Well, I have never posted a "build" thread in the past - it will serve as my re-build as my car has been running for some time. Something that might be interesting for the H20 folks is a performance based cooling system - oil included.

The silver lining associated with the engine down is I have been intending to make the cooling updates for well over a year now. Its such a PITA I have delayed engagement.

LS engines are notorious for running high oil temps on track - GM will tell you it is ok - I believe it is not. Likewise, mid-engine cars have a notoriously difficult time controlling temperatures simply because of the location of the engine and cooling systems. This is exacerbated with additional power.

I walked the pits of the Walter Mitty Classic at Road Atlanta last year and took a bunch of pictures. All late-model mid-engined prototypes used Water-to-oil heat exchangers in lieu of oil-to-air. It adds a serious layer of complexity since the coolant now has to carry the burden of dispersing allot of extra energy. That is what I will be updating: all lines, the radiator, shroud addition, coolant distribution chambers, etc. One of the benefits of this new system is the ugly-as-sin rooftop oil cooler scoop will be eliminated (not to mention the drag that thing is causing ~ slowing me down)!

Just remember, along with most other members here, I ain't no "Tygaboy"!

Tony

Sounds like a fun project. I'll be following along.

Pulled the engine today and dismantled to inspect for damage. Turns out I did in fact have a rod bearing failure - or so it appears. The cylinders all look and feel outstanding, as do the lifter bores - thank God. The heads were undamaged, pushrods were all straight, all very good signs and news.

One odd discovery that is pictured below was the fractured lower dry sump pump mount...chicken or egg scenario. Did this cause the failure or do the failure cause the mount to fracture. Dunno?

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How Ti rods should look...
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This will be fun to watch and make snide comments on

I'm watching you,Tony...

I love the VW emblem over your door!

This will be very slow moving...especially the cooling mods. The engine should be on its way to Houston by early next week. The shop is not mine (jfyi) - just a good friend who kindly allows me to invade his retirement space and time when a lift is needed.

FWIW: I decided to run DOT approved braided hydraulic lines that were built to my specifications. Since this is a "build thread" I will retroactively share what I compiled. Due to the speeds and performance I expected from this car - I wanted to KNOW everything was as good as it could be. I had a heavy equipment manufacturer (CAT's and such) execute it - each run is coated in a different color sheath (front, rear, clutch). I do not have a single "adapter" in my system - all are direct connections. The clutch line terminates at the MC on one side into the slave cylinder on the other.

Tony

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Being blinded by the glare off of the shop floor, I'm not able to see any other details...this must be from some parallel universe from my shop...

Tony, Can you tell me a little about the Trans? Cayman/Boxster? and what year? are you running cooling on it as well? And I assume it is holding up?

thanks

It is a 6-speed Boxster- G8620 out of a 2001...we intended to install cooling and have all the equipment/fittings but never felt it was ultimately necessary. We run a max of 25 minute sessions and surely it gets hot but has held up well with over 50-hours to date. My original strategy is they would become throw-away every other year - cooled the jets on retrofitting the case for cooling. It shifts as well now as it did on day number one.

Tony

Very cool Tony! Eliminating all adapters is awesome and really quite impressive!

The last racecar had custom lines made by BMRS with correct end fittings as well as integral hard line sections and it was a dream to assemble.

Well, here is another project I am working on...I'll make this "thread" ALL of my build threads...wrapped up in one. So my late friend chose to cut the rear fenders trackside due to clearance issues - very crudly! I understand you gotta do what is necessary but it was ugly!

The "moon/speed" wheels are really cool - I've never seen another Cobra with them but they extend 4" inches outside the fenders. I had to chose to revert to stock wheels and tires or modify (as in correct) the body. I chose to make the hotrod more of a hotrod.

I liked the contour of the front fenders and thought the continuity of having flares added to the rear would be an appropriate design/improvement. We splashed the front flares, created molds, and then fitted them to the rear fenders. Here is where we are today...

Tony

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Now here is the big question..input is welcome. One of the visual highlights of a Shelby 427 are tapering/cutting down and in rear fenders. By transferring the front flare to the rear we grafted in the shape as well and it now has a squred off base.

