ongoing overheating progress

[mrxitmt]

Well , as you know , I went all the way to the short block , so , if no damage was done to the rings or bearings I should come out of this with a running engine. So far I have the heads on the exhaust manifolds and the intake .. all properly torqued.The distributer is in and lined up. so I will prime the oil before attempting to start it . Can I just unhook the coil wire and crank it ? I have only to put the elbows on and the spark plugs in and hope it starts then set the timing and maybe adjust the valves. I sure hope all this work is worth it.

I want to thank Mike for his knowledge and support and for stopping by for a look see!

I hope to be running this weekend...

Thank you all

Rick

[pascavone]

i would suggest running the engine for the first time with the manifold cooling hoses dropped off, for the first couple of minutes, to make sure you did catch all your water leaks.

Then check oil.

Then if OK, connect the manifold raw water lines.

[mmwjr]

Rick, yes you can unhook the coil wire to crank the engine over. Older electronic modules didn't like not having a load and could be damaged. If you feel unsure leave the coil wire on the coil and install a spark plug on the other end then ground the threaded portion with a jumper cable. Remember this will generate a spark so make sure no gas fumes are present.

Valves should be adjusted before trying to start. I don't believe this engine would result in valve/piston interference but improper adjustment will run like crap if at all. Just went through this with a co-worker. But he did it with the distributor 180 out so his valves were way off.

Getting closer! good luck.

[mrxitmt]

OK I can't find it in my shop manual ...How does one adjust the lash on these motors

Valves should be adjusted before trying to start. I don't believe this engine would result in valve/piston interference but improper adjustment will run like crap if at all. Just went through this with a co-worker. But he did it with the distributor 180 out so his valves were way off.

Getting closer! good luck.[/QUOTE]

[mmwjr]

I'll need to look this up myself but if I recall it's basically torquing the rockers. The key is that you need to rotate the engine so the vavles are closed when doing so. it's goes something like this. Start at TDC (top dead center) torque #1's valves, then cylinder # intake, # exhaust. Rotate engine 270 degress then torque cylinder # intake, # exhaust, rotate X degrees, ...

let me read a little tonight and get back. maybe some else knows off the top of there head like ss3964spd as he's a GM man :-)

[mmwjr]

OK look at my merc manual and oddly enough it just says adjust the vavles with no proceedure. I have a few other books that I'll need to dig through. I did find this proceedure online which is in line with what I remember, hopefully ss3964spd can clairfy.

1. Turn engine to TDC.
2. Adjust intake rockers on #1, #2, #5, #7.
3. Adjust exhaust rockers on #1, #3, #4, #8.
4. Rotate engine ONE turn (BDC).
5. Adjust intake rockers on #3, #4, #6, #8.
6. Adjust exhaust rockers on #2, #5, #6, #7.

Turn the nut to where the pushrod has resistance when spinning, then an additional 1/2 turn.

[ss3964spd]

Since I was paged......

Rick, Adjusting the valves correctly requires that the lifters are completely on the base circle of the camshaft. If a lifter is on the opening or closing ramps of the cam lobe it won't work. Yes, you can follow the sequence Mike posted above but remember the sequence starts with #1 at TDC on the compression stroke. If you rotate the crank one revolution the piston for #1 will be at TDC again, but on the intake stroke because the cam rotates at 1/2 crank speed.

I actually prefer this fool proof method, called EO-IC. Instead of typing it all out I refer you to this article: http://www.chevyhiperformance.com/te...g_valves_info/

EO-IC is a little more time consuming but you cannot go wrong. The only thing you really need to keep in mind is which valve is the intake and which is the exhaust. On a small block Chevy they do not simply alternate E-I, E-I, E-I, E-I. they go E-I, I-E, E-I, I-E.

