Teardown started on the 352 last Saturday morning. I didn't have an engine stand freed up, so I completely tore it down while it was sitting on an engine cradle. I'm expecting a medal based on my bravery and my ability to lay on the floor, brace my foot up against the bellhousing flange and use a breaker bar to loosen the rod/main bolts. Well, it was either bravery or stupidity. Maybe a little of both. On second thought, it was pretty much all stupidity.
I couldn't be more happier with how the 352 performed or how reliable it was. Between the first dyno iteration (not counting when we dyno'd it in stock 2V form) and the last iteration, we picked up almost 100 horsepower, going from 433 hp to 531. I checked the oil filter after each dyno session and each time I was rewarded with a completely clean filter media.
What I ended up in final form was a 352 with factory heads and 10.25:1 compression that ended up making 531 at 7200 rpm with 457 lb-ft of torque. At .040" overbore, it made for 359 cubic inches, which ended up making 1.48 hp/ci. I'm pleased. FWIW, as a comparison, my bracket race 347's for 7/7.50 index will usually make about 540 hp with AFR heads, 11:1 compression, etc. Now, to be fair, they will do it with a lot less camshaft than the 352 had, but there's a testament to how well a factory headed combination can behave.
I was also happy to be able to do so many dyno sessions close together. I'm not happy as to why I had that much spare time though, because there are a lot of parts manufacturers that really have the motorsports industry in a real bind right now. Pistons are taking 12-16 weeks. Heads are non-existent. Intakes are non-existent. Lifters are non-existent. How we are supposed to get engines out the door is something that no one has an answer to right now. But I digress....
If you remember, I first started the build with my non-adjustable roller tip rockers. This was an exercise in patience and critical measuring, as trying to nail lash with nothing but pushrod length, lash caps, and lash cam shims, almost whipped my hindend. It wasn't really a desire to make a non-adjustable roller rocker work with a solid cam, but it was a desire to *really* test the rocker setup out since the valve springs were set up at 680 lbs open. The rockers made it through like a champ and then since I had the heads ported and the valve job changed, I switched over to T&D street rockers.
I have always ran T&D streets at around 600 lbs of spring pressure and then upgraded from there. However, this time, I wanted to try a new locating method to keep down some of the sloppiness associated with a stand hole that's bigger than the stand stud and the resulting rocker stand fretting. The heads were setup with TimeSerts in the stand holes and then the bottoms of the rocker stands were counterbored so that we could fit bronze bushings inside. The bushings were reamed to fit the stand studs and this locked in the entire rocker assembly. Fretting disappeared and lash stayed constant. I will use this option for future Tunnel Port head setups as converting those to T&D paired rockers can be excruciating.
IMO, both of those points were fitting for a "dyno mule" and I'm pleased with the results.
I was mainly interested to get down to the pistons and bearings. I didn't expect much considering how clean the tops of the cylinder heads were and how clean the filter was, but it's always interesting to see what's been going on.
When the heads came off the first thing I noticed was that all 8 pistons had been giving the heads a slight smooch on the quench pads. I purposefully built the engine with a tight quench, with the pistons being .005" above deck and using a 1020 head gasket. That's a .036" piston/head clearance and even though the piston was so tall (1.920" compression height) and the piston/cylinder clearance was set at about .0035", the piston obviously still rocked considerably. Considerably enough that there was a nice ring around the top of each piston where the carbon had been knocked off. Piston #4 apparently liked the head a little more than the others, as it apparently had been tongue kissing the head instead of smooching.
I pulled the timing cover and dropped the oil pan. That's a fun little task with the engine sitting on the cradle, but once the pan is sitting on the floor, I was able to unbolt the pickup and slide everything forward. The timing chain didn't lose any tension and once the entire timing set was removed, the cam thrust plate was inspected and showed no signs of anything being amiss. The camshaft came out and a first look at the cam bearings showed a clean bill of health there as well. FWIW, I do not "clock" the cam bearings, but just line up the holes in the bearings with the oil feed hole in the mains. With 680 lbs of spring pressure and a regular old F-33 bearing, everything looked absolutely great. I think a lot of guys don't actually check cam bearing clearance, so they don't know when something is actually tight. Even though a cam bearing is more forgiving, a tight cam bearing clearance will wear just like a tight main or rod bearing.
A quick rotating torque check on the short block showed a very smooth 7 lb-ft result and then I started pulling rod bearing caps and pushing the piston/rod assemblies out.
When I had listed each dyno iteration on the dyno results page of this forum, I had listed that the rod bearings were coated. That was an error on my part, as the rod bearings were not coated, but were just plain-Jane Federal Mogul "non-race" rod bearings. Rod bearing clearances were setup at .003", as is my SOP with factory FE rod journal diameters. The bearings looked great and if it weren't for the fact that I need doweled bearings (more on that later) I would just coat them and reuse them. Keep in mind that there were no "oiling mods" done to this engine except for the oil pump mounting flange hole being blended in. Nothing was drilled out or opened up. All gallery plugs were converted to pipe thread and since the drain holes in the lifter valley were plugged, the drains to the rear and front of the valley were opened up.
Piston skirts looked great and the pistons were removed from the rods so that I could ship the rods up to Nightmist66 after he bought them.
Removing the crank was also fun. I pulled all the middle main bearing caps (bearings looked fabulous, will reuse them), then put a box under the crank and then slowly dropped the front and rear caps. Once the crank was sitting on the box, I used an engine hoist and picked everything up off the crank.
Ok, so for future plans....
I dropped the block off yesterday to be baked/tumbled/blasted and will take the block down to bare bones again. New pistons are coming in from my boys at Racetec in a 4.060" bore to fit the new aluminum rods, so the block will be bored/honed and the other machined surfaces will be touched up. We will be going to a satin black scheme instead of a '66 Ford Blue scheme next time, so the guys saying that a solid lifter FE should be black will leave me alone.
The crank won't need anything except rebalancing with the new rods/pistons.
The rods are brand new aluminum rods from R&R and I had them drill some FE rod bearings for me so that they would work with the dowels.
The cylinder heads will also be freshened up and I'll be upping the valve sizes from 2.08/1.6 to 2.160/1.65. No other needs there, no valve spring changes, etc. The same intake adapter/tunnel ram will be used and my only plan there is to change to an offset cup lifter so I can have a little more pushrod clearance. I used 3/8" diameter pushrods, but it would be nice to be able to run a 7/16" on the next iteration.
I will be using the same camshaft as I've always used as it's proven to be the money-maker. I did try another camshaft last Friday afternoon for giggles and it proved to not be as optimal. It was just a last moment quick-change and used essentially the same camshaft duration and lift, but a 2° wider LSA. It lost 20 hp and torque.
The new pistons will be domed to bump up the compression a little over 2 points and will feature .8mm rings. In conjunction, they are also gas ported so that I can use a vacuum pump. I don't quite think I'll hit 600 hp with the next iteration, but I'd like to get at least 575 hp out of her. We will see.
