What cam? What heads? What manifold?

[Dangerous Doug]

Getting ready to have my 1965 289 freshened up, and I'm changing the cam, heads, and manifold. I've vacillated on my choices, but am currently thinking a Lunati "Voodoo" camshaft + lifters, a Weiland "Stealth" intake, and Ford Racing aluminum GT-40 "turbo swirl-X" heads.

What are rest of you small block guys running, and what kind of horsepower/torque are you getting out of your car? Also, if you had to do it all over again, would you do it the same way?

Thanks in advance,
Dangerous Doug

[blykins]

It's the question of how much horsepower you want....

What are you shooting for? 300? 400?

You wanting to use original solid type lifters? Or do you wanna go with roller this time?

I'm using a Comp Cams hydraulic roller. I love it. I wished I would have went with the next cam up though, as it doesn't match my Vic Jr. single plane intake very well.

I'm using Vic Jr. heads. I'm making 484hp and 500 lb-ft....with the cam change and a little head work, I should be able to pull a lot more out of the engine. Of course I'm at 425 cubes.

Did you get your block to the machine shop? What compression you planning on running?

Like I said earlier, tell us how much power you wanna make...that will help us make a better selection of parts.

[niles]

Blykins reply is right on.
After you settle on hp, and how much you want to spend, recommendations will flow.
I believe there are a better combination of components
gn

[Tongue Pirate]

DD,


Depends on what you want out of your motor but my little 289 sounds pretty sweet & feels pretty swift on it's feet(though I haven't "really" put it on the street yet). I used the Comp Cams "Nostalgia Plus" Hydraulic Cam & an offy 360 manifold with a 600DP carb. Other than that it's pretty much stock other than the girdle on the bottom, roller tip rockers & arp bolts throughout. Had my budget been a little larger I likely would have gone forged pistons & aluminum heads. The nostalgia plus cam has a mean little lope but not so much that it sounds out of control & the lift is such that you really don't have to worry too much about clearance problems. But like I said before it really depends on what you are after.

[Dangerous Doug]

I figure I'd like to get over the 400 bhp mark. I don't mind a loppy idle.

Compression ratio targeted is 10.5:1. This is a function of TRW 12.5:1 forged pistons that I already have, and adding large chamber heads (GT-40 heads have 64cc volume, should get me to 10.5:1). I'm figuring on a hydraulic roller, with roller rockers.

Suggestions?

DD

[blykins]

DD,

I don't mean to harp....but I really would have the block gone through....it would be a complete shame to trash a motor with all new parts because of something easy to take care of....You'd hate to see that motor start smoking after 500-1000 miles because the rings are gone and the cylinders are oblonged and tapered....or trash a set of bearings because the mains aren't aligned.

With that being said, you're pretty limited to cylinder heads if you're planning the compression ratio around the pistons. I don't know how many different sets of heads have 64cc chambers...but you will need some pretty decent heads to make 400hp with 289ci. My Vic Jr's are 60cc's....

Now that we've established how much horsepower, at what rpm range are you looking to make it? I think 289's are generally revvy motors.....

When you figure out if you're going for low rpm stump pulling torque, or you'd rather have high rpm horsepower, then we can recommend a cam and intake manifold to match.

Comp makes some great hydraulic roller cams....the largest one they make off the shelf peaks at 6500.....and that's generally what you'll see as an rpm limit with hydraulic rollers. If you wanna go above that, you'll need to look into mechanical roller cams or solid flat tappet cams.

Give us an rpm range, and we'll zoom to the next step.

[Tongue Pirate]

400! Wow! MY 289 is likely under 300 & it has some kick in this car! 400 ought to keep ya scared!

[Dangerous Doug]

Tongue Pirate: I drove a SPF with a stroked 351 running about 400 hp (or so the dealer said). Very nice. I was a passenger at a local autocross in another Cobra with a 425 bhp 428---and THAT, my friend, was scary fast. Holy cow! Don't need to go completely crazy, but I do want to make it scary enough to keep my wife from wanting to drive it. (heh, heh...)

Blykins: I'm having the engine gone through by a local mechanic that used to drive GT-40's for Shelby way back when. Stubbled across this guy getting my wife's Volvo fixed a while back. I'm putting in fresh bearings and rings. The pistons are forged TRW's, and seem to be in good shape, BUT we'll certainly take a look at the pistons, rods, and crankshaft for any weaknesses. There is no tapering or lip on the cylinder walls, so I'm thinking this had very few miles on it. No scoring, either.

Harping? Nah, I hadn't clearly stated what I meant by freshen up.

