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hi all

sundowner 206 volvo 5.0ltr gl with holly carb

does anybody know were the other end vent hose from the crank case should be fitted, one of mine is connected to the air filter, the other one was connected to the carb. engine has not been running, no power when warmed up. the local volvo dealership have disconnected the one from the carb and now it runs perfect, but they do not know where the end of the vent pipe should be connected, there is no fitting on the air filter like the one on the other side coming from the other crankcase. at the moment it is shoved under the flash arrestor.

also is it true when you fit a new starter motor does it has to be set up with shimms so the bendix gear lines up with the flywheel, it has just sheered off the a bolt for the second time and the engine has got to come out again because the thread is still in the block.

martin

not sure about the holley carb but most marine engines have two hoses for blow by vapors...one from each valve cover going to the flame arrestor....does your engine have a PVC valve as well...most older ones don't....
On older marine engines these vapors are just vented to the flame arrestor but on auto engines they have used a PVC valve to burn the vapors since the early 60s..

About the starter...maybe they did not use the right bolts or didn't tighten them enough...I replaced the starter on my 4.3 and did not have to use any shims...

_________________
88 Four Winns 200 Horizon
4.3 OMC Cobra-4bbl
2002 Walker Bay 10/2012 Suzuki 2.5
2008 Walker Bay 8

1998 Jeep Grand Cherokee 4.0/Selectrac
2007 Jeep Grand Cherokee 5.7 Hemi/Quadradrive II

not sure what a PVC valve is or what it would look like, the basic engine is a GM small block V8 i am told which volvo then alter for use in boats, the boat was built in 2000.

the bolts that were used were second hand, i only found that out today after it had sheered off, the volvo dealership said the bolts were 8.1 and they should have been 12.9, the figures relate to the tensile strenght of the bolt.

Re the starter, using shims to ensure the gear alignment would seem very odd. If the bolts were 8.1 ( pretty standard bolts you'd buy in B&Q etc) and were torqued to the spec for much higher grade bolts (they probably meant 10.9), thay were probably strained well beyond their elastic limit. It was only luck they didn't break off when they were being torqued up, twisting force from the starter operating would have pushed them over the edge.

As for the breather hoses, I've only had EFI engines. On those, (1999 and 2004 engines) there was only one breather hose from the starboard rocker cover which went to the side of the flame arrestor. I can check this weekend if the port rocker cover has a blanked off hole, I don't think it does ( Oil fill cap is on the starboard rocker cover, so the covers are different)

Where does the other still attached end of the second hose go to ? Where did it attach to the carb? ; is that point of attachment to the carb now open to the atmosphere?

Graham

the hose in question is on the starboard rocker cover where the oil filler cap is, this end is still attached, the connection on the carb has been blanked off and the hose has been tucked under the flash arrestor.

apparently the bolts were supposed to have come off a merc engine, they were not in good shape and the surfaces were pitted.

it was connected to the base of the carb on the starboard side, i have seen this set up on a 2000 montery, it had a volvo 5.0 i, not sure what the (i) stands for, it had a different carb fitted, apart from the base engine most of the ancillary equipment fuel pump etc was different. his engine worked fine except for the fact it had started overheating and his mechanic ( the same one i employed to repair the starter motor the first time the bolt sheered) cannot find out why?

The Monterey may well have had a fuel injected 5.0 (5.0 Gi). In 2000 it would have been throttle body injection, it basically looks like a carb but with 2 injectors in it. The other ancillaries would have been the low pressure + high pressure pump assembly, rather than the low pressure pump found on a carbed engine.

At the rocker cover end there is usually a PCV, which controls the ammount of crankcase fumes that reach the inlet. I am still not 100% certain of what hoses you have though:
Hose to flame arrestor: where does the other end of it go?
Disconnected hose from PCV/ starboard rocker cover to base of carburretor. Could there have been a split somewhere in that hose, allowing in air?

