Problems with first rebuild

[Walt T]

Re: Can you verify roller or flat tappet lifters from this photo?

Re: Can you verify roller or flat tappet lifters from this photo?

Okay you need to tape off the intake and exhaust ports to keep dust and debris out for gods sake cover that bottom end. Stick the oil pan on with just the four corner bolts finger tight. You accidentally bump that pickup and loosen it you'll discover it when you see 4 foot swells coming at you and a line of black clouds pushing it.
The valley, water ports, and any open oil holes have to be covered too or wrap that engine up good. That is not a clean environment which is critical to engine longevity. The life of that long block starts with how clean it was during assembly. Keep the ports taped off until just before you install manifolds. I suggest plasti-gauging the bearings and verifying torque on the bottom end and heads but its probably safe to assume it's all done pretty good since the builder has to warranty it. I have indeed found bearings already scored, broken connecting rod bolts, broken piston rings, loose main cap bolts, and loose head bolts on fresh built long blocks from suppliers. However this is over 40 years and its less than 15 engines.

Use proper specifications for your specific carburetor and setup. NHguy may be correct but verify it just like I suggested to verify the engine assembly.

 

[wrench 3]

Re: Problems with first rebuild

NHGuy's adjustment method is the same as in the GM manual, and they built the engine. The best way to tell if you have zero lash, is to try to spin the push rod between you thumb and finger. At the point when you can no longer spin it, start counting the turn on the adjuster nut.
It is very unlikely that you could see the type of lifters with only the valve covers off. The difference is at the bottom of the lifter were it rides on the cam lobe. Can you remember what the engine looked like before you installed the intake manifold. Were the lifters just dropped into holes in the block or were they held in with metal plates bolted into the block. Flat bottom lifters just drop in, but roller lifters have plates to stop them from rotating in the block.
You are not going to get a good compression reading until you get the engine running to get oil on the cylinder walls and rings. If you put oil in through the spark plug holes, you will get a false high reading. I'd be happy with 125psi.
Btw, a professional re-builder would have used an assembly lub that would have helped protect the cam and bearings.

 

[nothingspecial]

Re: Problems with first rebuild

Ahoy! everyone and thank you for all the response. Here is another update on the rebuild. While I was waiting for the new fuel pump I pulled the valve covers and attempted to adjust the valves. The tension nut was set about 4 threads down on all before I began. I was expecting them to be "too tight" causing low compression readings. Before I pulled out a wrench I was able to spin 13 out of 16 push rods with my fingers. And went ahead with an adjustment anyway. I used the method as described in manual with engine off. I loosened nut about two full turns and tightened about a half turn past no lash. After several minutes the push rods would spin again-- confused on why--- Maybe without motor running the lifters can't "pump up" and stay tight ?? I did all of them twice and had same results but now all nuts are down about 3 threads from top. I'm thinking I may need to do it messy--with motor running to keep lifters pumped up to get correct adjustment. I do not know if I have solid or hydraulic lifters. Assuming hydraulic, if my "pump up" theory is accurate. I would appreciate some feed back on this matter. Can I pull one valve cover at a time with motor running? how much oil will I loose with no cover? It makes more sense to me to do it running so I can hear the lash and then remove with half turn more. There seems to be a lot of variation on how tight is right. Some say quarter to half is better than the full turn the manual says. Anyone?

Ok, I installed a new fuel pump today. I found some Lucas break in oil SAE 20 I put in 6 quarts and a new filter. Motor is on run stand and ready for "RE-break-in". Set my timer for 30 minutes and fired her up. I ran it for about 7 minutes straight between 2000-3000 rpm. It died out on me because there is no choke on it right now. I will come back to choke dilemma. Let it cool about 30-45 seconds and ran it again for about 11 minutes straight at 1800-3000 rpms. Choke again. Let it cool about a minute and ran it again for about 10 minutes straight from 1800-3000 rpms. It seemed to run strong and sounded decent when I had manually adjusted choke and throttle correctly. As I would manually move choke too far open it would back fire -- and get rough. I could smooth it out as i increased throttle and adjusted choke accordingly. I had one hand on throttle and the other on choke for the entire 28 minutes. It would have died out if I would let it idle below 1500 rpm. But I kept it running hard the whole time with those two "kills" I put in a 160 degree thermostat and held that temp almost the whole time. The backfiring? Not able to idle? Could this be valves? Timing? Carb ? Choke? could be one or all-right? I had timing originally set to 8 btdc but I was playing with it a while ago and think it is now at 0 tdc. I stopped playing with it when I discovered the fuel in my oil. Does any one know best setting for advance or is each motor different and needs to be set according to its own "curve"?