No stump puller for me. The Cobra is a light car at 2400 lbs. so my focus is on high-end horsepower. Top speed and quick acceleration are what get my adrenaline going.

I want a street drivable Cobra, but when I take it down to Laguna Seca to do hot laps I want to fly. And yes, I'm planning on the big brakes for the ERA...

So, peaking at 6500 sounds reasonable. 400 bhp is the figure stuck in my head, though that may be skewed slightly high since I was first going to do a 427/428 Cobra...

Dangerous Doug
With a handle like "Dangerous Doug", I need to have something that sounds menacing...

[Tongue Pirate]

Or to back it up Sounds like fun!

[blykins]

The GT40 heads may be a good size for you....you don't need terribly large valves with that displacement.

If you wanna go with a hydraulic roller, the Comp Cams cam that I mentioned would work well for you I think. Then I remembered that I have a 351 and you have a 289....hehehe....the firing orders are different I think...therefore you couldn't use the cam I had in mind.

However, this cam should work well for your application...

Comp Cams 31-452-8.

You'll need a "spider" for your lifters....

If 6500 revs is adequate, an Edelbrock Performer RPM Air Gap should fit your needs nicely.

If I get a chance, I'll run your combo through Desktop Dyno 2000 and see what kind of numbers we get. I have quite a bit of faith in it....it's been right for me several times.

[blykins]

DD,

I ran some numbers....I couldn't find any flow numbers for GT-40X, so I used some ported GT-40P heads that I found....the numbers are around the same as Summit Racing shows 240cfm at .550 lift.

I used an RPM Air Gap dual plane intake with the cam I spec'd above, roller lifters, and a 650cfm carb. 10.5:1 compression.

436hp @ 6000 revs
409 lb-ft @ 4500 revs

It does seem a little optimistic, so I think the flow numbers for the heads were a little above average....

But I think you should see 400hp or a touch over with this combo.

[JustOne]

You won't get anywhere near 400hp with GT40 heads stock or ported. The Vic jr also come in a 70cc head that the boosted cars run.
Here is some head flow data, some are ported and some are not.

http://64.233.179.104/search?q=cache...+wedge+R&hl=en

[blykins]

Don't be so sure....

Ford Racing has a 302 crate engine that makes 345hp with a very mild cam, and 9:1 compression.

I think you could touch 400 hp with the right combo of parts.

When I plug their cam specs and compression ratio into Doug's engine on Desktop Dyno, I get about the same horsepower that they are claiming.

[JustOne]

You can do if you spin the motor to 7500 and have a 12.5:1 motor, but it will not be streetable on pump gas. Going from 9:1 to 10.5:1 is about 15 - 20 HP. You can also go biger cam, but the heads just don't flow enough to justify the drivability. I would go with the AFR (you would have to change pistons) or the smaller Canfields or Brodix for this combo.

[blykins]

Like I said earlier, I grabbed some flow files that were of ported heads....but honestly, they weren't all that far off.

Desktop Dyno was around 4 hp off on my engine. That's pretty stinkin close. It's a very good tool for engine building if you have the correct information to put in it.

I'd say 400 or dangerously close to it is possible....

But of course I may be wrong. I usually am at least once a day.

[Shiloh4065]

Just went through a similar exercise with my Unique 289 FIA and my 1987 302 motor, a roller cam HO motor that is basically stock. The 87 motor has forged pistons, slightly dished. You need to talk to people who build race cars & motors, get their opinions, and then filter opinions to get to where YOU want to be on HP and driveability. Pure race, drag strip, or primarily a street cruiser, with some serious reserve HP??

A couple of names. The best 'carb guy' I've come across is a guy in Washington State, Don Gould. Builds race cars, loves small blocks, and personally runs a 318 Mopar that puts out over 400 HP for drag racing. Don sells Demon carbs, but more than selling them, he personally takes them apart, insuring everything is 'right', and will baseline the carb based on your motor, cam, car weight, rear end, etc. Comes pre-tuned. He will also talk you or your mechanic through the process of recurving your distributor and setting the correct timing. Don's web site is www.4secondsflat.com and his phone is 503 627-0728. He has helped a lot of cobra owners by helping with carb adjustment, etc.


Don recommended a "cam guy" to me, Jim Dowell, of Racer Brown in Maryland. Don will go through similar exercises as Don, and he will custom grind a cam for you at the same price as the stock off the shelf cams from the big name companies, but he will be able to offer more custom service and a bigger bang for your buck. Really knows his stuff. Little things in addition to the duration and lift, but also addressing lobe separation and making sure you have a cam that just doesn't produce power at high RPM's, unless that's what you want.

