For the grip length, you can work that out by measuring the thicknesses of the parts you have.
For the material, steel is obviously stronger, but harder to install.
I don't know anything about the T-tops; I can't say if aluminium would be strong enough. However, if the aluminium gets wet, it may be corroded via galvanic corrosion.
For the grip length, you can work that out by measuring the thicknesses of the parts you have.
For the material, steel is obviously stronger, but harder to install.
I don't know anything about the T-tops; I can't say if aluminium would be strong enough. However, if the aluminium gets wet, it may be corroded via galvanic corrosion.
Well there's at least 30 main large rivets, with probably another 30 smaller or supporting rivets, it seems like 1/4" aluminum rivets are good for about 1000 pounds shear strength? So it seems they would be more than adequate. The main rivets are installed from the interior and are mostly sealed off from the elements, but there are many rivets on the outside just under the panels and trim.
So, I'm now confused about the head gaskets (I recieved my permatorque severe duty head gaskets today), I looked into it more and while many people call the permatorque SD gaskets MLS, in some documentation felpro has 3 distinct options: MLS, permatorque SD, and permatorque. The versions for the 3.1l (your engine) has normal permatorque and permatorque SD, which is fancy looking black with blue rubber seals. For the 3400 (my engine) there's permatorque and permatorque SD, which looks very very similar to the normal one, same construction, just maybe a darker color. Other engines that have the felpro MLS head gaskets are very clearly multiple loose layers held together with rivets. Were your head gaskets clearly multiple layers, or do you maybe not have MLS head gaskets? Just a fancier version of a more normal style? MLS head gaskets also don't seem to use the "fire rings" that your fancy permatorque SD and my not so fancy permatorque SD have.
From the cut edge, I was able to see that the gasket was indeed made from multiple layers of steel. The layers were not paper-thin, there were perhaps (going from memory here) 5-6 layers in total.
I just looked on Rockauto for the Permatorque SD 541SD gasket for the 3400. It looks to be dark grey without the blue areas. Maybe the "Permatorque SD" branding is applied to gaskets having a different construction (i.e. it is meaningless marketing wank).
You may also consider using head gaskets for the 3.4 F-body, since you are using the iron heads. The 3.4 F-body and Fiero gaskets look essentially the same, except for the diameter of the fire ring.
The 3400 head gasket is missing one hole at each end; I don't know if this matters or not. You should also compare the engine blocks visually (with photos if you don't have a Fiero or 3.4 F-body block available) and see which gasket makes more sense to use.
I'm running the 512SD gasket for the Fiero, which is now discontinued. If later I can only get 513SD (3.1L Gen 2) gaskets, I'll wonder whether I should run them as-is, or maybe I could punch the extra holes.
[This message has been edited by pmbrunelle (edited 05-16-2025).]
From the cut edge, I was able to see that the gasket was indeed made from multiple layers of steel. The layers were not paper-thin, there were perhaps (going from memory here) 5-6 layers in total.
I just looked on Rockauto for the Permatorque SD 541SD gasket for the 3400. It looks to be dark grey without the blue areas. Maybe the "Permatorque SD" branding is applied to gaskets having a different construction (i.e. it is meaningless marketing wank).
You may also consider using head gaskets for the 3.4 F-body, since you are using the iron heads. The 3.4 F-body and Fiero gaskets look essentially the same, except for the diameter of the fire ring.
The 3400 head gasket is missing one hole at each end; I don't know if this matters or not. You should also compare the engine blocks visually (with photos if you don't have a Fiero or 3.4 F-body block available) and see which gasket makes more sense to use.
I'm running the 512SD gasket for the Fiero, which is now discontinued. If later I can only get 513SD (3.1L Gen 2) gaskets, I'll wonder whether I should run them as-is, or maybe I could punch the extra holes.
Ok, interesting, the 541sd is dark grey, on one side, and a slightly darker version of the striped blue on the other side. That's the only difference that I can tell.
I did have the Firebird 3.4 gaskets on it, so I'll look at the block a little later today and see what's under that hole.
[This message has been edited by 1985 Fiero GT (edited 05-17-2025).]
Ok, so the Fiero 2.8 and the Camaro 3.4 and the iron heads have passages under the missing holes on the 3400 gaskets, the 3400 block also has coolant passages there (although a little offset from the 3.4 Camaro head gasket hole). The hole above the circled one does not exist on the 3400 block on the front of the engine, but does at the rear of the engine, from pictures I've found that's the same as the 2.8 and 3.4.
So I guess I made the right choice unknowingly to start with by getting the standard Camaro 3.4 head gaskets, and those are what I should use, that extra coolant hole should be used probably.
Ok, got the donor junkyard engine a while ago, and did some tear down on the blown engine yesterday.
Most of the bearings and associated journals were scored, #4 rod bearing was flattened and had spun a bit in the rod. Worst of the main bearings.
I think there was maybe approx. 1 main bearing, 1 rod bearing, and 1 cam bearing that didn't have fingernail catching gouges.
Crankshaft: The corroded part on my camshaft, all the lobes had slight rust/imperfections in a line with that, but that was the only one where that happened at the peak of the lobe, it wouldn't have lasted too long probably. Would have been a high or low spot as the engine sat at the junkyard and condensation or other things gathered there.
