302 Rebuild

[07cob]

After 20000km/3years, the powerplant in my Cobra is now undergoing a makeover. The engine is a stock EFI 302 from a late 80s/early 90s Mustang. The main purpose for the upgrade is to move away from the *modern* engine look and back to a traditional look. In doing this, there will also be a modest power upgrade - nothing too wild though.

A list of planned modifications is as follows:

Trickflow heads and associated valve gear, including cam for a lttle extra ooomph.
MassFlow EFI - to give the traditional look
Standard rotation water pump to remove the original belt tensioner
Polished alloy drive pulleys for the looks.
Single wire alternator

To achieve all these with the greatest of ease (?) I have decided to remove the engine and attack it all on a stand. Hence, there are a few additional items I can attend to:

Rear main engine seal (slight leak)
Sump gasket
Low oil sender unit leak - oil temp sender to be installed
Gearbox rear pinion seal (I think) leak.
R32 diff pinion seals (LSH has slight leak)

As well as this, I am going to attempt (no guarantees yet!) to clean up the engine bay so that the engine itself is the centre of attention (rather than all the ancilliary components like wiring and hoses etc).

That should just about do it!

Here is the engine as it was first installed:



and here is the trial fitment of the MassFlo intake and EFI setup. I wanted to do this before removing the engine to check clearances.



As this rebuild progresses, any and all advice or general comments gratefully accepted.

More details will follow as works progress.

Regards


Geof

[boxhead]

A much nicer look.

[Merv and Sharon]

Looking good Geoff. Smart to test clearance for air cleaner first! They can be tricky. Did u get roller rockers as well?

[BJ's Snake]

Exactly what I wish to do so will be watching with great interest.

Cheers

[07cob]

Originally Posted by Merv and Sharon

Looking good Geoff. Smart to test clearance for air cleaner first! They can be tricky. Did u get roller rockers as well?

Merv

Yep, roller rockers and everything else that was on your shopping list!

The air cleaner has plenty of clearance. In fact, enough that I can get a larger element that is 4" tall and still have clearance.

Geof

[Merv and Sharon]

My air cleaner height was fine but at the rear I had less than a cm of clearance and that was achieved by offsetting the main shaft from the MasFlo throttle body.

[bobcowan]

You're going to put a new top end on a 20+ year old bottom end. That's fine if you plan on doing this job again in a couple of years. If you want to do it once and forget it, you should consider a new bottom end.

Twisted wedge heads make good power. But sometimes need special pistons to match the differant angle of the valves. Not always, but sometimes.

Better heads with bigger valves and a matching intake for air more flow; can be an excellent idea. Planning on a new cam? If not, you won't see the full potential of the heads and intake.

Stock iron heads have a combustion chamber of about 60-62cc, and you get a compression ratio of about 9:1. The TW heads have a chamber volume of 64cc exactly. Bolting them on to a stock bottom end will cost you compression. Compression is what makes power. Consider a head with a smaller chamber, like 58-60cc. If not, be very carefull about cam selection.

Maybe the $$ don't match up where you live. But here in the USA, it's usually quite a bit cheaper to buy a ready built crate motor, rather than try to rebuild what you already have. A lot faster and easier, too. Unless, of course, your buddy owns a machine shop and will do all the work for a case of beer.

[Mando]

You've done a great job on the engine bay Merv it really looks the part.

Regards.

[Merv and Sharon]

Thanks Mando - Peter Hancock was the man with the plan.

[blykins]

Which Trick Flow heads are you using? Keep in mind that if you use a twisted wedge head, that you'll need different pistons.

Also, keep an eye on piston/valve clearance. Those 5.0 engines don't lend much in the way of room and if you go much over .500" lift, you'll run into some issues depending on the camshaft.

While you have it out, it would be a really good time to put new rings and bearings in it, along with gaskets and a rear main seal.

[07cob]

bobcowan

Thanks for the reply. Unfortunately, a crate motor is not really an option with our registration requirements.