The lifters have seats that the end of the push rod sits in and those seats are spring loaded with relatively whimpy springs. Therefore, spinning the push rod to get to zero lash (before setting pre-load) isn't always accurate because the PR will likely spin easily even with preload (you'll see what I mean after you get one set). I set mine by jiggling the PR's up and down. In other words, back off the adjusting nut until you can jiggle the PR up and down between the lifter seat and the rocker arm pocket. Then slowly tighten the adjusting nut until you just take up all the slack. That'll be zero lash. Once you feel good you've got it at zero give the adjusting nut another 1/2 to 3/4 of a turn (If you're using factory Merc lifters the manual will specify how much to turn the nut after zero lash). You're done with that one, go do the next. Hydraulic lifters are pretty forgiving, as they are designed to adjust for small variances, so don't frett about setting the preload to EXACTLY 1/2 or EXACTLY 3/4.

I don't know what you took apart and what you replaced, but I think I read that the heads were off. Did the push rods end up in their original positions and orientation? Did the lifters get removed?

Dan

[mmwjr]

Dan I'm glad you wife has trained you well at responding to pages

Thanks for you help clairifying. Also thanks for pointing out the exhaust/intake order.

[ss3964spd]

Ha! She's been training me for years, Mike, and almost has me to the point of being able to take me out in public.

Almost.

[mrxitmt]

Dan
Because the engine had only 5 hours on it,I didn't think it was so important to keep the pushrods in order. I didn't remove the lifters.Back in the day we would run the motor , loosen the nut until the valve taped and then turn it in about a half turn.Here is how i installed the rods Turn the crank til the lifter was down ,loosen the rocker bolt 4 turns drop in the push rod tighten the rocker bolt 4 turns.The specs in the book state a 10 to 27 thousenth clearance, but like I said, I've never adjusted hydrolic valves with the engine off,but I don't want any more problems , so I'll do as you all say

[ss3964spd]

Rick,

Flat tappet lifters are far more sensitive to being put back on the same cam lobe they came off of. Push rods - not so much. Still a good practice though. If your engine has roller lifters then putting them back where they came from isn't necessary. Since yours weren't removed at all, the point is moot.

Yes, back in the day I've adjusted hydro lifters with the engine running. Even with clips that cover the rocker arm oil holes hot oil still got all over the place. It's just a pain in the ass and unnecessary. You can bet that when the engine was origionally built the factory did not adjust them with the engine running.

I haven't read the Merc manual for their adjustment procedure so I don't know what exactly they mean by 10 to 27 thou clearance. The 10 to 27 must be at the rocker to valve tip and after the pre-load. 10 to 27 thou is a huge spread which tells you how much variance hydro lifters can deal with.

[mrxitmt]

Today I finished the exhaust and finally got it started ! Everything so far looks and sounds good.Tuesday I will set the timing do the valves and try her out.If all goes well with that I'm back on the water !!I'll clean her up and get ready for next summer!!!

[mmwjr]

Sounds encouraging Rick. Good luck and keep us up to date on the progress.

[mrxitmt]

Took the boat for a run armed with my infrared thermometer . all looks good except one hot spot in the center of the heads where the intake bolts on at 200.I think this may be where the exhaust passes into the intake .ran good .one question....timing is 8 BTC but the pointer does not have degree marks , just one groove .


Rick

[mmwjr]

Rick,
that's good news. Yes the center 2 cylinders exhaust port are next to each other in the center of the head. Did you get the same reading on each bank of the engine (I think you are said you did but not 100% sure)?

So only one groove on balancer and timing cover?

[mrxitmt]

so far as I can tell there is a single notch on the timing cover and one groove in the balancer . I just set the timing a little before the notch . It seems to idle ok on it or before it But I want to get everything right.

[mmwjr]

Not sure but I wonder if they took into account the BTC when making the engine and the two should just be lined up. Maybe someone with more GM knowledge knows, anybody?

[ss3964spd]

I like Mikes logic but I have no idea. Only way to know for sure is to consult the manual.

[mmwjr]

I looked in my manual and it doesn't say anything either way. I know newer engines are just set to TDC and then the computer adjusts the timing from there but no computer in this case. I guess it's time to google and see what comes up.

[pascavone]

call jasper engines, since they rebuilt the thing.