Projects - Engine Rebuilding Page 2

- Engine Rebuilding Project (Cont'd Page 2) -

January 3, 2003

Thanks to Aron, my heads are back and ready for action! Yeah, I know - snapped the shot before recoating them with WD-40. Oh well. Have to keep tabs on these things to prevent surface rust on the bare metal. Iron likes to rust, especially in humid-ville.

The springs have been upgraded to the Comp Cams springs. The trick with these are - you really don't want too hard of a spring on a set up that doesn't require it. It would cause unnecessary strain on the lifters, pushrods and rocker arms and possibly damaging them as well as the cam. With stock seat pressure being about 80 to 90 pounds, these at 130 - we should be good to go.

The studs have been replaced with AFR screw in studs 3/8".

Valves are the same, stock valves with a 3 angle job, bowls were smoothed as well as the intake and exhaust ports. And the heads are milled to give me about 62cc versus 64cc for a little more compression.

Nice shot of the exhaust ports.

He also blasted the intake plenum and manifold as well. Ready for paint. Pretty aren't they?

Time For Some Catching Up

A LOT has happened .. I can't believe it's been almost two years since I last updated. Well, shortly after the last update, we traveled up to PA to visit my parents who were selling their house to go full-time traveling. We were to pick up some freebies and tow back a U-Haul trailer full of goodies. Half way up, our van's head gasket decided to blow, but making it there anyway. This van was in the shop more than out since we bought it. I was a 1997 Pontiac Montana. The worst vehicle I've ever owned. And it figures, it would break down again 1200 miles away. So we had it. Traded it in for a Dodge Ram pickup. More capable of towing the trailer home and I gotta tell ya, I like it much more than the van.

So we got back and unloaded everything into our already crammed house. We were to move to our new house in October 2003. As always, buying a house is full of surprises. Once thing after the other. We eventually moved in late October. So from there went about 3 months of nothing but moving and straightening things up and fixing the house up the way we wanted it. That takes a bit of time, really. Anyway, on with the show ...

Anybody remember Page 2? I nicked the rod journal? Well ... this happened shortly thereafter ... it was standing up in my garage, in the corner, where nothing could ever happen to it. Well, a piece of hose on a shelf behind it, fell, just enough to knock it over and straight into the transmission that was sitting on the shelf next to it. The part that stuck out had the mounting bracket on it. Needless to say, it got nicked pretty bad that time, so I had to send it off to get ground. A .010 rod journal grind took care of it.

Between the last update and us moving to the new house, I managed to get the block cleaned, checked, honed and new cam bearings and freeze plugs installed. They also cleaned, shot-peened and magnafluxed the rods. I managed to paint the block and heads also. That was pretty much it until after the dust settled after moving into the new house.

Here and there up until now, I did some work on the car itself like take off the fenders, ground effects, front and rear bumper covers and rear hatch. Plus a few other things. I thought that I should do this in the mean time to clean up underneath and clean up the engine bay in preparation for the new engine. Just being hopeful I guess. I planned on rebuilding the suspension as well as treat the under carriage for what little rust is there. The reason I decided to rebuild the suspension was because I have rust forming on the strut tower caps. So, since I'm doing that .........

Anyway, back to the engine again. I finally have the full, Holley Stealth Ram set with fuel rails and adjustable fuel pressure regulator. I plan on using the stock 22lb/hr injectors at first. Those can be swapped out later. I figured a 2400 stall converter, transmission parts and internal engine parts were more of an immediate concern. I also bought a set of Comp Cams Magnum roller rocker arms at 1.52, self-align and the Comp Cams Xtreme Energy Computer Controlled XR269HR Cam, 08-502-8. It's a .495/.503, 218/224 @ 112 LSA. I was going to opt for the XR276HR, but felt that may be a little more than I wanted. In the cam world, whatever you think *may* be too much, get the next lower. Too big of a cam is worse than a cam not big enough. I'm happy with the decision. Besides, the springs, that were installed, could bind with a .510 lift cam anyway. .503 is safely below that threshold.