Big question: Do I cut the flare back to be more representative of an original tapered style or maintain the cars Rebel status all the way to the end - and stay square? Pictures that clearly explain what I am referring too...

Traditional rear
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or Squared off flare
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I assume it looks different in person but I like the squared design. It's not trying to be original and, based on the angle used in the pic, I like the way it mirrors the shape of the exhaust.
I vote keep it square.

I like the tapered. The rear of my fenders do it and I love it. The square just screams to me fiberglass racecar.

https://www.youtube.com/watch?v=F9K0B8axdvU

The roll cage adds to the squared design as well.

AZBanks - LOL - Gotcha ya!

Chris - Yeah, I saw the same blend with the exhaust - heck, everyone can see it.

Andyrew - It IS a fiberglass racer and it screams everything!

Costa - The cage really "uglies up" the car too! The problem: It is a 12-point certified cage that is really well executed - from a safety standpoint.

Modification Idear: I have been thinking of converting the cage to a "track-day" eligible/worthy system. This was intended to give the driver a chance at 220+ mph. It would still have full Nascar door bars on both sides that would be fully concealed - red lines would be eliminated. Aesthetically, I believe this would make a world of difference. Thoughts?

Tony

Is someone really good with Photoshop? Can we get a visual without the marked cage?
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Decisions made...cutting the cage and training the flares. No brainer in person...thanks for the thoughts.

Tony

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The trim line looks to me to be more aggressive than the "traditional" one above....

Meaning too much in the middle area & not enough French curve at the bottom.....I like curvy bottoms...

I like your posts and builds. I figure if you aren't a Tygaboy you must be his cousin.

I am trying to understand the physics here. The heat goes from the oil to the water to the air. How is this more efficient than oil to air direct? Sooner or later you are cooling stuff with ambient air moving across as big a surface as you can afford to have. The possibilities that I can think of are A) it easier to produce a larger water radiator than an oil radiator, or B) the heat transfer from oil to water and/or water to air adds up to better than oil to air - though I cannot figure why that would be true. If you could use the phase change from liquid water to steam, it would produce tremendous heat absorption. But only as long as you have water left, so I don't think that is it. Water has a higher heat capacity, so you can get more heat transfer with less flow with water.

How does this work? I have to believe that these cars are built by people who know their physics a lot better than I do.

FWIW, I like the reverse curve on the rear of the Cobra at top. I can't see how you are going to come away with anything but a great looking car in the end though.

It's not more efficient since you have an intermediate transport process increasing entropy. There can be a few benefits:
-You don't need to run oil lines all over the place so packaging is easier. I'm assuming they use engine cooling water for oil cooling (so no separate system) too like most bikes.
-Plumbing weight is greatly reduced since you now can get rid of oil lines and a small increase in water line OD results in little overall weight increase. Oil-to-water heat exchangers are also likely pretty light since you don't need much heat transfer area due to higher overall heat transfer coefficients.
-You can also better optimize your oil pump sizing since you don't need to worry about a viscosity change of 2+ orders of magnitude which greatly increases cold line pressure drop-a big deal with really long, essentially laminar flow, lines.
-Possibly better temperature control, especially if you're using a booster pump on the water side to control flow through the heat exchanger.

Worn - The water to oil heat exchangers are more efficient...a unit measuring roughly a foot long (like my cooler) has the equivalent capacity of a 40-row oil to air cooler. The other benefit is what was pointed out in the last post - it is far easier to plumb oil to a cooler located in the rear of the chassis than to the front. All of this improved energy loss doesn't come free...my entire cooling system from lines, junction boxes, radiator and an improved shroud is all being replaced.

Another big difference between the two systems is the oil being cooled will be off of the scavenge circuit - not the pressure side. It will move slowly enough to give the cooler/coolant a better chance to pull the heat from the oil. I will probably then pass either the coolant or the oil through an liquid to air cooler with a fan pack after the first cooler. The coolant will rejoin the engines heading towards the radiator - the oil will then go the dry sump tank waiting to be sucked into the engine.

I do not pretend for a moment to know the scientific explanations or basis but having gone through what doesn't work - I have learned quite a bit. Thanks for the thoughts...

