Oh I agree! They will do what a truck needs.Originally Posted by 1project2many
But still can't shake the 16 MPG highway with the Vortec but can hit 18+ with a TBI? I've only read that a 0411 swap with lean cruise will do 21... we'll see soon.
Oh I agree! They will do what a truck needs.
But still can't shake the 16 MPG highway with the Vortec but can hit 18+ with a TBI? I've only read that a 0411 swap with lean cruise will do 21... we'll see soon.
1990 Chevy Suburban 5.7L Auto ECM 1227747 $42!
1998 Chevy Silverado 5.7L Vortec 0411 Swap to RoadRunner!
-= =-
Well... after another week of crazy late nights and a marathon session at the shop yesterday I got to hear the 302 run. For about 10 seconds. Turns out I've got something wrong inside the engine. I've built quite a few engines over the years and except for the first one I ever tried to build back when I cashed my paychecks at the liquor store I've never had a major problem. But this thing's turning pushrods into modern art in just two or three crank revolutions. My guess right now is that either the pistons were installed on the rods incorrectly and I didn't catch it, or they were installed correctly but I flipped the rods 180 degrees. Either scenario would put the valve reliefs on the wrong half of the piston. Very frustrating. I just ordered a cheapie reman crankshaft for the 5.7 that came out and I'll be putting in more late nights putting that back together and back into the 'burb so we can use it for Christmas. Then I'll dig back into that 302 and see what the $%^ I messed up.
Last edited by 1project2many; 12-18-2012 at 12:27 AM.
Well that sucks! Especailly when you know better. I went through a bunch of pushrods with a big cam on my first motor build in high school. Didn't know anything about releifs back then...
1990 Chevy Suburban 5.7L Auto ECM 1227747 $42!
1998 Chevy Silverado 5.7L Vortec 0411 Swap to RoadRunner!
-= =-
Well, I have a similar not good engine rebuild experience to share. See pics below.SBC 406, 6.0" rods.
dave w
Dang dave, what happened to that thing?
79 Jeep Cherokee, AMC 401, T-18 manual trans, hydroboost, 16197427 MPFI system---the toy
93 Jeep YJ Wrangler, 4.0L, 5 speed, 8.8 rear, homebrew hub conversion and big brakes, hydroboost, 2.5in OME lift, 31x10.50's---the daily driver
99 Jeep WJ Grand Cherokee limited, 4.0L, auto, 2wd, leather and power everything, 99% stock---the long distance highway ride.
Thanks for sharing. 406 parts aren't cheap especially with those long rods.
What's the pink stuff?? Obviously something hard enough to do damage. Piece of a bolt or screw that got sucked in?? Is that groove too deep to run?
The engine was fresh from the machine shop, which also assembled the engine. It appears to me, something foreign was in the ring compressor when the piston was installed into the engine. I'm requesting the machine shop sleeve the damage cylinder, at their expense.The machine shop insists the cylinder only needs a hone. Drama, Drama, Drama, I can't say I want to do business with a machine shop that is reluctant to fix the problem the way I think the problem should be fixed.
Anyway the first picture shows how the piston valve reliefs should be installed.
I'm not sure what the pink stuff is, paint from the rings or maybe assembly lube?
dave w
Last edited by dave w; 12-19-2012 at 05:32 AM.
Dave... Are you saying it's part of a ring compressor?? For 4" bore engines I have a nice, adjustable tapered aluminum compressor that I use. I'll be using it tomorrow if all goes well.
Pulled heads and pan but left the block in the truck. Pistons are installed backward. Rods, however, are installed correctly. So the machine shop assembled pistons to rods incorrectly but I'm still a bonehead for assembling it this way. I built the engine between the time I injured my back and the time I had surgery and all I can figure is the pain killers I was taking had something to do with it. It's no excuse but I can't see any other way I'd let something so obvious go. So tomorrow am I arrive at work early and knock the pistons out. During the day I'll either send the rods/pistons to another shop or try my hand at disassembly / reassembly using a torch to loosen the pressed pins. Hopefully the local GM dealer will have the head gaskets I used in stock so I don't have to wait for those. Part no 10105117 .028" compressed thickness.
Now I have a 45 minute drive ahead of me to get home so I can catch a few hours sleep and be back up at 4:30 to head back to the shop.
