Overhaul the heads or go with a long block?

[Joshua Nichols]

Well after last time out the 4.3 in my boat started running weird.. Not a major drop in power but I noticed it.. Had a weird noise too..

Did a compression check.. The highest was 150 and the lowest was 130.. So I busted out the leak down just to see what is going on.. Took the valve cover and exhaust manifold off.. Found that I have a couple of burnt exhaust valves(Bubbles up some windex real good).. This is just on one side.. Haven't ran the leak-down on the other side yet.. Still afraid we will have similar issues over on that side too.. Will likely be beyond a lapping compound fix.. IDK

I am guessing that this engine is about 8 years old.. The PO told me he replaced it once about 7 years ago.. Coulda been 10 years ago for all I know.. I know he ran the tar out of it..

Here is the question.. Should I have the heads redone? Don't even know where a good shop is around here.. Also back when I use to get heads done.. The shop sprung for the bill and I don't remember how much it cost..
Or should I just bite the bullet.. Get a rapido longblock and replace a possible tired engine... Not real trilled about dumping $1450 bucks in a boat that I only paid a grand for.. Yet it does have brand new manifolds on it..

Sometimes I really miss my little Yamaha outboard...:facepalm:

I know.. The poll is pointless.. Still I like em and appreciate your vote

 

[RogersJetboat454]

Re: Overhaul the heads or go with a long block?

As long as your oil pressure looks good, and the noise you hear isn't in the bottom end, I see no reason why you shouldn't get the heads done. You may want to look around for deals on Ebay too. Seems like lots of machine shops will referb popular heads to sell on ebay.

 

[RIDEPATE]

Re: Overhaul the heads or go with a long block?

I'd agree Josh. If the oil-pressure was good and the bottom-end was not noisey, freshen-up the top and boat-on. If the bottom does give-up then you've got a good set of heads for a short-block.

 

[Joshua Nichols]

Re: Overhaul the heads or go with a long block?

Well I have pretty good oil pressure.. 40psi ish.. It drops after a bunch of hard running.. Was told on this very forum that it isn't that uncommon.. No noticed bottom end noise...

Now this is something I noticed.. I could hear one of the lifters bleeding down.. Not sure if that is common or what.. A little snap once every minute or so.. Change the lifters while the top end is off?

Well since I don't have $1400 laying around to throw at the boat.. Going to have the head work done.. I lucked out and one of my ol mechanic friends has a shop and knew where to send the heads(they pick em up and drop em off) and will let me use his account.. Helps to still have friends in the industry..

I ran around today and couldn't find a descent machine shop in my area.. Looks like the economy has taking it's toll on them.. Found some closed ones

I wish I had the cash to long block.. I have to do a engine pull to replace all the motor mounts, and woulda been nice to have a fresh engine to install at that time.. Oh well.. Like I say.. Hope and boat don't work together and wishing is just dreaming..

I will follow up post all the fun..

Any felt or needed advice is appreciated

Do I need to purchase a new head bolt set for this sucka? Are they torque to yield bolts? I am not a GM guru by any means

 

[RIDEPATE]

Re: Overhaul the heads or go with a long block?

I have no clue about the head-bolts...sorry.

 

[Joshua Nichols]

Re: Overhaul the heads or go with a long block?

I have no clue about the head-bolts...sorry.

You would think someone would know...

 

[donberry]

Re: Overhaul the heads or go with a long block?

as long as they are the same as in a car, no, you do not need new head bolts and I don't see why they would be any different.
I rebuilt some heads once and to save a whole bunch of money, bought myself a Haynes manual for rebuilding that engine, tore the heads down myself and then took them to the shop to clean them up for me (they just have a giant "degreaser" that makes them look like new)
Brought them home and rebuilt them myself. I had never done anything like that before and it turns out it is not really that hard - I just went to autozone when needed to borrow specific tools for the tasks (valve pullers etc).
By doing it myself I ended up being able to afford new parts for it, spings etc.
Still running like a top years later. It really is not that hard as the manuals pretty much walk you right through it.
I mainly did it because I always wondered how an engine really worked. Saving a bunch of money was just icing on the cake

 

[Joshua Nichols]

Re: Overhaul the heads or go with a long block?

as long as they are the same as in a car, no, you do not need new head bolts and I don't see why they would be any different.
I rebuilt some heads once and to save a whole bunch of money, bought myself a Haynes manual for rebuilding that engine, tore the heads down myself and then took them to the shop to clean them up for me (they just have a giant "degreaser" that makes them look like new)
Brought them home and rebuilt them myself. I had never done anything like that before and it turns out it is not really that hard - I just went to autozone when needed to borrow specific tools for the tasks (valve pullers etc).
By doing it myself I ended up being able to afford new parts for it, spings etc.
Still running like a top years later. It really is not that hard as the manuals pretty much walk you right through it.
I mainly did it because I always wondered how an engine really worked. Saving a bunch of money was just icing on the cake

Yeah I guess I could do all that mess.. Have lapped a ton of valves..