The "new" engine I got is a mixed bag, it had water or coolant or something muddy in one cylinder, not enough to have locked it up (piston in the middle of its motion, will move down freely, but won't go past the rust halfway up, I also haven't tried to push it). The crankshaft looks fine, journals are smooth, camshaft looks fine, no corrosion anywhere and smooth journals and lobes. I have those cleaned up and waiting to be installed. I think I'll use the blown engine's block, and 5/6 of the pistons/rods (replace the spun rod/piston with a rod/piston from the donor, I'll use the rings from the blown engine though just to keep all the rings matched to their cylinder bores). I'll also use the lifters from the donor engine, they all looked fine. I've cleaned the blown block with 4 steps, first I hosed it down (spraying water into every coolant and oil port, and everywhere else), then immediately I used half a jug of cleaner/degreaser and scrubbed everything accessable, then I hosed it down again, same method as before, then I used a whole can of brake clean focused on all the oil passages, spraying it in one hole and having it come out 5 others haha, so hopefully there shouldn't be any more metal left. Before I install the cam I'll probably reinstall the oil pump and put an oil pan and filter on and run the pump with a drill, just pumping that oil though everything and the filter should catch anything leftover by the cleaning process, as well as making sure there's oil and not brake clean or degreaser ready to lubricate the engine when it is reassembled. One major downside of reusing the block is that I'll have to replace the cam bearings (trashed), but that's easier than dealing with the rust in the cylinder on the other one.
[This message has been edited by 1985 Fiero GT (edited 05-23-2025).]
You have a fair number of pictures with what appears to be water droplets. Is this after washing the parts? Are you drying them after?
It is a bad idea to use a piston/rod assembly from one engine in another (used) engine block.
If the replacement piston/rod is slightly taller than the original one, the replacement piston ring may run into the wear ridge created by the original piston ring.
Gun barrel brushes are ideal for cleaning deep oil passages.
[This message has been edited by pmbrunelle (edited 05-24-2025).]
You have a fair number of pictures with what appears to be water droplets. Is this after washing the parts? Are you drying them after?
It is a bad idea to use a piston/rod assembly from one engine in another (used) engine block.
If the replacement piston/rod is slightly taller than the original one, the replacement piston ring may run into the wear ridge created by the original piston ring.
Gun barrel brushes are ideal for cleaning deep oil passages.
All the parts pictured are the bad parts, the scored crank, scored bearings, scored cam, those were laying nearby as I cleaned the engine, so got splattered with water, they eventually got dried, but they don't matter, the block and any good parts are getting water, then degreaser, then water, then brake clean, then drying with some paper towel.
For the piston and rod, I'll still be using the rings that were in that cylinder, all cylinders will keep their respective rings, and only the knocking and spun bearing one will get a piston and rod from the "new" engine (exact same engine/year range, same rods, same pistons). I also can't see or feel any wear ridge on the bores of any cylinders, whether that would be something that is still dangerous at measurements smaller then I can detect, I don't know.
Originally posted by 1985 Fiero GT: I also can't see or feel any wear ridge on the bores of any cylinders, whether that would be something that is still dangerous at measurements smaller then I can detect, I don't know.
If you can’t feel a ridge with your fingernail, it’s probably ok.
For bigger ridges, a ridge reamer can be used to cut off that excess metal.
Alright, I measured all gaps, installed the crankshaft and replaced a few of the pistons.
Some of the pistons had some vertical scoring on the skirt, just enough to catch a fingernail on, and had worn the slight horizontal marks down (they all had tiny horizontal circular grooves as a part of the finish, not wear)their associated bores had some vertical scratching in the lower half, but nothing that would catch a fingernail, so I replaced those pistons and the one with the spun bearing on the rod with the good pistons/rods from the donor motor. Funnily enough the spun bearing one didn't have a scored skirt, so I think I replaced 4 pistons in total, one for the bad rod, the other 3 had scored skirts, the good pistons all still had the horizontal ridged finish that could be felt with a fingernail on the skirt, the pistons with the extra wear were the ones that were rocking back and forth a "lot", the replacements and the 2 good ones still moved, but not as much.
Piston ring gaps were all more than enough (according to online calculators I only need about 0.020 or so, I measured them fairly close to the top of the cylinder, maybe that increased the size slightly): Cylinder number, top ring, second ring. 1, 0.042", 0.050" 2, 0.045", 0.054" 3, 0.042", 0.054" 4, 0.030", 0.042" 5, 0.034", 0.046" 6, 0.034", 0.046"
That's a maximum variance of 0.015" for the top ring, 0.012" for the second ring, as I've said before, all of these rings are still in their matched bores, so they all have the same mileage and should have had the same life. I also measured cylinders 2 and 4 rings in each other's cylinders to see if it was the rings or the bores that were giving the varied reading, I got the exact same measurement between the 2 bores with both sets of rings, so the rings have the variance.
Rod bearings measured: 1, 0.001", 2, 0.001", 3, 0.001", 4, 0.001", 5, 0.001", 6, slightly over 0.001", but still closer to that than 0.0015", the next step on the plastigauge. Recommended spec is 0.0007-0.0024", so I'm on the low side of that for all.
Main bearings measured (timing side to flywheel side): 1, 0.015", 2, 0.015", 3, 0.020", 4, 0.020". Recommended spec is 0.0008-0.0025", so it's still within spec, with the rear 2 being on the high half, front 2 being about in the middle.
