Perkins 4-108 starting in cold vs warm state

[doog]

Looking into the fuel pump timing, the three bolts on the pump to the case are controlling the same geometry as the three bolts on the drive gear under the timing cover, so its the same adjustment/different fasteners. But the timing is good. Lots of good comments here and Im getting the shell Rotella out and replacing with Delo now that the engine is in daily use, so glad someone shared their experience damaging a marine volvo installation from the use of synthetics on a chat about ZDP friction additives. And yes I have the little pre-heat system on the intake but its never been needed. Maybe worth giving that a try if its a more efficient use of amps than cranking the starter.

[skipperpete]

Originally Posted by doog

Looking into the fuel pump timing, the three bolts on the pump to the case are controlling the same geometry as the three bolts on the drive gear under the timing cover, so its the same adjustment/different fasteners. But the timing is good. Lots of good comments here and Im getting the shell Rotella out and replacing with Delo now that the engine is in daily use, so glad someone shared their experience damaging a marine volvo installation from the use of synthetics on a chat about ZDP friction additives. And yes I have the little pre-heat system on the intake but its never been needed. Maybe worth giving that a try if its a more efficient use of amps than cranking the starter.

I can’t think of any reason why synthetic oil would be related to your starting problem but it’s probably good that you’re changing it if you did the rings and pistons in your overhaul, I only like to use mineral oil in rebuilds until at least the first oil change ......and with anti friction additives, even longer. Give the rings time to settle in and seal properly. I’m wary of putting additives in engine oil BUT I do use “Liqui moly Mos2” in my 4wd engine. Engine parts, mostly camshafts and pistons were once subjected to a factory treatment called Molybonding which actually worked quite well but it’s seemingly gone as an industrial automotive process these days. I know only what Google says about ZDP and it sounds like the usual sales hype.

[doog]

I agree that the oil installed does not directly affect the start-up difficulty, not until the compression is damaged anyway! (not sure how many hours I put on with that oil, 10 or 20 charging batteries) I've got the good old Delo 400 back in the engine again and feeling much better about that. Good to have these other points in mind as well about timing and the return valves in the fuel system.
Its just so dramatic how instantly the engine starts when warm, just a tap on the starter. But if its cold one wonders if the battery will hold long enough to get the job done! Then it catches roughly and finally takes off in a cloud of smoke.
Thanks everyone for the great info.

[Searles]

Yes you can now get 12 volt hair dryers , the original pre heat in the air inlet works well with little maintenance,however I like winding the engine over a few times before firing as it raises the oil pressure preventing a dry start ,may result in a puff of exhaust smoke on start up ,just another trick .⛵️

[doog]

https://www.cruisersforum.com/forums...-245868-3.html

I found this very thorough discussion on the issue often found with this and other engines and the issue of fuel pressure. This relates to the check valves in the system and in the case of this discussion it was addressed with electric lift pumps which I also used in the past, not for starting but to prevent air leaks causing fuel starvation. But now I have a gravity feed tank so Ive not used the electric pump and Ive been warned against them because of the risk of putting fuel into the oil past the pump seals into the crankcase. But just for cold starts maybe I'll try the lift pump again.
Clearly the check valves are critical and a good idea to make sure they are working properly because one only has so much battery available and all that cranking can be really hard on starter motors and the wiring. Not everything in the discussion found at this link here above is correct by any means but they shared a great deal of really useful information.

[rbk]

Originally Posted by doog

https://www.cruisersforum.com/forums...-245868-3.html

I found this very thorough discussion on the issue often found with this and other engines and the issue of fuel pressure. This relates to the check valves in the system and in the case of this discussion it was addressed with electric lift pumps which I also used in the past, not for starting but to prevent air leaks causing fuel starvation. But now I have a gravity feed tank so Ive not used the electric pump and Ive been warned against them because of the risk of putting fuel into the oil past the pump seals into the crankcase. But just for cold starts maybe I'll try the lift pump again.
Clearly the check valves are critical and a good idea to make sure they are working properly because one only has so much battery available and all that cranking can be really hard on starter motors and the wiring. Not everything in the discussion found at this link here above is correct by any means but they shared a great deal of really useful information.

Use a low pressure solid state in line pump (also great for bleeding). Virtually impossible to wreck the lift pump or blow seals. I bought a second one for a transfer pump setup a couple years ago and it was around $50. Also acts as a backup lift pump should the one on the engine fail.

[doog]

Yes rbk, this is what I have installed on a breaker-switch. Yep, I also picked up a second for various uses such as oil changes. Good to hear it can't cause fuel to get into the oil.

