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Premium Member
1,160 Posts
Discussion Starter #1
I started this project Jan 1, 2010 with the power/drivetrain while building up the facility to order the car.

As it stands now, I have chosen to use the Factory Five Roadster for my 289 Buildup. I have decided to begin with the engine while I build up funds and facility for the build.

Since this is NOT a replica Cobra, (AC or Shelby), I am free to design and build as I like. And as I appreciate the use of the Ford 289 by an American in International LeMans racing, I wanted to do a modern 289 buildup for use in the Roadster. It would be a nice nod to racing history and appropriate to the vehicle, be an easy build, yet not creepily try to impersonate something it is not: an original Cobra.

So, in my research, and considering the environment of laws and regulations regarding assembled cars, I decided to use a 60's 289 engine. If I really wanted to lean toward building a copy, I would have held out for a '62-'65 block. But I read where the last Cleveland and later Windsor Engine Plants ran out of 289 blocks and finished the 289 production run using the new 302 blocks but with 289 internals. The first run of 302s blocks were reportedly higher in nickel content and slightly stronger in the lower block webbing, so I opted to look for a late 289. And 1967 was the last of non-federal emission control engines.

So today I found an 8/1967 289 engine that is probably a 302 block. Scored it on eBay with its original Ford C4 Auto Transmission. Entire assembly is unmolested so there's a chance the block is rebuildable. Plan is to keep the short block and sell off the peripherals. Rebuild with new heads, intake, cam. Would like to put out 400-425 hp and torque to net 350 both to the ground. We'll get her home and see what the numbers look like. Great start to 2010!

Premium Member
1,160 Posts
Discussion Starter #2 (Edited)
Engine Codes Deciphered

January 18, 2010 at 11:38 AM

OK. Here's the ID numbers from the engine. Carb and Tranny to follow later:

Cast on Block: C6AE-6015-C
C = 1960's
6 = 1966
A = Ford
E = Engine
6015 = Block
C = third revision
So its the 3rd revision of the 1966 block cast.

Date Code: 7H26
7 = 1967
H = August
26 = 26th
So it was cast on 26th of August 1967

Assembly Number: 7M8J
7 = 1967
M = December
8 = 8th
J = Inspector "J"
So it was assembled 8th of December 1967

Engine Tag Number:
289 / E/ 68 /16
M8 /K/ 236-J

289 = 289 CID
E = ?
68 = 1968 Model Year
16 = Change Level 16 (8/67-7/6/68)

M8 = December 8th
K = ?
236-J = 289, 2V, automatic

So in summary:
In the Windsor Foundry, using the 1966 3rd revision mold, on August 26, 1967, the 289 block was cast. It was assembled 4 months later on December 8th 1967 (using engineering revisions used from August 1967 and later ending July 1968 for a 1968 model year Ford Mustang, 289 engine, 2bbl carb, with automatic transmission.

Premium Member
1,160 Posts
Discussion Starter #3 (Edited)
Autolite 4100 Rebuilt.

Kurt Praxl of KP Carbs at http://mysite.verizon.net/vze2gsgu/index.html

Autolite 4100 1.12 4bbl longsnout with hot-air choke. Her 600cfm rating actually flows at 550.

There is a formula that will get you very close to the proper cfm for your engine. The formula goes like this:

cubic displacement divided by 2 (ex: 289=144.5)

maximum rpm divided by 1728 (ex: 6500 rpm=3.76)

multiply those two figuires (ex: 144.5 x 3.76=543 cfm)

Hold on we are not done. You now have to factor in volumetric efficiency. A Nascar race engine runs at 85%-90% volumetric efficiency. A normal street car wil be 75-80%, depending on what you have done with your heads and exhaust.

Ex: 543 x 90%=488cfm
Given 488+10% (536cfm) rating needed for this hi-flowing 289, and that the 4100 1.12 bench-flows at 550cfm, I think its a good match.

We'll be using a hot-air choke as she's already setup for it with her A/F calibrations.