Here is the TrickFlow heads and matching cam that will be installed:

Trick Flow® Twisted Wedge® 170 Cylinder Heads for Small Block Ford: TFS-51400004 - trickflow.com
Trick Flow® Track Max® Hydraulic Roller Camshafts for Ford 5.0L: TFS-51402000 - trickflow.com

This combination has been used on a few engines over here with some very good results. Bear in mind, I am not trying to make a big HP engine – just a slight upgrade from stock.

Originally Posted by bobcowan

The TW heads have a chamber volume of 64cc exactly

The TrickFlow website quotes 61cc for the 170s.

Originally Posted by bobcowan

You're going to put a new top end on a 20+ year old bottom end. That's fine if you plan on doing this job again in a couple of years. If you want to do it once and forget it, you should consider a new bottom end.

What would you recommend for the rotating assembly?

Cheers


Geof

[07cob]

blykins

Thanks for your thoughts.

Originally Posted by blykins

Which Trick Flow heads are you using? Keep in mind that if you use a twisted wedge head, that you'll need different pistons.

Also, keep an eye on piston/valve clearance. Those 5.0 engines don't lend much in the way of room and if you go much over .500" lift, you'll run into some issues depending on the camshaft.

The heads are TrickFlow Twisted Wedge 170s (PN: TFS-51400004).

These have been used on a few SBFs here with no change of pistons.

TrickFlow website also states, “Trick Flow® Twisted Wedge® heads are the only aftermarket heads that can run 2.020 in./1.600 in. valves with stock, unmodified pistons and performance camshafts up to 0.550 in. lift” (Trick Flow® Twisted Wedge® 170 Cylinder Heads for Small Block Ford: TFS-51400004 - trickflow.com)

Regardless, I will heed your advice and check the clearances carefully.

Originally Posted by blykins

While you have it out, it would be a really good time to put new rings and bearings in it, along with gaskets and a rear main seal.

Thanks, I am tending towards doing at least the rings and bearings while the engine is out. Also, every (?) gasket and oil seal will be replaced.

Cheers


Geof

[Merv and Sharon]

I always planned that if the bottom end of mine ever goes (and it tested out fine) I would get a new block from Ford Racing here and notify Qld Transport. At least I was advised that could be done.

[bobcowan]

The problem here is that you get into the "While-I'm-At-It" syndrome - something I'm intamitly familer with. While I'm at it, might as well do rings and bearings. Cam. Lifters. Oil pump. pistons. Crank. etc. Before you know it, you'd have saved time and money by simply installing a new or rebuilt short block from your favorite rebuilder.

You're not really asking much - a simple inexpensive and fun street machine. Your stock engine probably makes around 200-220 hp. Adding another 100 to that with a rebuilt engine is pretty easy, reliable, and inexpensive.

There are lots of short and long blocks available that will do exactly what you're looking for. Ford is a good source for a long block, as you can get them locally for a good price, and they have a warrenty. Pretty hard to beat that. Their cheapest long block makes 340hp, and has a very flat torque curve - $4,000 USD.

Ford Racing Performance Parts

[Philm]

Geof,
Sounds like a lot of fun.

It may be a good idea to check cylinder pressures, not sure what a stock 302 should be but you are really looking for a similar number for all cylinders.

I would look at rebuilding the bottom end, or swapping it for a new one.

I would add to the list, timing chain set, lifters and maybe push rods to ensure rocker geometry is correct.


Phil

[Merv and Sharon]

Pretty sure Geoff has all of those Phil. I did as well. Also checked cylinder pressures. The only other thing I would do, if again, is bore the block to 331 which I am told, gives great balance.

[blykins]

Boring the block won't increase the cubic inches by that much, neither does it affect the balance.

Even a .030" overbore 302 only adds 4 cubic inches.

Going to a 331 requires a stroker crankshaft. You can have the current rotating assembly balanced to make it smooth as butter.

[Merv and Sharon]

True Phil. I meant to say I would over bore a bit and and stroke to 331 or close to that.
For now I am extremely pleased with the power and balance of the set up. Large 30lb injectors create a challenge for the computer chip in metering at low revs.

[Merv and Sharon]

Sorry Blykins!

[blykins]

Very true.

When you find yourself having to grind a crank or resize rods, it's often more cost effective to buy the new stroker crank and rods.