Block Heaters

[Jim Roe]

I have a set of Detroit 671T's with 2800 hours and just had the injectors replaced with rebuilds. Probably made a mistake because now the engines are hard to start and I get excessive smoke at start up. Smoke does reduce dramatically after a couple of minutes. I had the mechanic do a compression check on two cylinders of each engine and the results were good. He did replace two of the replacement injectors on each engine that apparently were leaking. That did not eliminate the smoke however and the port engine is still hard to start after sitting for several days in temperatures of 50 to 70 degrees.

He feels strongly that block heaters would fix the problem. He quoted a price of around $300 for each heater and about a days labor to install. The boat is kept in SW Florida. The mechanic I used is a registered Detroit mechanic.

Any thoughts if this would be money well spent?

Jim Roe

 

[MikeP]

The block heaters being on/off do not make our 8V71TI's start any differently they just DRAMATICALLY reduce the smoke on start up.

They will start with/without heaters within 2-3 seconds of hitting the start button. If it's cool, say under 50F and no heaters, they may hunt for maybe 5-10 seconds before settling. But there is no difference in the speed of "ignition." The Mosquitos love the block heaters...

I think they are a good thing and well worth having but if they make the difference in actual starting in the sense that the engines will start in say 5 seconds as opposed to 10, I'd suggest there is some other issue that should be looked at.

 

[Pete]

One suggestion. If you want block heaters, the type that are installed in the water jackets of the engines, stop by your local heavy truck repair facility and buy them in the $50 - $60 range. I have this type and they work great.

Pete

 

[Genesis]

If you have hard starting after an injector change and did not before, something's wrong and block heaters are not the answer.

Leaking injectors will cause smoke (and potential washdown) problems and a bad pattern causes poor combustion, smoke and potential washdown problems.

Improper timing or a poorly-set rack can cause hard starting, especially when cold. My money is on something being out of spec or otherwise sloppily-done.

 

[StratPlan61]

FWIW, I installed Wolverine block heaters (500w pad) on each on my 12V71TIs. I think I paid $140 or so per pad and it took me a couple hours per engine. I sanded down, the inboard deep side of each oil pan, to bare metal for proper adhesion. Not a bad job, just in a hard-to-reach place to work.

 

[stormchaser]

I'd have to agree with Gen...if all was fine until the injectors were changed out, and all of a sudden you've got smoke and a hard start...something is wrong with the injectors...get you mechanic to fix his mistake, at his own cost.

 

[saltshaker]

I agree with the others with regard to your starting issues. Block heaters won't fix it. As Mike stated, your engines should start just fine even when temps are in the 50's. My old 8V71's would start a bit slower and hunt a bit when the temps stayed below 40. Smoke is reduced with the heaters and the do spin up a bit faster. There are a lot of benefits to having the heaters, but they won't fix starting issues.

As for the cost, that seems very high. I have coolant heaters with adjustable thermostats. MY engines are easy to get to so it only took about 1.5-2 hrs for both engines. Add a couple of hours to add 2 dedicated AC circuits to the ER. Pad style engine heaters require more prep but still shouldn't take anywhere near a full day to install. If you have reasonable access, do the job yourself. Its very simple

There was someone here on the forum that had a similar problem after replacing injectors. I believe a few of the rebuilt injectors were bad Do a search and see what you can find.

 

[Jim Roe]

Thanks to all for your reply. I found the thread on this issue and it was really helpful to get a good understanding on various systems out there.

Jack, could you share with me the manufacturer you used for your system? Also, do you leave your heaters on 24/7 since you have thermostats?

Jim

 

[saltshaker]

Jim,
Can't remember what brand but will check the next time I'm at the boat. I do leave them on 24/7. Keeps the condensation down and no smoke on start up. Also keeps the ER nice and warm when the outside temps get low.

 

[REBrueckner]

My experience with 8v71TI's over 11 years is quite different...my engines start within a second when warm. At 40 to 50 degrees I doubt they would have ever started.. Block heaters enable me to start the engines with a one or two second crank with a chilly engine room...Did it last week when the engine room temp was 47 degrees.