Premium Member
1,160 Posts
Discussion Starter #4 (Edited)
Bucket list to date:

Settled so far:
Mk IV, T5 Manual, 3.55 IRS, Ford 289

Ford 289: C6AE-6015-C
289 / E/ 68 /16
M8 /K/ 236-J

Rotating Mass:
Bore: 4.020 in Stroke: 2.870 in
Fel-Pro Z2804 Full Gasket Set
Stock crank, caps.
Keith Black domed KB312 -3.00cc pistons w/Mahle Rings 3150034-025, 10.5:1 CR
Ford stock 5.115 con rods, press fit, polished and shotpeened, ARP 5/16 bolts.
Pro/Street 28.2 balancer
Ford racing 28 oz flywheel, King Cobra 10.5" clutch.
Autolite 4100 1.12 square bore longsnout with 1" phenolic spacer w/ pcv inlet
Weiand 8020 action-plus, dual plane, high rise intake
Trick Flow Twisted Wedge 170 Street aluminum heads w/ 2.02 and 1.6 valves, hardened pushrods, CompCams Ultra Gold Alum roller Rockers 19044-16, double timing chain.
CompCams extreme Energy retro-Fit Hydraulic roller Cam 35-421-8 as a 351W cam so the firing order will be the 351 order and take load off 1-5 front cap.
Electic fuel pump.
Electrical/Ignition: TBD
Exhaust: Under the car
Transmission: Tremec T5 with midshift upgrade 3.35-.68 OD, Pro5.0 T56 shifter

Premium Member
1,160 Posts
Discussion Starter #5 (Edited)
4/2011 update.

Well, just before the snow flew here on the Northcoast of Ohio, I acquired a few winter projects:

New (but abused) Tremec T5-Z liberated from Summit Racing for $500 and a S-10 T-5 for $65. When reconstruction is done next week, I'll have a:

2010 Tremec T5-Z with upgraded midshift (hardened machined steel selector plates and 1 piece finger), billet 1-2 & 3-4 keys, billet cluster plate, bronze reverse idler spacer and fork pads, both mechanical and electrical speedo conversion present.

Sorry if I sound bravado, but it's my first tranny build and I'm proud to say over-thought and over-built. It'll be a nice companion to the King Cobra clutch and 289 325hp/350Tq buildup in progress.

Premium Member
1,160 Posts
Discussion Starter #6
Engine Block and Tranny Work.

Well, dropped off the block to be baked and checked at Jeff Muzzi at H&W Machine in Barberton. Jeff came recommended by a trusted source who builds and races toyota motors.

Also ordered parts for the T5Z tonight. Looks like the T5Z will total out at $750. Not too bad for a new & hardened T5Z. Should be fun. Gotta start looking for a Pro 5 Shifter of T56 design and a ball.

Now its gut wrenching time until my machinist calls.

Premium Member
1,160 Posts
Discussion Starter #7 (Edited)
Cam Choice Revision

Can't justify 400% increase in cam setup for 4% HP return.

Dropping roller cam and lifters conversion of this old block for hydraulic cam setup. Yeah, I caved. But a smart decision I think.

From: Aaron Mick [mailto:[email protected]]
Sent: Friday, April 22, 2011 8:36 AM
To: Gaberial Ray
Subject: Jonathan Stone - COMPCams.com - Camshaft Recommendation Form
Camshaft Recommendation
Factory Five Roadster, 2000 lbs., Axle Ratio: 3.55, Ford 289-302 c.i. 8 Cyl. 1963-1995
289 c.i., Bore: 4.00 x Stroke: 2.87, 10.5:1, Rod Length: 5.155
Dual Plane Max Flow Weiand Stealth 8020, Trick Flow Twisted Wedge Street 170 as-cast
Intake Valve Size: 2.20 x exhaust Valve Size: 1.60, 1.6:1
Fuel Octane Rating: 93, Carburetor: 550cfm,
Power Steering? Yes, Power Brakes? Yes

I was recommended 35-421-8 XR270RF full roller setup. I need a hydraulic flat tappet cam alternative.
I think the 35-246-3 XE274H is a viable hydraulic flat tappet cam choice? Opinion + recommendation please. Thanks!

I like your recommendation. You have the flow and compression to go a little bit higher. You would be pushing it though with your vacuum restrictions.
I like your Flat Tappet recommendation over your roller in this case. More Streetable and still makes plenty of power
Gabriel Ray
Technical Consultant

COMP Performance Group™
3406 Democrat Rd.
Memphis, TN 38118
Toll Free: (800)999-0853
Fax: (901)366-1807
[email protected]

4,741 Posts
I don't know if you bought your shifter yet, but I bought one of these for my build. Haven't installed it yet but it looks very well made. I did a lot of research here and on the Mustang sites and MGW seemed a little better than the Pro-5. I'm also running a mid-shift / S-10 / T-5.

