The SBF 306 Engine Build - Updated 09/25

Paul · Nov 25, 2007

Today is the official begin date of my small block Ford 306 engine build for my 1989 Mustang coupe. It is a budget build with relatively simple and not-that-expensive parts in it. This is the first time I've built an engine completely from scratch, so I'm excited to do and I'm sure I will learn a lot along the way.

The bottom-haf components are as follows:

Production 5.0 (302) block, borded .030", align honed
OEM Crank, ground .010, polished, oil holes chamfered, balanced rotating assembly
Probe forged I-beam rods
Probe forged pistons, 4.030"
Clevite 77 main and rod bearings
Sealed Power gapless moly piston rings, 4.030"
ARP main and head studs
ARP harmonic balancer bolt
OEM harmonic balancer, 50 oz imbalance
Centerforce Billet Steel flywheel, 50 oz imbalance
Double roller timing chain
Trick Flow Stage 1 camshaft (.499"/.510" lift, 221/225 degrees duration @ .050" lift, 112* Lobe Separation Angle)

Well, I stayed up late last night mocking up the entire rotating assembly with a buddy of mine and checking tolerances on the main and rod caps with plastigage. I also checked crankshaft endplay. My tolerances so far are as follows:

Main cap oil clearances:
Cap 1: .0015"
Cap 2: .0015"
Cap 3: .0015"
Cap 4: .0015"
Cap 5: .0015"

Crankshaft endplay:
.0038" (a little tight, spec is .004" - .008", but I will live with it. It should open up immediately upon startup and the first time I push the clutch)

Rod cap oil clearances:
#1 - .0015"
#2 - .0015"
#3 - .0018"
#4 - .0018"
#5 - .0013"
#6 - .0015"
#7 - .0018"
#8 - .0013"

This morning I plan on a trip to Harbor Freight to buy a couple tools that I need, specifically a brass hammer, plastic hammer, and engine brushes. Then I'm going to clean the block and parts like crazy... twice. My buddy (a machinist) is bringing over his micrometers because I want to check the main and rod journal sizes just for good measure. I hope to assemble the entire bottom half of the motor today, and maybe even check piston-to-valve clearance as well. I already have a bunch of pictures, and I'll try to post them later today.

Paul.

AaRoN · Nov 25, 2007

Re: The SBF 306 Engine Build Begins Today - 11.24.07

Sounds like a good build. Keep us updated.

Paul · Nov 25, 2007

Re: The SBF 306 Engine Build Begins Today - 11.24.07

Blast! I was foiled this evening. I've got the crankshaft in, and after looking all over town for a ring installer tool, it turns out I have the wrong size piston rings. Looks like my pistons won't be installed until next weekend.

Paul.

Paul · Nov 26, 2007

Re: The SBF 306 Engine Build - Updated 11/25 with Pics

Here's some pictures from what I've done so far:

Here's the block after I masked it all off and painted it cast iron grey.

This motor had OEM main cap bolts, so I replaced them with these ARP main studs for a little extra strength.

This is my friend Mike (he's a CNC machinist by trade) chasing threads on the block while I was cleaning the crankshaft out.

Croke%20Chasing%20Threads%20(Medium).jpg

Here's the crankshaft (OEM) and Trick Flow Stage 1 cam.

Here's the pistons, rods, flywheel, and balancer. In that picture you can also see my oil pan and headers that I blasted with steel shot. Those will get powdercoated later.

This is a picturing of the plastigage measurement on one of the main caps.

Here's me torquing down the main caps to 70 ft. lbs. for the last of many times.

Here we are setting up the dial indicator to measure crankshaft endplay. When I did this the second time, I used my magnetic base instead of the clamp - it was easier.

To measure endplay, you set up the dial indicator, zero it, then move the crankshaft forward and backward with a prybar. Endplay should be .004" to .008" - the reason I took this motor apart was because endplay was .131" ... seriously. The crank moved so far forward when I pushed the clutch that the flywheel would actually hit the inspection plate on the bellhousing.

That's all for now. More to come later.

Paul.

