1966 289...stock heads or 351W heads?

Scooter · 08-31-2003, 01:44 AM

I'd like a little more giddyup out of my pony. Would I see any benefit by putting early 351W heads on my mild '66 289? I already have a nice set - whattaya think?
TIA
-Don

MKmaverick72 · 08-31-2003, 01:51 AM

Bigger valves a little less compression,but definetely an improvment. Go with it.

66Mushoss · 09-01-2003, 08:02 AM

when you say early,you are meaning 69-73 castings?If the heads are later than that I don't think there would be any gain in using them.Also why not have them milled to keep your compression the same

tonys10sec306 · 09-01-2003, 12:35 PM

i would go with a set of 69-70 351w heads. same port and valve size as a gt-40 head. i have a set of 70 351w heads bowl work, port match the heads flow 197/175 the heads arent fully ported. a set of 289 or 302 heads would flow that number or a little more fully ported

[ This Message was edited by: tonys10sec306 on 9/2/03 12:37am ]

n2omike · 09-01-2003, 01:06 PM

It's not worth the hassle.

There's not a whole lot of difference in the ports of any regular production Ford head. You'd have to step up to the aftermarket for significant gains. Sure, the early 351W heads come with 1.84"/1.56" valves and have slightly larger intake ports, but still have an extremely cramped exhaust passage.

Any gain in flow with the 351W heads will be lost in compression. The 289 heads have 54.5cc chambers, while the 69-70 (C9OE and D0OE) heads measure 60.4cc on average. Later 351W heads are even larger.

The only 351W heads that won't totally kill the compression ratio are the C90E and D0OE 1969 and 70' heads.

Personally, I'd just do a little grinding on the existing 289 heads... either that or save for an aftermarket set.

Good Luck!

tonys10sec306 · 09-01-2003, 02:19 PM

mike is your times on motor or nos?

n2omike · 09-01-2003, 03:16 PM

My car weighs 3300lb w/driver, has a stock 4-speed, uses a pump gas 302 with 289 heads that I ported myself without the aid of a flowbench, stock cast iron crank, 289 rods and TRW pistons. The engine has a solid flat tappet cam (Comp 282S magnum lobe on the intake, 294 exhaust) measuring 236/248 @ 0.050", and is shifted at 6800 rpm. It has seen WAY more street than track time, and has proven to be very reliable over the years.

It still has the heater, wipers, stereo, lighted make-up mirror, carpet, etc. It was driven 100 miles each way to a cruise-in shortly before removing the engine.

Come race day, the pump gas gets replaced with whatever race fuel is available, and the bottle gets turned on.

The car is set up for nitrous, and ran the times below with it. I rarely get to the track, so most of the runs have been on the bottle. On the 1/8 mile, it did manage a 7.48 without the juice. It ran 6.74 @ 103 with the bottle on the 1/8 mile.

When the engine was 'fresh' it ran 6.74 @ 102 on a 150hp shot. As it wore, the nitrous was turned up to 200hp, and it ran the same et at 103. The day before I took the engine out, the pistons were slapping in their bores, but it still managed a 10.65 in the 1/4.

It's not an optimized race car, but does okay for what it is. It's just an old school truely streetable hotrod.

For the curious, on the way to the track (the last time where it ran the 10.65) the car got rear-ended. I still ran it, even though the rear frame was bent and it spewed gasoline out the back on every launch. I came home and did some 'end of the season' nitrous testing without the proper fuel. It was a bad idea, since a couple pistons decided to break off at their ring lands. I took it as a good opportunity build another engine, which will be up and ready this spring. The short block is ready, and awaiting me to finish porting the twisted wedge heads. It will also be a pump gas, street 302. The car has been on a frame machine, and is awaiting bodywork.

It was a pretty sucky weekend... going from a fully functional 10 second, fairly good looking mustang, to a crashed up car with a blown engine.... all in the course of two days!

After pulling the heads, I mailed one to a guy who wanted to use it as a model to port his. In exchange, he took it to have it flowed. With an old beat up valve job, the intake flowed 218, the exhaust 176.