I am planning on doing timing again after the "break in". I would like some feedback on my choke issue. The boat originally had an intake manifold stove top choke. I had trouble with a working replacement and am considering a conversion to an electric choke. *** Please advise ****

I only noticed a little bit of fuel mixed with the exhaust water running down my driveway. Not as much as before. I could not tell if there was any white smoke on account of temperature. I live next to Chicago and it was about 10 degrees today. below zreo with wind chill. I had a lot of steam!! but it dissipated quickly and did not smell like before.

I brought motor back into garage and did a compression test with break in oil and engine still warm. All plugs out. Throttle wide open. Drum roll......

1-155 psi. held 150-not much leak down
2-160 psi. slow leak down
3-155 psi. very slow leak down
4- 165 psi. very,very slow leak down
5- 165 psi. holds well
6- 160 psi. holds well
7- 160 psi. holds well
8- 160 psi. slow leak down

I don't know how to perform a proper leak down test.

The spark plugs looked much better this time. A little black on outer circle and brown on tip.

I drained oil to look for metal and fuel. No metal a very little amount of fuel. Oil did not smell like fuel maybe fuel is from a carb issue??? maybe valves??? backfiring??

I put a new oil filter on and 6 fresh quarts of valvoline 20-50 vr1 racing oil in and old plugs. I am waiting on all of your great advice to continue. Thanks again

 

[NHGuy]

Re: Problems with first rebuild

You just did your cam run in, good. 160 compression basically across the board, Yippee!
With a warm motor and starting out at 8 degrees btdc at idle you'll get up in the upper 20's of advance at 2000 rpms. So next time you start it try to get it to idle and set it to 8 or 12 degrees at 650 rpm. Even if it's not fully warm you want that 8 to 12 degrees. Then see if you can open the choke when it's warm.
A few things to check, see that all the manifold bolts are snug, and that the carb bolts are too. Spray some carb cleaner around the base and pivot shafts on the outside of the carb. Also spray it around the perimeter of the intake manifold, especially where it contacts the heads on the sides. If you get an increase in RPM when you spray the carb cleaner there's a leak there. Any carb or intake leaks defeat the fuel mixing of the carb, so fix them next if there are any.
Once you know the carb and manifold are tight tell us whether you can open the choke.

Just do the valve adjustment like it says, put the rotor at #1 TCD and #6 TDC, do your lash..once the lash is gone turn them all the same amount, you are supposed to turn em 1 full turn from zero lash. Half a turn is a move that some guys make to be sure the valves close tightly. Since the book says to turn them a full turn from zero lash, that could be why the lifters loosen after a while. Just do it either way and leave them there.
Those are hydraulic flat tappet lifters. Hydraulic is oil filled, not solid. And flat tappets are smooth faced against your cam, they don't have rollers.

Oh, and drain out your block unless that motor is in a heated space, water in the block will freeze and ruin the engine!
Go pull the drains now, it's freezing out!

 

[nothingspecial]

Re: Problems with first rebuild

I put all new hoses on the motor. One of the hoses was different than what I ordered. At first I was upset of the change but now am very happy for the upgrade. The hose that connects the thermostat housing unit and the water circulating pump has a drain plug at lowest point. This drains all the water out of the block. My garage is only heated when I am out there so I am very thankful for this new style hose--Genius

 

[FreeBeeTony]

Re: Problems with first rebuild

Not sure I would trust that hose........there s/b 1 drain on each side of the block.

 

[81 Checkmate]

Re: Problems with first rebuild

Im thinking the block drains are alot lower than the water pump hose drain. Not sure...never seen a hose like that.
Id say after watching the game last night and it was 16 deg......if your block has water in it....ist's gota crack in it now.


Hope im wrong!

 

[nothingspecial]

Re: Problems with first rebuild

My Garage never got down below freezing point last night which is good because I don't know what/where the s/b 1 drains are on the block. I never noticed them- but , I wasn't looking for them either. I'll take a look. Only water should come out right?

 

[nothingspecial]

Re: Problems with first rebuild

I've located two plugs? they are about centered on each side of block near bottom(just above oil pan) They have a hex tool style head. Are these the s/b 1's? and are these plugs left open during "normal winterization"? Sorry-This is my first boat

 

[FreeBeeTony]

Re: Problems with first rebuild

yes, I would remove them, stick a wire hanger in there to clear the passage, let the water drain out and, leave them out till the spring........