Dalamar · Nov 27, 2007

Re: The SBF 306 Engine Build - Updated 11/25 with Pics

cool man! good luck with the assembly.
nice pix

realitygt · Nov 28, 2007

Re: The SBF 306 Engine Build - Updated 11/25 with Pics

finally, someone posts enough pics

I like when people post alot of pics and give detailed info about what they're doing.

Paul · Nov 29, 2007

Re: The SBF 306 Engine Build - Updated 11/25 with Pics

Okay, so last night I checked the ring gap, here's what I came up with:

Piston #1
Top Ring: .016"
Second Ring: .016"

Piston #2
Top Ring: .016"
Second Ring: .016"

Piston #3
Top Ring: .018"
Second Ring: .016"

Piston #4
Top Ring: .018"
Second Ring: .016"

Piston #5
Top Ring: .018"
Second Ring: .017"

Piston #6
Top Ring: .018"
Second Ring: .016"

Piston #7
Top Ring: .016"
Second Ring: .014" (was .016" down in the bore)

Piston #1
Top Ring: .020" (was .018" down in the bore)
Second Ring: .016"

So this is basically what I did:

First, remember these important words of wisdom... For safer engines, always use a condom.

And since I'm a bit paranoid, I always double bag it. O0

The first thing you need to do if you want to make this easy on yourself is buy a piston ring installer. This little tool makes it really easy to pop the rings in the grooves without scratching the crap out of the side of your ring lands. I picked this one up from Pep Boys for six bucks.

Then you need to figure out which rings go where, and how they're oriented. The ones with the shiny edge are going to be your top ones. Here is a crummy picture of the edge of my top ring.

Next, you have to keep in mind that there is an "up" and "down" side of the ring. You'll notice in this picture below that there's a tiny white circle on the ring. That circle means "this side up." On the second ring it's not as easy to see. Mine looked like a dent more than a dot.

Once you got that figured out, you can measure ring gap. This is actually really easy. All you need is a set of feeler gauges and one of your pistons. First, squeeze the ring into the bore. Be careful to not scratch the hell out of your bores with any sharp edges.

Then, take your feeler gauges and see what the largest one that you can squeeze in the gap is.

Then, using your piston to square up the ring to the bore, push the ring down a couple inches into the bore so you can take another measurement with your feeler gauges.

If you're satisfied with your ring gap, then you can install them on the pistons. Make sure to install the rings "180 apart", meaning that if the gap is on one side of the piston for the top ring, put the gap for the second ring on the other side. Also, when installing your oil rings, make sure that the ends are butted up against eachother, not overlapped. My rings came with painted ends to help you make sure they're seated appropriately.

So, that's really all there is to it. In the next installment, I'll post some pics of installing the pistons in the block. This is pretty simple though, you just need a ring compressor and a plastic hammer. You can see my one-piece 4.030" ring compressor in this picture - it is quite a bit easier than the weird ratcheting ones you can rent at the parts store. So, with that - here's a picture of all of my pistons with the rings installed and the tools I needed to do it.

More to come later. I'm really hoping to have the shortblock completed and the cam degreed this weekend.

Paul.

TRUUBLE · Dec 1, 2007

Re: The SBF 306 Engine Build - Updated 11/28 with Piston Pics

Looking good! :thumb:

Black97GT · Dec 1, 2007

Re: The SBF 306 Engine Build - Updated 11/28 with Piston Pics

Cool man! Loving the step by step updates.

fixthedoor · Dec 3, 2007

Re: The SBF 306 Engine Build - Updated 11/28 with Piston Pics

Very nice. :thumb:
Thanks for taking the time to take and post pics and provide a detailed write up.

Jrgunn5150 · Dec 3, 2007

Re: The SBF 306 Engine Build - Updated 11/28 with Piston Pics

Very nice, you rule Paul! Alotta guy's will find this immensly helpful!

