How To Build A Budget Mustang 289 - Part 1

Marvin uses a lifter puller to remove stubborn hydraulic tappets. They're stuck due to wear and carbon deposits.

Checking the lifters with a straight edge, Marvin finds normal yet excessive wear at the lifter/cam lobe contact point. Lifters don't ride cam lobes head on. They ride on one side where the lobe spins the lifter to promote even wear.

This is typical cylinder wall wear at 150,000 miles, with a ridge at the top of the bores where the compression rings don't make contact with the cylinder walls. Note that the dished pistons are used to reduce compression in 289-2V engines. Four-barrel engines have flat-top pistons for increased compression.

One of the first things Marvin does during teardown is measure everything, beginning with cylinder bores. We allegedly have a standard bore block, and the bores check out at 4.000 inches and change. Marvin's going to bore and hone to 4.030 inches.

We expected to see a lot of sludge in the oil pan from 42 years of use. It was surprisingly clean aside from pieces of crumbling valve seal. This is what regular oil changes will do for you.

When Marvin removed the camshaft, he wasn't surprised by the excessive cam bearing and journal wear. Marvin tells us you can change your oil frequently, but mileage and run time take their toll. Every time you start an engine, you have a brief period of dry surfaces void of lubrication. Those are the moments that contribute to engine wear.

Look at the damage to the No. 1 cam bearing. The bearing has separated. Had the engine not been torn down, this separation would have eventually contributed to engine failure due to low oil pressure and metal fragments.

The news gets worse when we look at all five cam bearings. We showed you the No. 1 cam bearing. Moving to the rear of the engine at the No. 5 journal, oil starvation has been significant, with complete bearing failure. A fundamental truth is that engines won't last forever even with frequent tune-ups and oil changes.

The cam lobes are worn significantly because the greatest engine friction happens here with flat-tappet engines. If oil gets excessively hot, it starts breaking down and damage can happen quickly, even though nothing seems abnormal outside. That occasional clicking rocker arm is a hint of what's going on.

Piston, ring, and bore wear is about as expected. We have a high-mileage 289 that's ready for a teardown and rebuild.

The wear patterns on the connecting rod bearings indicate oil breakdown from excessive heat and insufficient oil wedge. And this engine got a lot of oil changes. Imagine if it hadn't.

Strip Castings BareBlocks and heads should go to the machine shop buck naked, void of freeze and oil gallery plugs. The very first thing your machine shop should do is inspect and measure the block. If 289 bores check out at 4.040 inches or beyond, discard the block. If you must reuse the block because it is a matching number piece, it can be sleeved for approximately $100 per sleeve or $800 on average. If you're building an engine for performance, find a good block. The block must also be inspected for cracks and other non-repairable flaws.