List of things to bring in from home tomorrow:
Tapered Ring Compressor,
Coppercoat
Toaster oven for heating rods
Patience, patience, patience.
I'm thinking some debris was on the ring compressor. Who knows where the debris came from, maybe the debris was in a shop towel that was used to wipe the ring compressor? Maybe the debris was on the shop table where the ring compressor was set down between pistons? I don't think the debris is from the ring compressor, most likely the ring compressor picked up the debris from somewhere just before compressing the rings?
dave w
That story just sucks...How long has that motor been sitting waiting for a home? What a bummer...
How exactly does a machine shop press these in? They don't use heat do they? Torch on new pistons and rods scares me... Or do you not have a press?
I hate to say this but are the valves OK? Back in 1977... yup I'm old... I bent 2 sets of pushrods and didn't hurt a valve. I even pulled timing chain cover to see if I had it wrong, before I realized I built it wrong .
Man I'm sorry, that is a bummer. Like you said PATIENCE!!! Sounds like your tired to boot... patience...
1990 Chevy Suburban 5.7L Auto ECM 1227747 $42!
1998 Chevy Silverado 5.7L Vortec 0411 Swap to RoadRunner!
-= =-
All the ones I have seen, have either a gas fired or electric heater that heats the small end of the rod enough to ease the insertion of the pin. AFAIK, they still press them in as they are quite a tight fit. I can understand why they are such a tight fit too, last thing I would want is to have a pin walk out once the engine got up to temp.
79 Jeep Cherokee, AMC 401, T-18 manual trans, hydroboost, 16197427 MPFI system---the toy
93 Jeep YJ Wrangler, 4.0L, 5 speed, 8.8 rear, homebrew hub conversion and big brakes, hydroboost, 2.5in OME lift, 31x10.50's---the daily driver
99 Jeep WJ Grand Cherokee limited, 4.0L, auto, 2wd, leather and power everything, 99% stock---the long distance highway ride.
I can see heating the rod before pressing it in. And even freezing the pin for ease of install. But taking them apart to reuse parts? That's touchy... I've done a lot of carrier bearings on my press and have watched it bow before the bearing starts to slide on. Doing this with a piston I want to reuse would raise my blood pressure! I'd have to make some kind of jig to hold piston. Never actually watched it done at machine shop...
1990 Chevy Suburban 5.7L Auto ECM 1227747 $42!
1998 Chevy Silverado 5.7L Vortec 0411 Swap to RoadRunner!
-= =-
When working in a GM dealer in the late 70s early 80s , one of the required special "J" tools was a fixture made to press out wrist pins. We did use it and had good luck but it sure isn't the best way to install wrist pins. Using the electric heaters the machine shops have is the best answer.
Actually pressing pins out can be tricky. As mentioned, proper support for the piston is critical and it's not unheard of to do damage during the process. It's not a job I like to do if I don't have to.
Judicious application of heat to the small end of the rod and quick action after heat is applied works to get the pins out without a press. The trick is to apply the heat quickly but not in so small an area that damage is done. It's best if the rod is heated without discoloring but most of the time it turns some shade of blue despite best efforts. That's just the way it is.
Luckily I didn't have to worry about that because I was incorrect... the pistons are oriented properly. I thought they were wrong last night (yes, I was very, very tired when I posted) but for some reason I decided to check another engine I have this morning and realized I'd made a mistake. At this point I'm kind of stumped. All I can figure is the valve springs are too stiff and the pushrods are collapsing. I've checked everything I can think of to check including the lift on the cam in case GM sent the wrong one. I don't see any collision marks on the valves or pistons. The valves aren't bent and they're sealing well. The guides have been machined for more lift than stock and there's no sign the spring retainers made contact with the seal. The pushrod holes in the head have been opened up for the 1.6 rockers and anyway the problem is there with stock rockers. The springs appear good for over .540" lift and the max this cam generates is .480", which is small. I have no way to test spring pressure so I'm out of luck there but I believe they are K-motion K-750 springs which are a fair amount higher pressure than the LT4 spring that GM uses on most crate engines. I'm going to replace the springs with stock L31 springs, install a couple more pushrods, and try it again. Not sure where to go if this doesn't work. This is a near stock, mild build and I shouldn't have issues like this.
Last edited by 1project2many; 12-20-2012 at 01:07 AM.
I have heard of valve spring bind but sounds like you checked that.
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