i think there is a lot of people not understanding how these new systems are going to work with EGR. The over heating problem is going to get bigger a lot bigger. You can burn these gases under the hood a t temp's up to 700 c and not have over heating problems. Like i have pointed out manufactures don't want to admit they can't come up with a solution to this problem. They are going to have to redesign trucks from 6,000kg and over fro the European and North American markets. Will they want to spend this money probably not so they will just use the old design and pretend there is no problem.

I followed a couple of threads about some Nissans & Toyotas that apparently have inherant design flaws that make them prone to overheating. After all the ususal suspects were ruled out the last resort was to install hood vents. My concern was that there was some sort of safety issue that required an air tight engine compartment ( in case of fire- the operator would be safer from burns, etc).

The problem with an air tight engine compartment is that if the engine isn't running, the engine compartment is not getting any air flow what so ever ( the engine gets it's hottest a few minutes after shut down due to no coolant flow) & if the unit does this cycle multiple times per shift, the engine can get so hot the cooling system can't keep up, there's not much reserve anymore with cooling systems.

On 2 trucks I have installed vents on the radiator cover between the counterweight & hood assy for just this reason. I just wanted to make sure I wasn't violating any safety protocols- Thanks for all your inputs

a safety issue?
no i doubt it
if a truck is getting hot enough to become a safety problem in such a way as to worry about it catching on fire? There are alot of things to consider before you blame the design of the truck.
I believe swoop hit on alot of it
Environment will be one of the first things evaluated if such a situation came into play...
The condition of the lifttruck and how it has been maintained.

Any design problems (if any) would probably be the lower down on the list of things to consider in a situation like that.

these kind of airtight engine compartments have been in the market for a long time, i believe some of the first ones i saw were with the yales 10 or 15yrs ago, give or take a couple years, and i'm sure there are other mfg's that designed similar ones back then. Sound abatement and sealing has been common since then.

In any case where i ran across an overheating issue due to poor air flow it was always a last effort solution but we would wind up installing extra vents in the hood either in the front or on the sides, depending on how the design of the hood would allow us to install them. I have only had to do this in a couple of occasions over the years of my working on lifttrucks though. And the foremost reason for the modification was because the truck was running in an extreme envrionmental situation like high dust or dirt or cotton etc.

Yes i can agree with part of what you are saying. I think Crown were the first to put the fan that can blow the truck radiator of and now some others have followed this. But i wonder just how much the new reg have had a effect on this. I know that manufactures don't want to talk about this because it is a major problem that they are struggling to solve and really want to keep this quite. But until this is really opened up and talked about with people on forums speaking about the problems they incur like bb forks has done ,these problems won't be raised. The answer some times to just say yes this is a major problem and many different people could say why don't you try this. Operators should not be relied on to have to do checks because they just don't sometime have time to do it , Yes they can sit there push a button on the truck to clear the radiator but the rubbish would just blow back later. What is needed is a better solution that can be done wants a week. Sometimes the dust that gets into the radiator needs to be cleaned out with a power washer it just wont be blown out by the fan. I think this is the major problem the fan just cant blow out all the dust and after time this causes blockages or if it is blown out just stay's in the engine compartment

i believe they do this for all of the above...
1) more direct airflow
2) ergonomics and noise control for the operator

yes it turns the truck into a floor sweeper and the radiator does catch alot of debris... but in that arguement i do believe these engineers are counting on the companies to keep thier floors clean and the operators part in doing thier daily checks and blowing off of the lifts before and/or after each shift.

Since the trucks designs have moved towards these directions the customer has to become more involved in daily mainteneance, unlike the old days when they could just wait for the tech to come out and service the truck like before.

the only problem with this is you have to rely on EVERY part of the equasion to work and unfortunatly we all know the customer/operator does not do thier daily checks as they should. So..... is the problem REALLY a design issue? or a consumer issue? THAT is moreso the question i think.

In almost every environment where the customer does his part and the tech does his part i havent seen any overheating issues.

Just my.02 worth

I guess the days are gone of the Clark C25B with the big beautiful chrome plated air intake scoops in the side doors.

There is issues with fire on certain trucks i have been told with EGR systems. These get that hot there can be a fire in certain applications. Some have to be fitted with special heat guards but this still is a problem. The temp's that these can get up to is very high. I would not recommend you put vents in hood for a number of reasons. One being you could be liable if any thing was to happen and the manufacture would say that these vents were not supposed to be on the truck. My suggestion would be go back to manufacture and tell them that the trucks are not suitable as they stand and need modification's

My concern was that it was a safety issue ( fire ) or some other regulation that was being followed. I have been reluctanct to install cooling vents in the hood for this reason. I have a few trucks I service that would benefit from being cooled down.

From what i have seen the new engines need a lot more air to cool them because of the EGR system. The problem might not have been as bad before but with these new systems there needs to be more air flow. It will be interesting on how the new trucks go with this system i think this is going to become a major problem for manufactures and service companies alike.

All the heat is trapped in the engine compartment and can't get out making the engine over heat , Again because all dust is sucked up from under the truck as the driver moves along this again causes the radiator to get blocked and again goes to the problem of over heating. manufactures are unwilling to spend money on re developing their range because of small market only Europe and North America need them so this problem is only going to get larger

it 'should' give the air flow a more directed route, and actually that should cool better, giving less "disturbed" airflow [where the cool air flow doesn't go past the engine and through the radiator, but gets blown around inside the engine compartment], causing further restrictions to the 'proper' air flow.

It's all about the drive to improve "ergonomics" & "safety". The less vibration and noise that impacts the operator and the people around them the better.
I'm not saying I agree - seems that forklifts now make a pretty good sweeper as well! Only problem is that instead of *** the stuff up into a bag or tank, they just throw it on the radiator!

No just good old bad design. It will get worse when new system come in. Is this on the new tier 4 i trucks