September 13, 2018 at 9:09 am #17296
Hi All, I purchased a 470 with low hours last year, when it arrived the engine was seized due to the previous owner running her up with a failed exhaust gasket.
the allowed water in to the pots which sat for 6 months leading to the seize.
I stripped her down and had the bores inspected and honed.
I bought new pistons and rings, mains and big end bearings for her.
The head was reworked, valve seats re cut, new stem seals, and skimmed.
I have ready to fit new cam seals OEM which is the next job before the build.
I thought I would track progress on a thread for both assistance and so it might be useful for anyone else in the future.
So the current situation is that the crank is fitted, the pistons are ready to fit, the head and sump are off the lifters are out, the cam is still in.
Time to pull the front cover so I can fit the cam seals.
Researching timing the engine before I pull the front cover and timing gears to get access to the water pump and cam seals.September 13, 2018 at 3:19 pm #17297September 13, 2018 at 7:39 pm #17300
I’m so glad you’re doing this and posting your progress (and, with pics!).
I’ll probably be a month or two behind you on a lot of it. I’m no great
mechanic and this will help me out a lot!September 13, 2018 at 11:05 pm #17301
Hey Jim I’m glad you will find it useful.
There are only a few contributors on here but what they know on the 470 is worth it’s weigjt. I’m also hoping for their guidance.September 14, 2018 at 3:33 pm #17302
Ok today’s challenge is the cam seals. Whilst the cam is ok one of the seals is jammed solid.
Even with heat applied it won’t move so I’m taking it to get pressed out by an engineering shop.
Rather that than risk damaging the casing with a hammer.September 15, 2018 at 6:13 pm #17303
When you fit the water side cam seal fit it just short (1/32″ or less) of where it should be, so if at some time down the road the front seal wears a grove in the cam you can seat the new seal on a good part of the cam by setting it to where it should actually be.— Note do the previous or not it is your choice.
Another note –be careful about putting the rod bearings in the rod, and yes there is an upper and lower bearing shell . They should be even side to side in the rod and rod cap you can assemble the engine with the bearings in wrong but won’t be able to turn it easily. You should have the merc manual when doing assembly. I have a pile of pictures and notes that I had on Photobucket before they decided to charge for their free service and before the host of this site changed and the archives disappeared.September 16, 2018 at 1:37 pm #17306
Good tips there stractor.
Regarding the location of the seals- does that apply to both or one ?
I have manual no.3 next to me.
I see the alignment of the shells and the misalignment pictures- install The new bearings centrally not offset to one side.
Just waiting for perfect seal to arrive nowSeptember 16, 2018 at 9:45 pm #17307
The rear cam seal can be seated to where it belongs, as one side is exposed to the engine oil they don’t wear as quickly. You should have a copy of Manual #8 it is for the 470 . #3 is good for things like the bearing shell picture that doesn’t show up in manual #8. I usually use #8 first and then go to Manual #3 to see if there is any other information.September 17, 2018 at 11:36 am #17308
Thanks Stractor, new seals are in.
I set the water side seal flush with the casing top. Hope that will be ok ?
Images HERESeptember 17, 2018 at 10:16 pm #17309
You had better check the orientation of the seals , from what I can see the water side seal is in backwards. Both seals should face the same direction. The rear oil side seal looks to be OK, I can see the spring inside the seal. I also looked at a spare cover that I have and your, water side, seal seems to be backwards. If there is any way you can get me your email can send pictures that I have collected. While you have access to the exhaust system you should look at the water flap valve located in the upper end of the exhaust pipe coming from the transom assembly. They are either broken or missing on most boats. It is a rubber flap that closes off the exhaust system to sea water in certain conditions.September 17, 2018 at 10:50 pm #17310
My email is email@example.com
Yeah I will certainly check the exhaust flappers.
Good job I ordered 2 sets of seals so I have another if I can’t press them out again.
The new seals have a metal side and an exposed side. I have both exposed sides facing each other as it stands.September 18, 2018 at 7:24 am #17312
Hey stractor I just read the manual and it states that both water pump seal lips face water side.
Doesn’t that mean that the lips face each other rather than point the same direction ?September 18, 2018 at 10:20 am #17313
OK I have now reversed the seal at the impeller side.
Either the new seals have a different design or we are both wrong as when I look at images of the casing the images all seem to have
a solid metal face showing outwards.
I seem to recall the old seals having a metal face either side and the new seals only one side.
the important thing is that both lips now face water side – impeller side.
Whats the use in having a seal facing the dry center anyway.September 18, 2018 at 7:36 pm #17314
Next job today was to replace the main bearings.
Old ones were OK but while its stripped down – I changed them.
I found a burr on the crank – needle filed it down and buffed with 200 then 320 then 400 grade emery.
Lubed with oil and the crank spins nice.September 20, 2018 at 4:32 am #17315
Another note— The consensus around here, when the board was in full swing, was to use a Mercruiser brand head gasket.
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