MysteryMachine · Dec 3, 2007

Re: The SBF 306 Engine Build - Updated 11/28 with Piston Pics

I'm thinking about doing a 306 now myself so this will be good for me to watch and learn a bit. Not sure if I'm using my stock block or not yet though. Thinking in the future if I get the hp bug to throw a turbo at it so I need to take that into consideration

Dairy King · Dec 10, 2007

Re: The SBF 306 Engine Build - Updated 11/28 with Piston Pics

What heads, intake and all that good stuff are you goin with? How much horsepower do you think this will make? Im looking at a 306 right now actually and hope you can help me a little bit.

Hybrid Freak · Dec 24, 2007

Re: The SBF 306 Engine Build - Updated 11/28 with Piston Pics

Nice build! One day I will be able to build my own engines too.

Paul · Feb 10, 2008

Re: The SBF 306 Engine Build - Updated 11/28 with Piston Pics

Well, it's been a while since I've updated. The entire longblock is now built, the cam is degreed and installed, and the valvetrain is completely assembled.

Today, I began bolting up the timing cover up.

Here's my timing cover that I powdercoated last weekend.

I used a seal installer to put the front seal in without messing it up.

Then I carefully trimmed the timing cover gasket so it wouldn't show too much once it was installed, and applied a thin bead of RTV.

Once that had "set up" a bit, I installed it on the block.

Then I put another thin bead of RTV on the timing cover and installed it on the block.

I also put some JB Weld in one coolant passage on the timing cover because it was pretty badly pitted. I'm going to let that harden overnight, and tomorrow I'm hoping to install the water pump. I might do the oil pump and oil pan as well.

Paul.

AaRoN · Feb 10, 2008

Re: The SBF 306 Engine Build - Updated 11/28 with Piston Pics

Very nice Paul :thumb: That timing cover looks good.

94Pro-5.0 · Feb 11, 2008

Re: The SBF 306 Engine Build - Updated 11/28 with Piston Pics

nice build :thumb:

very professional

Paul · Feb 11, 2008

Re: The SBF 306 Engine Build - Updated 02/10 - Water Pump and Oil Pan

Okay, so I made some progress today. I'm trying really hard to get everything mocked up so I can order some additional fasteners and make some progress.

I put a thin bead of RTV on the water pump gasket, and squished it on the timing cover.

Then I attached the water pump. This thing is a behemoth - it weighs TEN POUNDS. :idiot2:

The stupid studs are ugly and a pain in the ass. I had to run a die over all the threads and a tap through the flange nuts to make them thread easily.

Anyway, then I flipped the motor over and installed the oil pump. Always remember to take cover off the oil pump, and inspect the gerotor and casting for any nicks or burrs. The last one I got had a huge nick in it and I returned it. Then I installed the oil pickup, and re-used my one-piece oil pan gasket. I hope this damn thing seals. I put a dab of RTV in the corners for good measure.

The I put the pan on - this was the one I powdercoated a while back in flat black. I love the way the finish turned out. I tightened down the bolts in two torque sequences, 9 and 15 ft. lbs., starting from the center and working my way out.

Later on I realized that I forgot to put anti-seize on ALL the oil pan bolts, so I have to take it back off and re-do it all over again. :slap: Dammit.

So, I began trying to figure out how the hell the damn fox bracketry goes together - I've been workong on SN95 5.0s for so long that I forgot. :crazy2: I eventually figured it out and started measuring bolt pitch and length. I obviously don't have all the correct fasteners here either, so I'll be ordering them as well. The former owner wasn't very good about retaining all the OEM fasteners.

You can also see in this picture how much I had to cut up the factory steel bracket to make it clear the Meziere water pump.

Here's from the top of the driver's side.

So, that's all for today. I have all the driver's side brackets and fasteners figured out, so now I just need to mock up the passenger's side and figure out those bolts as well. I'm hoping to do that maybe tomorrow night, and get the bolts ordered.

This weekend I really need to powdercoat a bunch of stuff so I can continue with the assembly.

Paul.

Paul · Feb 13, 2008

Re: The SBF 306 Engine Build - Updated 02/13

I spent three hours in the garage tonight sanding and smoothing my accessory brackets down so that the finish will be nicer when I powdercoat them this weekend. Last night I finished mocking them all up, and I got all of my remaining fasteners ordered. Hopefully they'll be here once I have the brackets coated so I can bolt them up.