2003-2004 Cobra T-56 6 Speed for $179.00 (looks funny, but this is the correct shifter)

I'm also bought the silver (Race) handle, dust boot, and stang shifter gasket.


btw, your build plans sound very cool, can't wait to see that engine!

master craftsman
5,597 Posts
Sounds great so far!!! It'll be a great build.

Premium Member
1,160 Posts
Discussion Starter #10
Thanks guys.

Appreciate the suggestions. And haven't got the Pro 5 yet but will STRONGLY look at your suggestion first.

Premium Member
1,160 Posts
Discussion Starter #11 (Edited)
Midshift Conversion Speedo Rings arrived!

Well, got the parts back finally from my machinist.

While doing the T5 (with mechanical speedo pickup) conversion over to midshift, we acquired an S10 tail (but had an electronic speedo pickup). Since the mechanical and electronic pickups are in holes on different locations along the tail, we elected to keep the mechanical speedo gear on the shaft but build us a electronic speedo pickup for the S10 electronic speedo hole. With two speedo pickups on the shaft, we can change tails more easily.

We discussed gluing, pinning, drilling, etc all kind of ways to secure the tone ring on the output shaft but settled for a mild interference fit. The ring will never see physical action of any kind as it just spins in air past the magnetic pickup.

So to install, I plan to just heat up the tone ring and cool down onto the adapter ring. We bored out the tone ring enough to slip over the shaft splines. Made the adapter ring .004" larger than the tone ring internal diameter for a interference fit we could heat up enough to fit over the adapter ring. The adapter ring had to be split and we figured any gap helps make a squeeze fit onto the output shaft more possible than a complete ring.

I may use an adhesive between the shaft and bronze adapter halves since they are an exact fit, not interference. Haven't decided what to use yet.

I also had him burn up some bronze stock and make me a stop ring to replace the rubber o-ring. If the rubber fails, I didn't want the reverse idler touching the other gear. Eh, a longshot but while I'm in there...

I'll post a pic of the two rings and output shaft all together ASAP.

Here's pic. Any of this make sense?

Here's the reverse idler bronze bushing installed.

And the tone ring installed. The bronze is zero interference fit to the shaft but the tone ring is .004" undersized to the bronze. I added a touch of JBWeld to the shaft just for fun but the tone ring needed nothing but lots of heat to open it up for fitment. Tighter than a .... well, you add your own line here. It ain't coming off!


Premium Member
1,160 Posts
Discussion Starter #12 (Edited)
Tranny's done!

Ford Racing Super-Duty T-5 Transmission
Number of Gears Five
Input Shaft Diameter 1.062 in.
Input Spline Quantity 10
Output Shaft Spline 28
Output Shaft Spline D 1.500 in.
Tailshaft Length (in) 7.180 in.
Yoke Style Slip-on
First Gear Ratio 2.95:1
Second Gear Ratio 1.94:1
Third Gear Ratio 1.34:1
Fourth Gear Ratio 1.00:1
Fifth Gear Ratio 0.63:1
Case Material Aluminum

Upgrades: Midshift Conversion
Full Sized Output Sleeve Bearing
Billet Bearing Retainer
Billet Steel 3-4 Synchro Keys
Bronze Reverse Idler O-ring
Electronic Speedometer Tone Ring Added
CNC Selector Plates
Single Piece Selector Finger
Bronze 1-2, 3-4, and Reverse Fork Pads
All new kevlar rings and shims for zero endplay.

Total: $802.35

Premium Member
1,160 Posts
Discussion Starter #13 (Edited)
Cam Gear:

Comp Cams Live Chat Transcript

Gabe: Jon, how can I help you
Jon: Hello. I am using 35-246-3 XE274H cam in a SBF 289 with standard, blueprinted oil pump. What material is this cam made of and what is the right metal distributor gear for this cam?
Gabe: Cast iron gear on the cam
Jon: Thanks Gabe.
Gabe: Bye

Premium Member
1,160 Posts
Discussion Starter #14 (Edited)
Original Specs and what I'm considering in red.