Tony

Another interesting thing is that a water/oil heat exchanger can actually help get the oil up to operating temperature faster! A pretty neat side benefit, IMHO.

--DD

I hear you John...I worked on adding more radius to the lower third of the flare. Either way, we'll make progress - working on this again Tuesday evening - maybe. Thanks for the input.

Tony

Sorry, but this is very incorrect. Slower speeds do not allow more heat transfer. You're actually decreasing the internal convention coefficients of your cooler (reducing it's overall "efficiency"), so you need more temperature difference to transfer the same amount of energy. The perceived "slower=colder" is because now you have less fluid mass to cool, so the energy balance works out that the outgoing fluid is cooler (assume the two flows are going in opposite directions).



If you are going to add a second air-to-fluid cooler, I would do it on the oil side. Putting it on the water side will be a less efficient use of components since now you'll be lowering the water temperature into your radiator, lower temperature difference between the radiator inlet and air inlet, effectively reducing heat transfer rates. It's just not the most efficient use of energy. On the oil side you can use it for fine temperature control, depending on what oil and and water temperatures you like. I wouldn't be surprised if some GT cars are built like this because water temperatures in their pressurized coolant systems are probably much higher than desired oil temperatures.

Just something to think about.

With a bit more curve that is going to look fantastic!

Interesting. Aviad and ARE who both contributed to the construction of my dry sump system gave that "rationale" as to why they wanted me to cool the scavenge circuit. My existing cooling system is inadequate (IMO) to add the W2O cooler as it sits currently...time will tell which method is more effective.

Tony

[quote name='Cracker' date='Oct 28 2017, 07:52 AM' post='2542805']
Interesting. Aviad and ARE who both contributed to the construction of my dry sump system gave that "rationale" as to why they wanted me to cool the scavenge circuit. My existing cooling system is inadequate (IMO) to add the W2O cooler as it sits currently...time will tell which method is more effective.

Tony

[quote name='jd74914' post='2542797' date='Oct 28 2017, 11:12 AM']
You see the slower so it has time to cool story bandied about in the hot rod magazines too. It is not correct physically, but it sounds right. A lot of people who know a huge amount about engines aren't like me trying to figure things out going from college class to reality. As everyone knows, reality can turn around and bite you.

Given the somewhat tragic nature of your dilemma it is nice to see you looking at it from a bluer skies ahead perspective. Courage there.

With all due respect...nothing tragic occurred. The car will be improved as a result of this event - all is good.

For those who enjoy the Cobra project...I just spent a good amount of time working on trying to get the flares sorted. I had a "duh" moment after a few free-hand attempts! it occurred to me that I simply needed to make a template of the front fenders matching radius and apply it to the rear flares. Bingo! I also lowered the ride height a smidge and with every refinement, the car just keeps getting better and better - at least in person it does!

PS: I hope this enough of a "curvy bottom" for you John!

Tony

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Won't matter as the volume will be the same. "Slower" would be a higher capacity heat exchanger, as it stays in the cooler longer.


The amount of heat being removed will still be the same, doesn't matter if it is transferred by water or oil. Since you hinted it was running hotter than you would like I'd focus on the radiator and leave the second cooler out until you find the radiator insufficient.

The volume is not necessarily the same - the two circuits operate on completely different pumps and pick-up sources. I just do not understand where you are drawing that parallel from...we are installing what should prove to be a far more efficient radiator.

T

Flairs look Great Tony!!!

I'm surprised they didn't recommend the pressure side going something like tank>pressure pump>filter>oil cooler. This would give you the least aerated oil which would both help overall parasitic pumping loses since you wouldn't be forcing oil+air bubbles through a cooler and likely improve heat transfer. I'd be a bit worried about air collecting at a high point and effectively blocking some of the channels.

They definitely have more practical experience there, it's just interesting. Not what I would have expected for sure. I've only designed one dry sump system (it did work really well) and was not super impressed with the level of design data available from the pump manufacturer or heat exchanger manufacturers. Neither Aviad or Armstrong have much actual data on their sites. It looks like a lot of kits which culminated from BTDT. I'm not trying to say they are not very good at what they do, but its just very different than what you see when buying aerospace or industrial parts.