Graham

graham

the hose that was already on the flash arrestor, the other end is connected to a black plastic elbow on the rocker cover (port side)

it has the same arrangement on the starboard side except the hose was connected to the base of the carb, it is now under the flash arrestor.

when i took delivery of the boat the mechanic that originally serviced the engine came out and fitted a new black plastic elbow to the starboard rocker cover, i had complained the engine was not running right, the old elbow was split and he had taped it up with electrcial tape, he said apart from the petrol this was also causing the engine to run rough, after he fitted this elbow it got alot worse and then i started having real problems as i have detailed before.

basically i have the same set up on both rocker covers, two black elbows with two hoses, both are now under the flash arrestor and according to the skipper who sea tested it on Tuesday it goes like a rocket, top speed he recorded 49mph at 5000 rpm, i have never had above 3800, and it only got to 3800 once, before he replaced the broken elbow. there were no splits in the hoses.

unfortunatley i am unable to verify this because when i tried to take it out the starter motor sheered off. i must admit i am getting very wary of marine mechanics, the firm who has done the work recently and are doing the starter motor are a major volvo franchise and although they are very expensive they are making progress, but even they are not sure where this hose should be connected, carb or flash arrestor, all we know is it runs properly when not connected to the carb.

its interesting what you said about the monterey, i went to see the mechanic who removed the engine and fitted the new bolts to the starter motor, to inform him that the incorrect bolts had been fitted, he basically replied a bolt is a bolt, meaning the strenght of the bolt is irrelevant, there all the same. anyway he was trying to convince me there was something else seriously wrong with my engine and the volvo franchise was taking me for a ride. he said my engine had never started first time from cold, which is true it normallys start on the second or third attempt, which i understand to be normal with a carb engine, hot it starts first time everytime. he said the monterey had the exact same engine, he even showed me the engine in the boat, i told him it was not the same engine and due to the fact it had 5.0i on the flash arrestor i thought it was not even a carb engine, he pointed to what i believe was the throttle body from your discription and said that it was a carb and i did not know what i was talking about, or words to that effect.i think the owner of the monterey is going to have a bit of a time of it, i feel as though i should warn him but usually people do not appreciate that kind of intervention.

Honestly I would not trust these guys if they are a Volvo shop they should know EXACTLY how those hoses are set up...don't they open a shop manual and look at the schematics as to how things are set up? As a pretty good do it yourselfer I'd have no patience with that kind of work and get a Volvo manual and do it myself...which is what I've been doing for 37 years myself....if you have time go over to http://www.dougrussell.com and look in the volvo parts section...look at the fuel system diagrams maybe it's there....

_________________
88 Four Winns 200 Horizon
4.3 OMC Cobra-4bbl
2002 Walker Bay 10/2012 Suzuki 2.5
2008 Walker Bay 8

1998 Jeep Grand Cherokee 4.0/Selectrac
2007 Jeep Grand Cherokee 5.7 Hemi/Quadradrive II

Martin,

I found this explanation of why a PCV is fitted.

The blowby vapors that end up in an engine's crankcase contain moisture as well as combustion byproducts and unburned fuel vapors. The crankcase is sealed to prevent the escape of these gases into the atmosphere, but the vapors must be removed to prevent oil contamination that leads to sludge formation. The positive crankcase ventilation (PCV) system siphons these vapors from the crankcase and routes them into the intake manifold so they can be reburned in the engine.

The main component in the PCV system is the PCV valve, which is usually located in the valve cover. A hose connects the PCV valve to the intake manifold. A second hose between the air cleaner and crankcase or other valve cover (V6 or V8 applications) provides fresh air to help flush the vapors out of the crankcase.

Is there a PCV fitted, or are they both just elbows ( externally they would look quite similar). If there was no PCV fitted in the hose that was fitted to the base of the carb, presumably a lot of air would be reaching the carb/ ionlet manifold.

I will have a look at the hose set up on my engine tomorrow, it's EFI not carb, so certain things will be different, but the principle should be the same.

As to a bolt is a bolt very worrying. To give an example (from when I recently fitted a towbar to my car):

M12x1.75, 8.1 grade bolt : recommended torque 95N/m

M12x1.75, 10.9 grade bolt : recommended torque 139 N/m ( 46% higher; this torque would be almost certain to break or strip the thread on a 8.1 bolt/ nut!)

