Auto Diesel (Yeah, again, but...)

[tom kane]

The simple explanation provided should be sufficient for those who choose to research further.Some may not understand it.The positive and negative waves operate in the induction and exhaust,and are used to ram or expel.

[woodboat]

I can't find any data that would support an exhaust pulse being able to carry water from a riser all the way back to the cylinder and ultimately in the cumbustion chamber. In fact some 2 stoke designs rely on this exhaust wave to help pull a fresh mixture in from the intake.

[Frosty]

Tom. I did not mean to single you out and beat up on you. However the posative and negative effects of the air flow of a petrol driven internal combustion engine are well understood. The trick is to get these negative and posative waves in the right position at the right time to fascilitate and improve the gass flow through the engine. The effect of gasses being pushed from one cylinder to help scavange another at a particular RPM is what is trying to be achieved. I believe 5 cylinder engines are better at this. I was paticularly concerned at your use of the words ''sea water which now appears to have been replaced with 'moist air'. You suggested that this moist air could go so far back into the engine as to affect spark plugs, cylinger, and rings . If your suggesting that this could happen if some one designed a real bodge up manifold then I suppose it could be, but todays modern manifolds are specificaly designed not to do this.

[tom kane]

Hi woodboat,you may find it difficult to find that information,which may detract from good sales of a particular product.I thought that wet exhaust problems were fairly well known.Some posters are aware that steam is in a wet exhaust manifold,it takes little work to work out that it is easily carried back and forth by near sonic pulse waves,or just evaporation.Two stroke wet exhausts have similar problems,the back pressure in the exhaust helps to keep incoming mixture where it is needed.

[tom kane]

jackfrost,would you call the propulsion in this image an investment,would you like to buy it after this owner had discarded it.It makes simple propulsion like shaft and adjustable surface drives look attractive.

[tom kane]

Originally Posted by gonzo

I never denied any engine can be made to work in a boat. My argument is about economics. At least in the US, used marine engines are plentiful and fairly inexpensive. An old boat with a rebuildable engine can be had for less than U$1000. That includes transmission or outdrive and everything else you can salvage. I don't see how you can get an automotive engine, even for free, and make it work cheaper.

I have never said that auto engines are better than marine engines but that there are advantages in using auto engines.A discarded marine engine could be very expensive parts and labour wise compared to an auto engine from a smashed or rusted body.Marine propulsion and engines have been in close contact with a salt laden moisture and water.There are many marine motors and outboards in many countries around the world that are not economic to repair because of the labour and parts costs involved,I have several. I am sure many people would not want to buy a secondhand marine engine,but would not have second thoughts buying a secondhand auto.

[Frosty]

Thank you for the photo but I cant really see it very well. What is it? I dont really undstand what it is you saying. I have never ever considerd a boat as an investment, I was saying that an auto motor in a boat would 'not' enhance your investment ('IF' you were the type of person who considerd a boat an investment.) I most certainly do not.
I dont understand the surface drive bit, I hadnt mentioned surface drives, --well not in this thread.
I have found this web site that will explain to you about the exhaust reversion, as you suggested that sea water, is natural and normal in marine exhaust manifolds. This one of many web sites actually describes how this reversion can under some circumstances bring water back and warns of severe engine failure if it were to be allowed. It is absalutely not acceptable for water in that manifold.
www.hardin-marine.com/Instructions/Cyclone_Header_Instalation.pdf

[Filmdaddy]

Gonzo. I'm back, and I have learned a WHOLE lot. I understand now why you are so adamant about slamming anyone who wants to try something different. You're a vested interest! You're in the business of selling marine engines. And so you shoot down any idea that doesn't create potential customers for you. You're like the fox trying to convince the farmer not to get a dog.
Guess what. I don't care about your opinion or whether you are insulted or offended or indignant. You have no credibility with me.

[gonzo]

All my posts have verifiable data. There are many emotional issues from people that want to be different or think they are smarter. It is easy to claim that it is all a conspiracy theory, but facts don't change. I can't see what vested interest I can have in somebody else rebuilding an engine, marine or otherwise. If I wanted to make money, I would sell a load of part to some inexperienced experimenter. My posts show it is cheaper to find a used marine engine and rebuild or repair it. There are thousands that only see fresh water use. Film daddy you have learned little if all you see is my occupation and not my knowledge.

[woodboat]

Tom, OK, let's use an example. take a V8 american inboard. You have a long log for the exhaust. Then you have the riser. At the end of the riser you dump the raw water for discharge. All four cylinders are pushing out. You closest cylider to the raw water discharge is about 12 inches. Are you saying that water can travel back through the exhaust against the flow and enter the combustion chamber. Realizing that there are pulses I still can't see this happening and in fact have never sen evidence of this on any engine around here in my entire life. Now I have had some logs and risers go bad sometimes the results completely destroyed an otherwise brand new motor. So a poorly engineered log could cause this but have never seen it with a commercially produced product. So if you were to take a stock car engine and add readily available used marine parts there would not be an issue.

[tom kane]

Thanks jackfrost, for confirming the risks of running wet exhaust,which is what I suggested.We seem to have missed each others points otherwise.

[tom kane]

Originally Posted by woodboat

Tom, OK, let's use an example. take a V8 american inboard. You have a long log for the exhaust. Then you have the riser. At the end of the riser you dump the raw water for discharge. All four cylinders are pushing out. You closest cylider to the raw water discharge is about 12 inches. Are you saying that water can travel back through the exhaust against the flow and enter the combustion chamber. Realizing that there are pulses I still can't see this happening and in fact have never sen evidence of this on any engine around here in my entire life. Now I have had some logs and risers go bad sometimes the results completely destroyed an otherwise brand new motor. So a poorly engineered log could cause this but have never seen it with a commercially produced product. So if you were to take a stock car engine and add readily available used marine parts there would not be an issue.

Yes woodboat....... With a wet exhaust the risks of moisture,being carried back to the valve seats and beyound are always there.Take a look at jackfrost`s last reply.

[Filmdaddy]

Tom Kane - Took a little doing, but I found the site, the instructions, and the manufacturer says you are absolutely right. Kind of makes you wonder about the "experts" here, doesn't it?

[gonzo]

Post the site and instructions.

[Filmdaddy]

The direct link gives you a 404. Here's the step-by. Go to www.hardin-marine.com, then click on Tech Support. That opens a pull down which reads Installation Instructions. Click and open Cyclone Series Header Instructions. Page 1, half way down, look for Checking For Water Reversion.
Sort of lays it out pretty clearly.