[doog]

To complete the details, I tried using the electric fuel pump on starting when cold and it may have helped a little, but pretty much the usual hearty cranking needed. Today this AM I ran the 110-degree output of the diesel heater into the engine compartment for 15 minutes and the start was very prompt after a couple seconds of starter on a 11.8 volt battery which was low from overnight discharging on my off grid setup. (would normally be inadequate to get a start) And indeed the engine sounds so much happier on Delo 400 than it did on the Rotella T-6. Its about 40 degrees and the boat is unheated overnight, Probably about 50 in the engine compartment. I like the idea of the cordless blow dryer but it just takes too much power to make heat for this to be practical and one could use the boat inverter and batteries with a heat-gun, but seeing how even a toaster pulls down the voltage, or a heat gun, no. You need fire to make the needed substantial level of heat. A propane system would probably work great as pre-heater and I see them for sale for diesel trucks, but potentially dangerous and complex unless it was a furnace with the flame removed from the engine compartment.
Im sold on use of the CDH to preheat the engine in winter conditions.

[Celestialsailor]

I have had a few 107s and 108s and you mentioned your battery being low. These engines really like higher voltage and available amps. maybe combine your house and starting battery or replace the starting battery with a new, higher amp battery.

[rbk]

Originally Posted by doog

To complete the details, I tried using the electric fuel pump on starting when cold and it may have helped a little, but pretty much the usual hearty cranking needed. Today this AM I ran the 110-degree output of the diesel heater into the engine compartment for 15 minutes and the start was very prompt after a couple seconds of starter on a 11.8 volt battery which was low from overnight discharging on my off grid setup. (would normally be inadequate to get a start) And indeed the engine sounds so much happier on Delo 400 than it did on the Rotella T-6. Its about 40 degrees and the boat is unheated overnight, Probably about 50 in the engine compartment. I like the idea of the cordless blow dryer but it just takes too much power to make heat for this to be practical and one could use the boat inverter and batteries with a heat-gun, but seeing how even a toaster pulls down the voltage, or a heat gun, no. You need fire to make the needed substantial level of heat. A propane system would probably work great as pre-heater and I see them for sale for diesel trucks, but potentially dangerous and complex unless it was a furnace with the flame removed from the engine compartment.
Im sold on use of the CDH to preheat the engine in winter conditions.

I wouldn’t expect the in line pump to help any with a cold start unless your lift pump was toast. Sounds like you really need a dedicated start battery first off. If you’ve already got the diesel heater great, if not and you need a temp solution a cheap propane torch will do the trick (they are handy for many reasons I keep mine alongside my propane tank in the propane locker).

[doog]

I do have a dedicated start-battery and this work started with the massive old delco starter pulling so much current that it melted a battery terminal on the cable. Probably a bad soldier joint. And this led to installing the gear-driven starter that is smaller and lighter and uses much less juice. One thing led to another and I ended up pulling the head and doing the valves..
These starters are cheap and work great. But indeed, it still requires a hefty crank even with this, and with the Chinese diesel heater ducted into the engine box for 15 minutes, that really did the trick. Of course I have a propane torch handy but I tried that and heated the manifold below the intake and also the cylinder head a little, and it seemed to make little difference.
15 min of 110 degree air into the small engine box and it just fired up wonderfully with a very brief crank with a battery at less than 12 volts.

[CSY Man]

OP: Do you start the 4-108 with the throttle in the idle position?
if you do, try to crack the throttle and the engine may start easier.
It worked on my 4-108.

[rbk]

Originally Posted by doog

I do have a dedicated start-battery and this work started with the massive old delco starter pulling so much current that it melted a battery terminal on the cable. Probably a bad soldier joint. And this led to installing the gear-driven starter that is smaller and lighter and uses much less juice. One thing led to another and I ended up pulling the head and doing the valves..
These starters are cheap and work great. But indeed, it still requires a hefty crank even with this, and with the Chinese diesel heater ducted into the engine box for 15 minutes, that really did the trick. Of course I have a propane torch handy but I tried that and heated the manifold below the intake and also the cylinder head a little, and it seemed to make little difference.
15 min of 110 degree air into the small engine box and it just fired up wonderfully with a very brief crank with a battery at less than 12 volts.

I also replaced my direct drive starter but not with a cheap Chinese one. Not sure I understand your setup; If you have a dedicated start battery, why was it reduced to 11.8V overnight 'due to your off gird setup..'? A dedicated start battery should have no other draw other than starting? Maybe I'm missing something.

Use the torch on the intake, don't bother trying to heat the head or the block with it. Putting flame directly into the intake while starting is the exact same principle as the thermostart mechanism, draw warm air into the cylinders.

If you had the engine running the previous evening/day before shutting down there is a significant amount of residual heat in the block already and will help in starting. If you were to leave it for a few days you may notice it harder to start again even when running the heater and may need to run the heater overnight into the engine compartment. I've done this on potentially really cold starts dockside with a space heater.

[doog]

rbk- Missing something? most def. so, But its not about batteries!

[Baby tug]

There’s million ways to heat your engine , they make a whole variety of different devices block heaters and the like , Some go in to cooling water some stick to the bottom of your oil pan , propane torch like the other guy said , a million different ways of doing that , I’ve even heard of people using propane in the intake , WD-40 ,40° it’s not that cold it shouldn’t really be all that hard to start carrying an extra battery with you I don’t see the big dilemma