Slightly tangent, but the automotive aftermarket is a funny place. To date the only radiator/intercooler supplier I've talked to who can offer real engineering data is Bell-they actually deal with mass flows and energy dissipation requirements, not "HP". But maybe that's because of Gerhard Schruf?


Sorry, confused there. Maybe I'm misunderstanding everything? I assume you have a number of pickup scavenge pumps>single outlet>tank and then a tank> pressure pump>engine. Then the coolant side uses a single pump/radiator with branch line through oil cooler?


The slower thing just kills me-it's everywhere.

For sure, reality is tough. When you look at coupled systems, not a lot of stuff is very straightforward and sometimes it 'appears' to go against conventional physics. I think that's where some of these wives tales come into play. Then when you model the whole thing, the math shows deviation from physical expectations are caused by a bunch of factors acting against each other, etc.

Sorry to if I'm coming off as an armchair-internet-know-it-all. Just trying to share some of my engineering perspective and seeing what other people are doing is interesting. I've spent close to 10 years now designing/troubleshooting thermal management systems for power plants and high end aerospace/marine test systems and am almost finished with my PhD which focuses on aerospace combustion/heat transfer/fluids systems so I like to think I have some relevant experience.

That new curve is perfect!!

Thanks guys! When you finally get it right - it is obvious!

Jim - Your insight is much appreciated and welcomed...I certainly fall under the often described (by crews doing the real work) as the "the dummy behind the wheel"!

Tony

Because it's a fixed amount of oil in a closed circuit and I'm assuming you will be cooling 100% of the pumped oil.
I think you're over thinking it.

Fast in a little tube cools better than slow in a big tube when capacity is equal.

...you are just not tracking with how my system is plumbed and functions (it appears)

Tony

[quote name='Chris914n6' date='Oct 28 2017, 05:09 PM'
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I think you're over thinking it.
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Yep, I think that works fine!

Cut and happy...now more glass work to give the flares edge some body and strength. The exposed tire is what I was ultimately after - thanks for the suggestions!

Tony

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That's a very pretty curve. Nice paint, too!

Look like I'm too late to comment on the rest flares. I was goi g to recommend you leave them and paint the area that was not part of the taper black. That way the visual would be that the flare had a taper but the glass would still be there.

Maybe next time I'll be I time.

Thanks Billy...I don't dwell too long on decisions. See'em and move on...hope you are well!

Tony

Had some life events that has caused some delays...

1) The LS7 is in Houston in the process of being rebuilt...this isn't a quick fix.
2) The Fireant BOSS body work is being approved for the nest step tomorrow...paint within a couple weeks.
3) Much needed items were modified at the machine shop for the Boss motor - should have been this way from the get-go.
4) I started mocking up the Gulf40 drivetrain - ultimately, the trans would be pulled apart, blasted and powder-coated. More to come shortly on this...the picture at the bottom is a chassis like mine - this represents the potential of what is possible.

Tony

500hp/450 tq 363 ci (full forged)
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G86-20 6-speed / Borla Induction 50 mm TB's
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Wow... That car is amazing...

Will the GT be tracked or raced at all, street and show, or what exactly? It's going to be something fantastic for sure - great build Tony, keep us up on things.
And Happy Thanksgiving!

Andyrew and Mike,

That car IS amazing...certainly the pinnacle of what can be done with a good amount of custom parts. That car is a dual purpose car - I believe mine will only be a street car. I know first hand the monumental difference between a hot-rod and a reliable, effective race car - they are universes apart!

I also own a true dedicated sequential shift race car - it would run circles around the Gulf40; therefore, I am 99% sure it will be a street-car-hot-rod-vehicle.

The Coyote motor would be really sweet but they also complicate the build in this small chassis - obviously, it can be done but at the cost of cost. I now have all of the major mechanical components for the entire build...these require an estimated 1000-1250 man-hours. It is hard to believe but they are very complex builds - especially if you are targeting the example above - that has WAY more time invested + talent!

PS: Happy Thanksgiving to you as well!

Tony

Anybody like 180-degree exhaust?

Tony

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Here is the original 289 out of #1067...our system has an identical layout - just a little more compact; fairly close though!
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