Graham

graham

the flywheel had 30 teeth missing, a new gear ring has been ordered, that should resolve my problems with the starter motor. they also found a salt water leak on the exhaust, both the leak and the missing teeth had been there for quite some time, years not months. hence the reason the boat had not been in the water for over two years. there's a lesson here, to late for me, if anybody is considering buying a boat that has been laid up for more than one season a full boat survey and a sea trial may not be enough. i talked to the previous owner and they said the only reason it had not been used was because they didn'y have the time. given the condition of the flywheel this was obviously not true, the service manager said he has seen this type of damage before and it is nearly always caused by putting the incorrect (cheaper) starter motor on when the old one packs up.

the service manager confirmed the elbow on the starboard rocker cover, which was connected to the carb, is just an elbow made of black plastic. the one on the port side is a PCV made of black plastic. i managed to get a look at an identical engine that was fitted in a boat last year. the port side PCV is black plastic and connected to the air filter. the starboard side has a black plastic tube rising vertically, about 35mm, from the rocker cover, the elbow is made of metal, looks like stainless steel, and incorperates the PCV. the hose is connected to the rear of the carb at the base just above the transition plate on the inlet manifold. it would seem the downside to leaving it venting to atmosphere is that there would be more vapours entering the engine bay. my initial thought was to leave it alone, as the engine is now working properly, but i may do a bit more digging and see if i can get a replacement metal PCV and put it back as it is on the other engine and see what happens.

Lou C

thanks for the info, i had a look but the detail was not there. i appreciate what your saying, i do not know what the situation is over there, but the service manager at the dealership tells me the problem is they very rarely see a petrol carb engine. 80% of their work is on diesels, the remainder is fuel injected. the mechanics seem to be either merc or volvo, they are not keen on jumping from one to the other, although the base engines are the same there are differances, so i am told.

the guy next to me in the marina only works on volvo GM based engines, i would have asked him to have a look, but he is booked up to christmas.

the mechanic who is doing the work does have experiance of this engine, although he has not worked on one for a few years, that is the price of progress i suppose?

Hi Martin
I guess being that I grew up in the golden age of musclecars here in the USA it's hard to imagine any mechanic over the age of 40 who is not familiar with a carburated Chevy V-8...there were literally millions of them made powering everything from family cars...cop cars...taxis...hot rods and boats...
Anyway the way a PVC (positive crankcase ventilation) system is usually plumbed is as you thought....there is a pvc valve in one valve cover...the hose from it has to go to a vaccum source like a fitting on the base of the carb or intake manifold...and there is another plastic fitting in the other valve cover with a hose attached that should go to the flame arrestor...basically the way it works is the vacuum from the carb pulls open the valve and that allows blow-by vapors from the crankcase to be burned in the carb...the hose on the other valve cover allows air to be drawn to take the place of the fumes sucked by vaccum.
The things that can go wrong...are if the hose does not fit right it can cause a vaccum leak that will cause it to idle poorly...I used to replace these valves at tune up time...
Mine does not have a PVC...just a plastic elbow on each valve cover and a hose to each side of the flame arrestor...

_________________
88 Four Winns 200 Horizon
4.3 OMC Cobra-4bbl
2002 Walker Bay 10/2012 Suzuki 2.5
2008 Walker Bay 8

1998 Jeep Grand Cherokee 4.0/Selectrac
2007 Jeep Grand Cherokee 5.7 Hemi/Quadradrive II

hi Lou C

if it wasn't for forums like this one, those of us with old technology would be in a world of trouble, thanks for the info, at least now i understand the process behind it.

by the way, i lived in toronto for a couple of years back in the 80's, i had an old chevy van which i used for work. when i bought the van i was amazed to find a V8 under the bonnet, at that time in the UK the only vehicles with V8 were Aston Martins & Jags etc. the largest engine we ever had in a van over here was a V6 made by Ford and then know one bought it because it used to much petrol.

anyway thanks again

martin