I also have new pistons, rings and the entire rotating assembly balanced. Shop said it wasn't bad, about 7 to 8 grams. They got down to within 1. They did tell me my flexplate was shot so that's on my shopping list of immediates along with some subframe connectors and headers.

January 5, 2005

Since I have everything I need to assemble the engine, I thought I would go ahead and do a clean up and start putting this bad boy together. I started on December 13, 2004, right around the time we had a family emergency. So back in the garage it went - one thing, forgot to lube the crank down again. So by the time I got to it again a couple of days ago, there was surface rust (or what looked like it anyway) on the crank journals. A couple of phone calls for some advice, I proceeded to repolish the crank myself. Turns out, it's not a hard job to do at all, as long as you take your time and pay attention.

The rod journal to the left is done and the one to the right is not.

When polishing the crank shaft, get the highest grit emery cloth you can find. I used 600 grit which people will still argue is too course. Have you felt 600 grit? Regardless, I've heard of shops using 320 grit. But not any lower! Since you do not apply but the slightest pressure to the journals at any given time, your attempt is to basically smooth out the journal for any corrective imperfections (i.e. surface rust and small nicks). I held the cloth around the journal, loosely, followed it around as I manually turned the crank very slowly. This was ensure I was giving it the same pressure on the full rotation. Several rotations is all that's necessary. If you still feel imperfections, you may have to take it to the machine shop for further analysis. How did I rotate the crankshaft? I installed the lower main bearings, lubed them up with engine assembly lube and placed in the crankshaft. I turned it by installing the balancer bolt and turned with the 3/8 ratchet and socket. Easy enough.

If you have had corrective surface rust on your crankshaft journals, it's normal to see, what looks to be rust still, but if it's smooth (check with your fingernail), chances are, it's stained metal (discolored from the rust). Nothing to worry about.

Time For A Preassembly Bath

Using regular dish soap and water, I thoroughly washed the block and spray rinsed. I used an air nozzle to blow dry the entire block. I coated the cylinder walls with oil immediately after drying. Also coated the lifter cylinders as well as the distributor hole. Flipping the engine block reveled the camshaft bearings. Ensuring they were dry, I applied assembly lube to each one.

We need tools ... one of the most important tools we'll find is a little cheap, dispensable tool called, "Plastigage" along with a service manual with rod and main bearing oil clearance specifications, as well as torque specifications.

Here's their directions from the Plastigage site:

Remove the bearing cap and wipe the oil from the bearing insert and crankshaft journal.
Tear off a piece of Plastigage as long as the full bearing width. (Tear through both the envelope and plastic thread at the same time.) Lay the piece of Plastigage across the full width of the lower bearing shell about 1/4" off center.
Install and tighten the bearing cap to the proper torque specifications. Do not rotate the crankshaft while making this check.
Remove the bearing cap. The flattened Plastigage will adhere to either the bearing shell or the crankshaft.
Compare the width of the flattened Plastigage at the WIDEST point with the graduations on the piece of envelope torn off in Step 2. The number within the graduations, which matches the flattened Plastigage width, indicates the total bearing clearance in thousandths of an inch or in millimeters. If the width of the flattened Plastigage does not exactly match one of the envelope graduations, interpolation can be used to determine the fraction of a thousandth in the same manner as when using micrometers.

Okay, so I cut mine with scissors ... same difference ... I used the green Plastigage rated for 0.001 to 0.003. Our tolerances are pretty tight.

Main oil bearing clearance specifications for my 1988 350 are:

Crank Journal #1: 0.0008 - 0.0020"
Crank Journals #2, #3, #4: 0.0011 - 0.0023"
Crank Journal #5: 0.0017 - 0.0032"

Estimated measurements from my Plastigage results:

Crank Journal #1: ~0.0010"
Crank Journals #2, #3, #4: ~0.0015" (all were the same)
Crank Journal #5: ~0.0020"

Although not exact, they definitely did not exceed the maximum margin, closer to the lower end. Seems right. The main journals were never reground, just polished as they didn't need it. The rod journal oil clearances will be my main concern since they were ground 0.010 due to aforementioned mishaps. Remember, don't coat the main caps with lube to check for clearances, but when you install them permanently, do. Never coat the outer bearing before installing. Just insure the back of the bearing is clean as well as the main bearing journal on the block and end caps.