1965 Shelby Cobra 289 CSX 2470
Year 1965
Make Shelby
Model Cobra 289 CSX 2470
Engine Location Front
Drive Type Rear Wheel
Production Years for Series 1963 - 1964
Price $5,995.00
Weight 2100 lbs | 952.6 kg

Engine Configuration V
Cylinders 8
Aspiration/Induction Normal
Displacement 289.00 CU IN. | 4736.7 cc. | 4.7 L.
Valves 16 valves.
2 valves per cylinder.
Valvetrain OHV
Horsepower 271.00 BHP (199.5 KW) @ 5750.00 RPM / 350bhp
Torque 312.00 Ft-Lbs (423.1 NM) @ 4500.00 RPM / 350tq
HP to Weight Ratio 7.7 LB / HP (Vehicles with similar ratio) / 6.0lb/hp
Bore 4.00 in | 101.6 mm.
Stroke 2.87 in | 72.9 mm.
Compression Ratio 11.00:1 / 10.5:1

Standard Transmission / Ford Racing SD T5Z
Gears 4 / 5
Final Drive 3.54:1 / 3.55:1

Fuel Capacity 18.0 Gal
Seating Capacity 2
Length 151.501 in | 3848.1 mm.
Width 61.001 in | 1549.4 mm.
Height 49.001 in | 1244.6 mm.
Wheelbase 90.001 in | 2286 mm.
Front Track 51.501 in | 1308.1 mm.
Rear Track 52.501 in | 1333.5 mm.
Ground Clearance 4.501 in | 114.3 mm.

Suspension Front : Independent / IFS Coil Over
Rear : Transverse-leaf suspension / IRS Coil Over
Pin Drive width, 5 lug wheels.

Rack and Pinion
Turns lock to lock 2.90 / 2.5
Turning Circle 34.5'

Front Brake Size 11.001 in | 279.4 mm.
Rear Brake Size 10.001 in | 254 mm.

Tires / Wheels
Tires Front : Dunlop SP41 HR 185x15 / 235/60/15 front
Rear : Dunlop SP41 HR 185x15 / 295/50/15 rear
Construction Tubeless Rayon/Steel
Load Capacity 1480 @ 36 psi
Overall Diameter 26.50"
Tread Width 6.25"
American Racing Torq-Thrust D Gray Wheel

Premium Member
1,160 Posts
Discussion Starter #17
Head changeout.

Well, a little later than desired but after I decided to shift from a roller buildup to a hydraulic flat cam buildup, I forgot to change out the heads. They were TFS-51400004 Trick Flows for hydraulic roller tappets. Totally different tappet/cam alignment.

So I changed over to TFS-51400002 heads for flat tappet. This also changed the springs from dual spring, 425# open to single w/ damper 325# open. Less to worry about insofar as valvetrain pressures. Glad I caught it before installation!

Premium Member
1,160 Posts
Discussion Starter #18
Conversation with Comp Cams on Cam Break-In.

Live Chat Transcript

Chat start time Jan 5, 2012 9:15:14 AM EST
Chat end time Jan 5, 2012 9:24:25 AM EST
Duration (actual chatting time) 00:09:10
Operator Mick

Mick: How may I help you today?
Jon: Hello. Can I ask a Cam break-in question?
Mick: Yes sir you can
Jon: Thanks. New SBF engine build. I have a new #35-246-3, a XE274H cam. Am using new Trick Flow heads with single springs of seated 110# / open 310# pressure. Regarding break-in, are these spring pressures extreme enough to have to change to lighter springs for break-in? Or do I have to find SBF break-in rockers? Or am I OK to run the head as-is and just use break-in oil and proper RPMs?
Mick: Those spring pressures will be fine to break the cam in with. Just be sure to follow proper break in procedures and use a high zinc break in oil.
Jon: Outstanding. Thanks Mick!
Mick: You're very welcome

Premium Member
1,160 Posts
Discussion Starter #19 (Edited)
Revised the heads again...

Well, Trick Flow only offered the 51400002 170 Fast As Cast 61cc heads. But now offer the same head but in 58cc version with CNC chambers as 51410002-M58. Downside is going from tungsten seats to ductile iron.

Keeping the Keith Black 3.00cc domed pistons.

At least now I can get a solid 10.48:1 ratio!

Premium Member
1,160 Posts
Discussion Starter #20 (Edited)
Grrrrr. Cam change again.

For the 289 SBF and subsequent production, I chose the use the most effective Comp Cam profile; and XE274H grind.

But after listening to all the Internet sound files of SBFs with this grind, its too lopey for me. I'd go nuts anticipating an engine stall. Especially in traffic. And I'd have to have a higher idle speed.

So I'm stepping back one notch to an XE268H grind. Very occasional lope, fairly smooth, I'd lose 3% of the power on the top end but I think for a nice idle in a frequent driver that's acceptable. I may not make my 350/350 goals, but its arbitrary anyway.

Here's the 268 grind:

Here's the 274 grind:
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