Intercooler for turbo arrow 3

N6399c

Looking to discuss intercooler on arrow 3 turbo. Need to get these hot temps down on my plane. AZ based and fly a lot of Colorado and Utah too.
Any information would be appreciated greatly.
KPJS.llc
N6399C
1978 turbo arrow 3

Scott Sherer

I'm interested in this discussion, too. I have Merlin UDC and Electroair electronic ignition and I'm interested in the Whelen/Lopresti cowl with cowl flaps, intercooler and Gami's. Let's start a discussion!

lkstarcher

I have a '77 Turbo Arrow with the Merlyn, an intercooler, GAMI injectors and the SureFly electronic ignition. The claims from TurboPlus is a ~140F drop in induction air temps. I have owned the plane since 2009 and flown extensively in both Texas and Flroida in the summer and almost every summer in Montana, Colorado and New Mexico and my hottest CHT in cruise climb (~ 500 - 600 ft/ min) do not exceed 380F and TIT of less than 1525F (Also my personal temperarure limits for the plane), typically hottest CHT is under 350F in climb full rich at 75% power (adjusted to the Inercooler company's power setting based on outside temperatures). I consider both the Merlyn and an intercooler must haves for a Turbo Arrow, the GAMI and electronic ignition should be high on one list of investments. Both the Merlyn and the intercooler help in reducing the CHT / TIT temps. Another benefit is the critical altitude with both is in the high teens, I can maintain 75% power to 17,500 ft which is the highest I have flow the plane. AVWEB and Aviation Consumer have both written about the benefits of the Merlyn and intercooler for the Turbo Arrow. https://www.avweb.com/ownership/intercoolers-turbo-enhancement/

Scott Sherer

Thanks, good article. I learned from it and I'm now looking at intercoolers...

N6399c

I spoke to owner at Lopresti about the arrow cowl and installation. It’s 11-12 grand and there aren’t any temperature drop information that I was able to get in writing.
For 6-7 grand at turbo plus and another 40-50 hours for installation cost, the turbo does have numbers that I can see.
Would love to have both the cowl and turbo but that’s too much money for this plane owner. Have to choose, I’d go intercooler over a cowling with just directional airflow and not cooling the turbo or cylinders.
Just my opinion.
Love the LoPresti look and product, but not the bang for the buck.
KPJS.llc
N6398c

N6399c

Both turbo plus and LoPresti were wonderful folks to talk to. Very helpful as well.

N6399c

PS, I do have the Merlyn but not GAMI or electronic ignition.

lkstarcher

Make sure your baffling is in good shape and that it properly seals the top of the engine with the cowling to get best CHT cooling.

Tarrow

I have the LoPresti cowling, Merlyn and GAMI's. Money well spent. (Our stock cowling was falling apart).

Stan Owen

I have the Turbo Plus intercooler with cowl flaps, Merlyn, pressurized mags, and GAMI's. I consider all essential for my flying. Plane easily goes to 20,000 for the Rocky Mountains with CHT's never above 380 in the climb. Temperature drop across the intercooler is typically between 30 to 40 degrees C depending on the airspeed and OAT. Cowl flaps are really only necessary for slow flight on hot days. Necessary for me as I am in Civil Air Search and Rescue (same as CAP) and will be low and slow in search mode.

Scott Sherer

Hi Stan,
How did you have cowl flaps installed? What product did you use?

jjouscg01@yahoo.com

My Turbo Arrow IV with the Lopresti Cowl, MT Composite prop, Airflow System Intercooler (No longer in production) Merlyn UDC, and electroair electronic ignition. I will be taking my first long cross country with it this week to Wisconsin (I live in Corpus Christi) since the cowling, composite prop and electronic ignition was installed. We’ll see if all these mods made on the plane live up to their promise.

empannin

John, looks fantastic! have a great flight and let us know how it goes.

jjouscg01@yahoo.com

WILCO

Scott Sherer

I can't wait to see it You should be at Racine airport shortly. Hangar should be waiting...

jjouscg01@yahoo.com

Yes sir. Should be Wednesday around 5PM

jjouscg01@yahoo.com

The flight to Oshkosh from Rockport, Texas and back went well. I did not see any cylinder head temps. Higher than 370 in cruise. TIT was around 1570. I typically run at 70% power and 12.5 GPH. As stated earlier in this string, I have the LoPresti Cowl, Merlyn UDC, Intercooler, GAMIjectors, electroair electronic ignition and a MT Composite prop. I used 7,000 and 8,000 ft for my cross country altitudes. In short, i have done everything possible to keep the CHT’s down and it seems to be working. My results may not be typical though.

hueyseg

I have the Merlyn UDC, GAMI's, pressurized mags but no intercooler. I do not have temp issues at all. In climb with MP of 35" on a hot day, CHT's are under 350. I fly 65% power usually at 10K and CHT's are 310 with fuel flow of 11 gal per hour. At higher altitudes I find the need for higher power setting of 75% but temps are the same with fuel flow of 12.
I have considered the intercooler but I don't know if there would be any need. I always wondered why my Turbo Arrow III runs cooler than many I talk to.
My question is if an intercooler can provide any other benefits beyond cooler temps?

Stan Owen

In the early years of the Turbo Plus intercooler upgrades, the cowl flaps were part of the package. They dropped them as they were found not necessary to keep the engine cool, plus, to reduce kit and installation costs. Unless you are into a low and slow and hot flight, I would say they are not needed.

empannin

hsegura,
An intercooler lowers the temps into the cylinders and can reduce the risk of detonation. This could be an important advantage if there was a failure/clog in an injector that leaned the cylinder out at high power settings.