Heads. A new set of Aluminum, quality heads, changing springs to have the right ones for your roller cam, are going to be in the $1400 neighborhood by the time you are finished. The best two choices based on my research, in terms of flow numbers and HP produced not just at high RPM's but "under the curve", from .10 - .50 lift, are the AFR 165's and the Trick Flow Twisted Wedge heads.

AFR's are cast in the USA, and are extremely popular. Heads are around $1250 - $1275, plus new springs for the roller, takes you up to $1400. I was going with AFR's until Unique told me I would have to modify my exhaust header / manifold in order to use them. They recommended Trick Flow or Edelbrock. Several other head distributors / engine builders recommended Trick Flow, or AFR, and all the flow numbers pointed to these as the top two, basically with the same CFM numbers.

Since I thought I'd have a problem with the AFR's I went with Trick Flow Twisted Wedge heads from Panhandle Performance, their Stage I package. They buy the casting, polish the bowl, use higher quality valves than the stock ones (Ferrea Racing Valves) and do a competition valve job, plus use the upgrade springs for the roller cam. Just got them, and they are beautiful.

The big issue is balance, from everyone I've spoken to.

-302 block 1987
-forged pistons
-new cam, 221 duration @ .050; .500 / .500 lift; 10 deg lobe
separation
-TF Twisted Wedge Heads flow 254 / 193 (intake / exh)
at .500 lift
-Edelbrock RPM Performer intake manifold
-Comp Cams pro magnum roller rockers
-Speed Demon 575 carb
-Projected HP 350 at 5800 RPM

Careful with the intake manifolds. Volume of CFM must be balanced with Velocity. More velocity is important so that the vaporized fuel / air mixture moves quickly into the cylinder. Don told me to stay away from the Air Gap intake manifold on the little 302 motor, too much volume and not enough flow. Does not work well at lower RPM's. Has to get up to 3000 RPM to run better.

But again, these are opinions, but at least opinions of people who have built race cars and motors for 35 years or more.

You should be able to get to around 400 HP and still have a car that can be driven on the street. Have fun with your research, I have had a ball with mine, and know a lot more about motors today than I did 3 months ago!!

Rick

[blykins]

Some very good points indeed, Rick...especially the point about the capability (or lack thereof) of a small displacement engine to suck in the volumetric amount of air that an intake can provide.

However, *most* guys who build engines for these cars are not building just putt-around-the-street engines...they're building performance engines....with higher duration and lift cams that push the powerbands up into the rpm range....3000 rpms is nothing for a small block and most engines don't have powerband peaks until the high 5 or 6k range. So to stay away from the RPM intake because it doesn't make power way down low doesn't make much sense to me....To take advantage of a high performance cylinder head such as an AFR or TrickFlow, you need a high performance cam anyway....which would necessitate a high performance intake manifold.

My opinion isn't worth much in a forum full of engine builders and drag racers....but it seems like if you want to make 400 hp out of a small cube engine and make it at a peak of 6000-6500....you wouldn't be worried about what you could do below 3000 revs.

[JustOne]

Blykins,
According to my numbers from the chart, link on page one, the GT 40X heads flow 214int and 149 exh. Can you run those numbers through your desktop dyno, my PC with the program on it has crashed. Also, can you run my Avenger Heads through it?
The Avenger head flows 327 int and 247 exh. The cam is 246int /254 exh and .622/ 637 lift at 50 with 112 degree loab speration. This is a hydraulic roller. Also, I find that if you pick the dynomax ultraflow mufflers and 3 1/2 exhaust in Dyno 2000 we get closer to the real flywheel horsspower.

[JustOne]

Sorry, cam is 254int / 264 exhaust and the motor is a 425ci windsor with 11.25:1 comp.
And I forgot to mention that I had the GT 40X fully ported heads on a Mustang and switched to the TFS twisted wedge stock head and the car picked up 3 tenths. This was with a stock 93 bottom end a Cobra GT 40 intake and an E303 camshaft.

[blykins]

Sure thing....

What's the rest of your specs?

Also, does that link have the Avenger heads on it? Desktop Dyno requires more than 1 intake/exhaust set.....and of course the more you input the more accurate it is....I usually try to input 5 sets of data...

So what brand of roller cam is that? I haven't seen many hydraulic rollers with that high lift....

I have Desktop Dyno 2000...but I don't think mine will allow different brands of exhaust.....Usually I try to nail the size of headers and tell the program that it's running through mufflers....I feel that combo gets pretty close for me...