Still pretty easy to take it to the shop.. It has burnt valves in it now.. Head work is a PITA.. Springs flying, and lost valvestem clips.. Yeah I been there.. I have a ton of other work to do on this thing now.. I think I will have the head work done buy a a good recommended machine shop..

Even after 10 years of being a diesel mechanic..
I hate head work..
Hate the smell of 90wt gear lube and I hate AUTOZONE..
NAPA rules.. Well only if ya bring your own part numbers

So how much did ya save? Do you have a lathe in your garage? If so.. Super cool

 

[Joshua Nichols]

Re: Overhaul the heads or go with a long block?

I thought some of the GM stuff uses those torque to yield bolts.. I guess my manual would have it listed

 

[HT32BSX115]

Re: Overhaul the heads or go with a long block?

Do I need to purchase a new head bolt set for this sucka? Are they torque to yield bolts? I am not a GM guru by any means

I'll bet the Mercruiser service manual would probably indicate if new head bolts are needed.

Stretch bolts are frequently a diesel or aluminum head thing........If you want to REALLY be trick, get yourself a set of ARP studs....

 

[Joshua Nichols]

Re: Overhaul the heads or go with a long block?

If you want to REALLY be trick, get yourself a set of ARP studs....

Still

Would make gasket lining up easy wouldn't it...

 

[HT32BSX115]

Re: Overhaul the heads or go with a long block?

Studs just make it easier all the way around!

 

[Lou C]

Re: Overhaul the heads or go with a long block?

I've got the factory OMC shop manual, in the V-6/V-8 section, it does not say anything about replacing the head bolts, all it says is to clean and lubricate the head bolts with OMC gasket sealing compound......

Speaking of bolts vs studs and nuts, I just changed the manifolds on my 88 4.3...the studs OMC used made it an easy job, spray a little PB on the stud/nut and they came right off, slide down the exhaust hoses on the Y pipe and they were off in a few minutes. Those studs and nuts were plated with something because there was not a bit of rust on them either....

Back to the original question, it's hard to say, I have heard that doing a valve job on an old engine brings back compression that the old rings can't hold, not sure if thats true. It depends on how long you want to keep that boat, if a long time the long block makes the most sense, but if a few years, you could roll the dice and do the heads.....
Here in the salt pond, no one takes apart raw water cooled engines so you'd most likely have to do a long block....

 

[rickryder]

Re: Overhaul the heads or go with a long block?

I could hear one of the lifters bleeding down.. Not sure if that is common or what.. A little snap once every minute or so.. Change the lifters while the top end is off?

If you change the lifters you'll want to do the cam too..... and cam bearings....

 

[Joshua Nichols]

Re: Overhaul the heads or go with a long block?

damnit

 

[scooper77515]

Re: Overhaul the heads or go with a long block?

Josh, I have all the tools needed to do a head job. Get them off, have them hot-tanked, and bring them over. I could work on one while you work on the other, have em both done in a couple hours.

Pick up a set of new valve-stem seals. Have the heads done for cheap. My last hot-tank was $100 per pair.

 

[Joshua Nichols]

Re: Overhaul the heads or go with a long block?

Josh, I have all the tools needed to do a head job. Get them off, have them hot-tanked, and bring them over. I could work on one while you work on the other, have em both done in a couple hours.

Pick up a set of new valve-stem seals. Have the heads done for cheap. My last hot-tank was $100 per pair.

Well I have to get up the drive to tear them off.. I been consumed by playing with the new hot rod..
Can't work on it except at night...

 

[scooper77515]

Re: Overhaul the heads or go with a long block?

Too damned hot, anyway. And no lake to use it in, until we get some serious rain.

 

[Joshua Nichols]

Re: Overhaul the heads or go with a long block?

Too damned hot, anyway. And no lake to use it in, until we get some serious rain.

Yeah you know the minute i got it up and running i would have to be on the water so I could test...