Does anybody do this anymore?

GPster · February 08, 2007, 09:08:12 PM

Years ago when you installed heads on an engine the head gasket manufacturers reccomended re-torquing the head bolts after the engine was run. I had that 4.3 V6 running (shortly) and I'm wondering if I should run it again, let it get warm, and re-torque the heads before I put coolant in the system and start doing any final assembley. If yes is the answer do you normally back off on the intake manifold bolts to let the heads firm up straight. My neighbor/mechanic says he usually just add 10# to the high end of the torque spec and lets it go at that. When I got this engine i could see that the head gasket was blown probably after re-assembly. I couldn't find anything wrong except maybe shody workmanship but I just would like thoughts as to whether I'm being over cautious. GPster

Leon · February 08, 2007, 10:37:27 PM

I thought the newer head gaskets didn't require retorque.

enjenjo · February 09, 2007, 12:18:11 AM

Quote from: "Leon"I thought the newer head gaskets didn't require retorque.

Most don't, but some still do. Check the instructions with the gaskets.

tomslik · February 09, 2007, 05:31:26 AM

i wonder if you realise how much work is involved(+parts) to retorque head bolts in some of these engines?
no, i don't retorque, i don't get paid to retorque.
besides, most late model light duty and cars have TTY bolts .....

GPster · February 09, 2007, 10:41:44 AM

Quote from: "enjenjo"
Quote from: "Leon"I thought the newer head gaskets didn't require retorque.
Most don't, but some still do. Check the instructions with the gaskets.

These gaskets are Fel Pro. I threw the packages and instructions away weeks ago but checking with the supplier (Auto Zone) revealed that the manufacturer doesn't suggest re-torquing on them. Maybe I'm one step closer. Now if I could just understand what up-side down means on the gas pump. Are the lines supposed to come out of the top or bottom of the pump when installed? I'm weak on tech, GPster

slocrow · February 09, 2007, 12:47:00 PM

Quote from: "GPster"Now if I could just understand what up-side down means on the gas pump. Are the lines supposed to come out of the top or bottom of the pump when installed? I'm weak on tech, GPster

Joe; This might be an example of what upside down, referrers too.........Frank

GPster · February 09, 2007, 03:09:48 PM

Quote from: "slocrow"Joe; This might be an example of what upside down, referrers too.........Frank

That's what I thought . The way I look at the pushrod and the mechanism on the pump that's the way it should be to operate, My problem is the proximity of the fuel lines to the exhaust manifold. This style of engine originated in '78 with the 3.3, the 3.8 in '82 and the 4.3 in '85 and then quit using a block mounted fuel pump. I haven't been able to find an exhaust manifold that is an early model for sure and I don't even know what one might look like. It's easier for me to think I'm doing something wrong than to think it was wrong before I got there. GPster

tomslik · February 09, 2007, 07:26:55 PM

gpster, if ya find a pic or a casting#, give me a holler, i may have one

Hooley · February 12, 2007, 09:29:16 PM

Well every one has their own thoughts about retorquing heads. I run the engine in, let it cool. Some time for a couple of days or more and then retorque. I often find one or two a little loose. It looks like it couldn't hurt any thing even if they were tight. Just what i do.

Hooley

GPster · February 12, 2007, 10:01:53 PM

Quote from: "Hooley"Well every one has their own thoughts about retorquing heads. I run the engine in, let it cool. Some time for a couple of days or more and then retorque. I often find one or two a little loose. It looks like it couldn't hurt any thing even if they were tight. Hooley

Maybe that's tomorrows' project . Ran the engine today with water in the radiator (no pressure cap though) and a water temp gauge and an oil pressure gauge on it. 50# oil pressure at idle and no bubbles in the water. Transmission was in gear and the rear wheels were up in the air turning. Still trouble figuring out what to do with exhaust but I've got an idea but it will take a forum of it's own. I may not go as far as the back-up engine option. GPster

slocrow · February 13, 2007, 02:23:10 PM

Quote from: "Hooley"I often find one or two a little loose. It looks like it couldn't hurt any thing even if they were tight. Hooley

I agree...........

GPster · February 16, 2007, 05:37:11 PM

Isn't it strange that when you ask for advise you tend to believe the ones that say what you thought in the first place. I would have kicked myself in the --- if I had neglected putting a little more work to this so today I checked the torque. I drained the water out of the block, pulled the exhaust manifolds off and backed off the bolts on the intake. By the advise of my neighbor I had gone 10# more on the head bolt torque so I had initially torqued them to 85#. I checked the driver's side first in the reccommended rotation and the where right on. Then I went to the passenger side (that was the side that had the blown gasket) and some of those bolts had backed off. Some down to 60#. So they are back up to 85# now and the intake is tight and water is back in the block. Still haven't figured out the exhaust manifold/ fuel pump delema though. GPster

Dave · February 16, 2007, 05:45:33 PM

Interesting Joe.. Ive never backed off the intake bolts before re torquing the cylinder heads. My dad taught me how to do it years ago and he never loosened em either. Ive never had a problem and never blown a gasket. I had a jet boat with a 550hp big block chevy 121/2 to 1 compression and no problem there and i had that one apart a bunch for other stuff.
Dave

UGLY OLDS · February 16, 2007, 05:57:49 PM

I agree with Tomslik on the TTY bolt thing but that engine should not use them...Maybe check them again in a week or so?? If the same bolts are coming loose or loosing torque, they may be streching under load & ready for replacement...I see more & more SBC engines doing that...After all, headbolts can only re "re-used" so many times....Just a thought....