 

[wrench 3]

Re: Problems with first rebuild

I used to leave the drain plugs out over the winter but had trouble with the threads in the engine rusting. After having to oversize and re-tap a couple, I started putting them back in and adding some antifreeze.
On a "V" engine you have to remove the block drains and remove the hose from the pump, to drain the pump. (plus drain all the marine add ons) The drain on the hose saves you from taking it off.
The lifters may bleed back down, but it won't affect the adjustments. When you back of the adjuster nuts the lifters "pumps back up".
If you try to run it with a valve cover off, you and everything around you will be covered with oil. If you do want to set it running, place rags over the push rod end of the rocker arms. It won't stop all of the mess but will help.
Unless you have an open PCV port or something, your idle problem sounds like a carburator problem.
BTW do you have the marine exhaust manifolds, oil cooler or water supply pump on it. If so they need to be drained.

 

[Silvertip]

Re: Problems with first rebuild

You should not have to mess with the choke on an engine that has been running for more than a few minutes. The choke plate by then should be standing perfectly vertical. You NEVER adjust a choke on a warm engine. You adjust it on a stone cold engine so the choke plate just barely closes. You do not have solid lifters. If you did the adjustments couldn't have changed as you indicated.

 

[81 Checkmate]

Re: Problems with first rebuild

Hope you caught the drain plugs in time.....Thats a good thing.

Go to the hardware store and get some solid brass plugs......
Im with silvertip, you have carb issues...if you have to keep the choke plate almost closed after 20 min run then its not right. Id have the carb rebuilt or rebuild it myself while waiting for warmer weather to fire it back up.

Heck i have my choke plate wired full open for now untill i get an electric set up. It starts alittle ruff but when it warms up in a few it runs good and smothes out......It's not like im starting it in the dead cold of winter all the time and i dont boat unless it's above 70 deg. I may go with an manual choke cable for now.

Good Luck!

 

[CharlieB]

Re: Problems with first rebuild

1st posting I noted he has a fresh recon carb. Did it come with the boat or did you buy it? If you recently bought it perhaps the seller will agree to exchange for an electric choke model if you pay the difference.

s/b was shorthand for 'should be' 1 drain plug on each side of the lock, you found those. The water cooled exhaust manifolds also each have a drain plug on the bottom.

Depending on how the exhaust manifold water is plumbed, the risers can also have a drain plug in the lower side.

Every drain plug can accumulate rust inside the hole and block water from draining out completely, always use a wire, nail, small pocket screwdriver to poke inside, making sure the passage is clear so the water can drain freely.

The lower water pump hose must be drained, also any oil cooler that may be in-line with the feed water hose.


You've done quite well for a beginner. Keep asking questions to be sure you understand the what's and why's and you're boat should begin shaping up quite nicely.

 

[Boomyal]

Re: Problems with first rebuild

.......Every drain plug can accumulate rust inside the hole and block water from draining out completely, always use a wire, nail, small pocket screwdriver to poke inside, making sure the passage is clear so the water can drain freely.......

I can attest to that!

 

[nothingspecial]

Re: Problems with first rebuild

Thanks a million!! you were right - That hose with drain plug is just for thermostat and pump. I removed the s/b 1's and got more water out of block. I cant get the big drain plugs loose on the exhaust manifolds yet. So I will try and keep my garage above freezing.

 

[nothingspecial]

Re: Problems with first rebuild

Any thoughts on what type of choke is more reliable? electric or manifold stove top ?

 

[NHGuy]

Re: Problems with first rebuild

If you are trying to pull the plugs out of the bottoms of the exhaust manifolds, don't bother. Just pull the hoses and the water will fall out. Also don't forget to pull one of the water hoses off the power steering cooler that's on the port side of the engine. And lower the drive to let it drain out, you don't want water trapped in the bottom of the drive where it can freeze and break stuff.

 

[wrench 3]

Re: Problems with first rebuild

Thanks a million!! you were right - That hose with drain plug is just for thermostat and pump. I removed the s/b 1's and got more water out of block. I cant get the big drain plugs loose on the exhaust manifolds yet. So I will try and keep my garage above freezing.

The drain plug in the exhaust manifold will be ruffly the same size as those in the engine. But as NHGuy said, if the hoses are on the bottom or very bottom corner, they can be used to drain the manifolds.
Did I miss it, or what make and model drive are you working with?
Never mind the make. we're in the Mercruiser forum. But is it an alpha or pre alpha?

 

[FreeBeeTony]

Re: Problems with first rebuild

Thanks a million!! you were right - That hose with drain plug is just for thermostat and pump. I removed the s/b 1's and got more water out of block.

Glad I could help!!!