Trojan Boat Forum

do any of you know why some manifolds have these tubes in them and some dont? whats the tube do?
this one has no tube in it

this one has a tube in it

whats the difference?

I take it this is a Chrysler 318. Read this, it'll tell you all about it. Not too many people are aware of it's importance. If your application dictates that it should be there, then it's highly recommended that it be installed.

http://www.marineengine.com/parts/osco_ ... /index.htm

Hope that helps

That clears that up, but I do not know where you get one. My V drives do not set at a severe angle but the manifold I sent you came from my old or original install and as a V drive is the lesser of angle. Example the intake manifold for the V drive is 3 degree at the Carby and normal is 11 degree at the carby.

correction I have tubes ordered, see my last entry below.

Larry, have you tried Beacon, Osco, Marinepartssource.com, chryslermarineparts.com, bpi.ebasicpower.com? All of these list that part.

Hope that helps

big D, they are are I have not checked yet if you can order one. I can see what they can do, interesting my V drives are at a very slight angle to horzontal and the docs indicate the tube is for extreme angle. That said my original stuff had them.

I still do not know if they are needed or not?

Anyone with experienc jump in on this one. I may have to make an alteration with the tube, IMO not but could be wrong.

In any case:

Out of stock:
Usually ships
in 5-7 days

I would think that a RWC v-drive would not need these tubes because the water exit is at the high point of the manifold.

I've always preffered to ensure these are installed, engine angled or not. Makes for better cooling distribution/circulation, directing water flow. Missing tubes could be for an app where it was determined not needed or FWC manifold system.

In my v drives the high point is at the exit and air cannot get trapped there, If the tubes were used on it air could get trapped as it would reverse the exit end to the low point and ergo leaving possible trapping.

That said the manifold that Andy has is an original installed on my old vdrive engine.

I am going to contact the expert at Marysville and see what I can find out.

Experts please oping.

larryeddington wrote:In my v drives the high point is at the exit....

Larry, I'm just trying to picture why that would be, been a while since I've been on one, and I don't think I currently have access to a v-drive/Chrysler setup. Even in a v-drive set up, the engine may be tilted a bit. Are you saying the output is at the opposite end of the manifold? Just trying to picture this again. Do you have pics of your plumbing/cooling circuit?

Thanks Big D

When Andy asked me about the tube it was a new one on me.

V drives have the engines facing Aft and the risers are on the aft end. Cooling water enters manifolds at the forward or boward end of the manifold. The engine transimission assembly is tilted towards the bow end, ergo any trapped air would go out the higher riser end.

That said apparently my old manifold has tubes, that is what andy asked about, as he now has one of my used manifolds. I am going to examine the one I have left to see what gives.

They are available from Barr and Osco. I talked to marysville and they said they would use them. A picture of the tube indicates it is not only a pipe but sort of a spray bar configuration that would provide more even cooling. I have also seen reference to use where needed.

Most likely I will get some or make some, prices are around $35 each.

Okay guys I have about exhausted my research capabilities. Here are pics of the tube, I got the one out of my old cracked manifold and cleaned it up and it is in good shape, I have orderred me 3 more, now the pictures and what I have and have not found out:



Above is my V drive engine as you can see the risers off the high end of the assembly which should allivate any air trapment issues for me, conventioal installation has some.











Above are pics of the tube by itself, It has six holes in it like a spray bar and you can see one end has a flange and the other has about a 1 inch cut in it, further the end with the cut has a restrictor to limit amount of flow.

OSCO fact sheet tell us to insert the tube from the lowest end of manifold that would normally put the flanged end nder the riser, and indeed that was where mine was but on the high end, in normal drives that would put the cut end at the high point of the exhaust manifold. But with V drives the high part is at the riser which as I have said would allow the air to pass out of manifold through the cuts in the tube if they were at that end. If Flange is under the riser any trapped air is sealed from escape IMO it should go to the lower end. If I put the flange under my riser it should not purge air correctly, in other words just the reverse of what should happen but that is the way it came.

OSCO also tells us to put water into exhaust manifold at lowest point not through the end cap or water will go straight through and overboard. All of the 318s I have seen inject the raw cooling water to manifold though an end cap barb.

I am going to call OSCO, and Marysville on Monday and pick their brains.

Anyone with opinions or hard data jump in.

I now how mine came but it does not seem to be correct.

I just got off the phone with Bob at Beacon regarding the tubes. According to bob they do not put them back in most of the time with no problems. You should be able to put your hand on the exhaust manifold when running. Bob thinks it does not really make any difference which end of the manifold you put the flanged in.

I am going to use them and will insert them, per Osco from the lower end of the manifold. 1. it is easer to take off the cap than removing and installing the risers and two I know there will be no air pocket installing it that way.

Still on Monday I am contacting Osco and Marysville.

i know i have seen more manifolds without tubes than with tubes. im so confused

Larry, let us know what you find out from them.

I have yet to see a Trojan v-drive application. Is that the way all of them are set up in terms of exhaust? The reason I asked earlier Larry about the configuration, was I'm used to seeing the elbows at the v-drive end. So forward of the engine thus at low end of the manifold. Both elbows into an exhaust tube, bend around and along side out the aft.

antlr-king wrote:i know i have seen more manifolds without tubes than with tubes. im so confused

The important thing to note, and Larry touched on this earlier, is that in the end, the manifold should not be so hot that you can't touch it. If you're getting water out the exhaust, the temp gages read ok, and there are no real hot spots on top of the maniflods, you should be ok. I should also mention that Chryslers are notorious for air locks that take a while to disipate without these tubes. Usually a problem at the beginning of the sean, or after not being run for a while, or after servicing harware where water in the cooling system is drained back.