Here, we have the crank checked, Plastigage removed and retorqued to manufacture's specifications which are; Inner 70-85 ft/lbs., Outer 60-75 ft.lbs. Outer meaning #1 and #5 (front and rear) and inner meaning #2, #3 and #4 caps. Since my oil clearances were pretty good at "midrange" when I measured them, I torqued the inner caps to 77 ft/lbs., and the outer caps to 67 ft/lbs.

Next step is to prep and install the pistons and rods. The machine shop had already installed the new pistons to the rods when they balanced the rotating assembly. But since I let them sit for a while, the rod ends had some surface rust I needed to take care of.

With the 600 grit emery cloth, I was able to remedy that problem with little effort.

I also wiped down the rod ends (including the rod caps) with a rag damped with automatic transmission fluid. Apparently, that works great in cleaning up this type of stuff, along with the cylinders too! Keep wiping with clean paper towels until it comes out white. Trust me ... there was no dirt in those puppies. Amazing the little tricks you learn.

Here I'm ready to install the piston rings from Speed Pro. Read the instruction kit to install the rings. There are tools that spread the rings out to install, but I prefer the "roll-on" method. Unfortunately, on my last piston (as they're numbered), I broke the second compression ring by stressing it too hard. Not hard to do, just have to be careful. Luckily, Summit Racing was gracious enough to send me a new one free of charge! So I'm still waiting for that part. One key note: Some ring kits will have plastic end protectors on each end of the oil control rings. They protect the rings from damage during shipment, but should be removed before installing!

In the mean time, I took each compression ring and placed them in their corresponding cylinders (I've already decided which set will go on which piston), using the piston as a press, push the ring down in the cylinder. Measure the gap between the ends with a feeler gauge. It should be no wider than 0.020". All of mine were pretty much right between 0.010 and 0.020 as in spec.

When installing pistons, you will NEED a piston installer, piston ring compressor, whatever they want to call it. Essentially, you place the piston with it opened up, and you tighten it up to where the piston will slide down it into the cylinder of the block.

Ensure you lube the cylinder with gracious amounts of oil. Ensure your piston and rings are clean of all debris and dirt (air compressor is good for this). Also ensure your piston installer tool is clean. Place the piston in the installer, adjustment up top, and tighten. You don't want to tighten it too much to where the piston won't move, but you don't want it to be too loose to where the oil control ring retainers bind as you're tapping in the piston. Install some 5/8" rubber tubing on the rod bolt threads to prevent damage to the journals. Coat the rod bearing with engine assembly lube.

Tap the top of the piston with the butt-end of a hammer, rubber mallet, anything that will not harm the piston. Never use anything metal or hard to tap the piston into place. Once the piston is on, ensure to guide the rod end on the rod journal on the crankshaft. It's a lot easier to have the crank rod journal directly below the cylinder, at its lowest position.

Cut your Plastigage to the width of the rod end, not the entire rod journal. Install the rod cap with NO lube, same as the main bearings, measure your oil clearance, torquing your rod caps to 45 ft/lbs (as specified). The rod journal oil clearance specification for this engine is 0.0018 - 0.0039. My clearances measured pretty close to 0.0020, well below the 0.0039 maximum recommended specification on ALL rod journals. Some will argue that because the tolerances are so tight, they you'll enduce more friction. Perhaps. But I find it better as I have more room for wear. Just ensure I use the recommended oil weight of 5W-30 at the most (as I always did)

When you're done measuring the clearances, remove the caps, remove the plastigage (they dissolve in oil), lube the rod end caps and torqe everything back down, take a look at each cylinder when you're done. Ensure the pistons are centered in each cylinder. If they seem to be off to one side more than the other, something didn't seat right. Remove the piston, check for dirt, clean up and try again.

TIP: When installing any caps .. rod or main, do it in 10-20 ft/lbs. increments to ensure even installment.

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