Reliabilt injectors have reportedly been quite UNreliable for a number of years...reported here and elsewhere.....after a suggested source was posted here on Sams, I let my mechanic know and he has used them (don't remember the name) since without a problem and at lower cost....

When I had a "tune up" after about eight years, same injectors, both my engines were slightly MORE difficult to start when cold....The same mechanic who has done all my work for 25 years double checked... tolerances were ok...they are still just a tad harder to start than before the "improvement"....

 

[Avenger]

Reliabilt injectors have reportedly been quite UNreliable for a number of years...reported here and elsewhere.....after a suggested source was posted here on Sams, I let my mechanic know and he has used them (don't remember the name) since without a problem and at lower cost....

INTERSTATE-McBEE

www.interstate-mcbee.com

 

[Jim Roe]

Thanks Jack, I appreciate you checking for me. Thanks Rob for the injector info. You are right I installed the same injectors and had to replace 2 on each engine. They are UNreliable.

After reviewing all the great information from previous threads, I think I will go with Kim Hotstarts. That is the heater that my DD mechanic recommends. I was able to save a considerable amount by buying direct from a distributor rather than from DD. DD quoted me $350 per engine and I can get it for $217 an engine. It is a direct immersion heater that mounts in the square plate on the block (model # DD151-WOC). There is a thermocord that attaches to the heater (model #A-2822-OB). The thermocord consists of a 4' 3 prong plug, a splitter with a 3' cord that connects to the exterior end of the heater element (square plate on block) and a 3' cord with the thermostat at it's end.

I am traveling and will not be able to look at my block for a couple weeks. The question I have is...does anyone know if there is a NPT opening available on the block where the thermostat screws into? I am assuming there is since this part is specified for my engines...671T's. Has anyone installed the above on there 671T's? Can you give me any feedback? I am hoping to save some bucks and do the installation myself.

If anyone wants information regarding the above you can go to Kim Hotstarts web page and click on "RESOURCES" and then click "Catalog". The heater element is on page 50 and the thermocord is on page 56.

 

[stormchaser]

Have you discussed with your mechanic the thoughts about the hard starting and smoking being related to his work? I still think band-aiding the problem with block heaters is a mistake. Not to say I don't like block heaters...I definitely do. I kept mine set at 50*F all winter and didn't have to winterize anything in the engine rooms. When I want to go for a ride, 1-2 hours at full on and she starts with virtually no smoke and no hunting.

 

[saltshaker]

Jim,
Mine are Kim Hotstarts 1500 Watt.

 

[Jim Roe]

Jack

Thanks for the information. Did you do the installation yourself? How were the instructions?

Jim

 

[saltshaker]

I installed mine myself. Very simple and straight forward. My thermostats are different from yours. I have a dial type thermostat with a capillary tube. The block heater is wired to the thermostat and the thermostat was a plug on it. I decided to use a plug instead of hardwiring so I could unplug them and have 2 dedicated 110V circuits in the ER. My setup might be a little different than yours since I have 6V92TA's.

 

[Nick]

I have the heaters and thermocords you described on671tis. The thermal probe which houses the thermostat is installed in the fresh water manifold in at the forward part of the engine. I'll take a photo next week for you. send me your email address.

 

[Jim Roe]

Thanks Jack and Nick. I really appreciate your help.

Nick, my email is "bigjimroe@aol.com". Thanks again for your consideration.

Jim

 

[stormchaser]

I'd recommend editing that and removing your email address or spell it out like sucnandsuch at suchandsuch.com There are webcrawlers that do nothing but search sites for any listed email address and adds them to spam mailing lists...

Dave
IT Systems Administrator for a local credit union

 

[MicroKap]

One thing my mechanic told me is to make sure that my Kim Hotstarts block heaters are turned off prior to starting the engines. Something about the coolant moving rapidly over the "plug" that may cause "boiling" on the surface of the heater element. Don't know if this is accurate, but I'm sure somebody else on the forum can enlighten us whether this is accurate or not.