value your past experiences and expertise greatly. What is your opinion on either or both coatings MM is thinking about as far as increased HP and or longevity with no other changes? And would that scale up or change with larger engines?

TIA  Ron

[fordboy628]

Fordboy-Orwhateverundercoverofdarknessaliasyoumaytochosetouse
I value your past experiences and expertise greatly. What is your opinion on either or both coatings MM is thinking about as far as increased HP and or longevity with no other changes? And would that scale up or change with larger engines?

TIA  Ron

On the V-8 stuff I was "experimenting" with, on a N/A 358 cubic inch Chevy based 750 bhp research "mule" the thermal barrier coatings gained about 6/8 bhp in the usable range.     This scales down to 1.0/1.3 bhp for MM's 61 cu. in. "Grenade".

The anti-friction coatings used on the engines above gained about 10/15 bhp in the usable range and that scales down to 1.5/2.6 bhp.

The current best output for the "Grenade" was 95.1 bhp.    We've gained a bit of cylinder head airflow, raised the C/R a touch, added the crank-scraper/windage tray, and are adding the piston coatings.     We also have some tuning parts we are going to try out.    This is all with the idea of pushing the peak torque up a touch in the rpm range and gaining a bit of top end bhp as a result of "jacking/rocking the torque curve".

The LSR brain-trust is currently thinking is that MM needs to increase bhp @ 550 feet above sea level to 100/105 to have adequate bhp at 4400 feet to have a chance to approach the record.    I'm thinking that 100 bhp is achievable with the current piston limitations, and anything above that would be icing on the cake.     Chris is taking a "I'm leaving nothing on the plate" attitude.

Coatings, properly applied, have a good track record of adding some bhp.     We are talking about the 1 or 2% range here for most of these things, so this is not insignificant.     Combining the numbers this becomes ~3%, which is a pretty good per dollar gain.     Typical V-8 piston coatings ran about $400 then, for a gain of 22/23 bhp.

My experience is that the anti-friction coatings usually don't "save" parts if your clearances are correct to begin with.    They "help" if things are too tight to start off.     Thermal barrier coatings on the other hand, do prevent piston damage if your "tune-up" gets "a bit out of line", but the line is pretty narrow.     If you are "dancing on the edge" and the temp drops 10/20 degrees, thermal barriers can save your posterior.     Once things start to go though, it's all over pretty quickly.   

 
Fordboy

[Milwaukee Midget]

Chris is taking a "I'm leaving nothing on the plate" attitude.

Additionally, I have the front end slammed to the point that the car might be mistaken for a hovercraft, I've removed the front brakes, backed off the shoes on the rear brakes, and will spend some time making sure the body panels are properly aligned.  I ran 1/8 " of toe on the alignment last year - I intend to run that straight up this year.

I'm just hoping to stack as many miniscule advantages into one, great big small advantage.

[WOODY@DDLLC]

Chris, the wonderfully frustrating world of optimization welcomes you - where tenacity aka anality always pays off! 

Some articles on connecting rod selection and critical engine fasteners: http://www.aera.org/ep/EPQ2-2014/index.html

[krusty]

     Chris, just make sure you know the "turns" so you can go to a bit of toe-in without stringing or using a bar. I am running 1/32" in on each side (set individually). Granted 850+ hp makes it easier to push through the added resistance    If it doesn't feel great on the first pass, crank it in a bit.

     vic

[fordboy628]

I reworked my adapter plate idea from a few weeks back.  My initial try proved the theory, this one actually clears the head.  A shorter belt is on order –



My chief concern is that the ½” adapter is actually only bolted to the block through two bolts through the water pump. 
 

What I’m hoping to do is stabilize adapter and the pump motor with a long bolt through the alternator ear on the pump, and with spacers, tie it into the back alternator bracket, the holes of which are currently being used to hold the engine to the stand.  I’ll also stabilize the rest of the pump motor with an exhaust clamp and a turnbuckle around the same bolt.  The threaded piece is in place for the mock-up – I think the actual stock alternator bolt will do the trick – provided I can find it.   

Yeah, it’s all a bit Mickey Mouse, but there just isn’t anything else on the front to hang the motor from.

Other new parts arrived – like, the day I pulled the rods and pistons – so the scraper and windage tray will be fitted after everything else gets done.

midget,

All the electric water pump setup has to do for now is get the "Grenade" through the dyno session.    If the mounting has to be "beefed up", that can be attended to prior to Saltfest.   

The windage tray/scraper assembly looks very good.    Hope it adds a Shetland pony or three to the output . . . . . . .   

Back to my Lotus & MGB projects.    Going to post up some airflow numbers on the race MGB head currently under test, it is interesting . . . ,  although I'm now interested in a cool and refreshing beverage, or three . . . . 
 
Fordboy

[Milwaukee Midget]

All the electric water pump setup has to do for now is get the "Grenade" through the dyno session.    If the mounting has to be "beefed up", that can be attended to prior to Saltfest.   

Actually, now that I have all of the proper length bolts in place and everything is torqued down, it's remarkably stable. 

Henceforth, upgraded to "Mortimer Mouse".

[gkabbt]

Chris,
Saw this Saab Sonnett here in Wilmington today:







I wondered if it is the same one you were telling me about that could possibly move up to I/GT.

Gregg

[Rob]

I'm assuming that line is for tech not to actually run, what's on it's roof?

Cheers,
Rob