Oh well, it won't be long til' it hits the road again.

Good Luck!

mstngjoe · 09-01-2003, 04:58 PM

Quote:

On 2003-09-01 13:06, n2omike wrote:
It's not worth the hassle........Personally, I'd just do a little grinding on the existing 289 heads...either that or save for an aftermarket set.

I totally agree!

Back in the day this swap made sense. Today it doesn't.

There are just too many alternatives. The after market is chock full of iron heads that will get the job done better and cheaper.

If nothing else, put the bigger valves in the 289/302 heads, do some home porting and gasket matching and you're there. Or close enough anyway.

I just read a post on another forum that claimed 45hp increase by dropping some W heads on a STOCK 289. Not gonna happen.

Save the your $$$ and go aftermarket. You'll be glad you did.

Scooter · 09-02-2003, 10:42 AM

Wow! Thanks for all the replies!

I guess I should give a few more details:

The car is a daily driver - not a drag car.

The motor is a 1966 4v 289 (not HiPo) w/ a Performer intake and Holley 600. Very mild street/towing cam (pretty close to stock).

My Windsor heads are 1969 C9OE gasket matched porting and new Motorsport valves/springs installed.

Switching to the 351 heads would drop my compression from it's current 10:1 to 9.2:1, but would increase flow. I wonder if the increase in flow would even be felt on the street? I suppose the loss in compression would cancel out any gains in flow.

Aargh....what to do?

-Don

mstngjoe · 09-02-2003, 11:21 AM

I'll admit to not noticing you already had the heads ready to go.

Go ahead and use them if you want, but IMHO, the butt dyno won't notice much difference, all things being equal.

adgdghr123 · 09-02-2003, 11:50 AM

Your wallet dyno, so to speak, might notice a difference though, seeing as how this is your daily driver. Lower compression means lower octane, a nice plus with current gas prices.

n2omike · 09-02-2003, 12:08 PM

If they're fresh and ready, you may as well. Just don't forget to use the proper intake gaskets and head bolts. The 351W heads are drilled for 1/2" bolts, so you'll need special 'shouldered' head bolts. These used to be available from Ford, and are available from other sources.

Check to see that the steam holes in the heads and block line up. The 289 block has it's steam holes directly above the cylinder bore toward the intake valley. You'll probably have to drill either the block or head with a 3/16" bit. Just use the head gasket as a guide, and drill either the head or block to match the other.

Good Luck!

blkfrd · 09-03-2003, 05:04 PM

We should publish this topic on the website somewhere since it comes up so often.

Bill Carroll's Ford V8 Performance Guide ( the Stockers Bible ) says: "which makes little or no difference because of lowered compression ratio" when 351w heads are put onto a 289 as part of his stage 2 upgrade to a 2 bbl 289. Stage 1 was an upgrade to an aluminum hi rise manifold and 4 bbl 600 cfm carb and a mild hydraulic cam. Stage 3 included hi compression pistons and stage 4 included a mechanical hipo cam which all together yielded 339 HP from the 289.

Stock, the 351w heads do outflow the 289 head on the intake side, but the exhaust side is the same or worse due to thermactor humps ( if you have post 65 289 heads, you have thermactor humps on them too ). More flow is possible from the 351w head than a 289 head if you are willing to port them. At a minimum, remove the thermactor humps from the exhaust ports. Fully ported, they'll flow just shy of 220 intake and 180 exhaust.

_________________

Tracy Blackford: Corona, Ca
Restoring '65 Fastback Mustang
329 with stage II 289 rods, KB 322 pistons,
282S cam, and race preped 351W heads.

[ This Message was edited by: blkfrd on 9/4/03 11:38am ]

mstngjoe · 09-03-2003, 06:24 PM

I can't believe I don't have that book in my library!

I'm gonna order it right now.

http://www.amazon.com/exec/obidos/tg...1137?vi=glance

_________________

[ This Message was edited by: mstngjoe on 9/4/03 6:38am ]