[tom991]

Have the shop put in larger intake valves. I had 1.94" intake valves put in my heads when I had it machined and it really makes a difference along with porting by improving the engines breathing better. I have C4OE casting heads with even smaller CCs. My CR calculations show 9.5:1 with Speedpro FT pistons with 4 valve reliefs per piston, block is bored .040 over. You could get 2 valve relief pistons.

I bought my cam as a kit that included the cam, valve springs and lifters. It's a Crane Energizer 130032. I spoke to the Crane tech representative and told him what I wanted to achieve and what I had. He recommended the cam, kit with lifters and valve springs. So that's what I bought and am happy with it. The fuel pump eccentric/timing sprocket dowel it came with was too short so I had to get a different one.

 

[zray]

I put the 1.94/1.60 valves (Ferrea) in my last K code. I did Like the mid range to high rpm performance, but there was a low rpm drop off in torque. Bigger valves are a trade off. Ford went too large in the '69 Boss 302. I believe they reduced valve size in the '70 model. If you go too large, air velocity suffers until the rpm catches up.

Z

 

[tom991]

I put the 1.94/1.60 valves (Ferrea) in my last K code. I did Like the mid range to high rpm performance, but there was a low rpm drop off in torque. Bigger valves are a trade off. Ford went too large in the '69 Boss 302. I believe they reduced valve size in the '70 model. If you go too large, air velocity suffers until the rpm catches up.

Z

I don't notice any low end decrease in torque. The carb, Autolite 4100, Intake Performer 289, and Crane cam that I have gives me great throttle response and the ability to easily break the tires loose. I don't drive like that but they will break loose if I give her too much throttle by mistake or come off the clutch too fast.

 

[atitagain]

Thanks atitagain for the explanation. If I'm thinking correctly (advise if not), if the CR is lower, say 9.25 - 9.5:1, what effect on horsepower will this have (obviously lower but to what extent, all else equal)?

Also, is this why the head machine shop was asking about what cam I'm going to use? So he could make sure the dynamic compression is acceptable for pump gas?

Thanks,

Allen

Allen,

as other have said, a decrease in static CR isn't a huge difference in HP. There is a rough math formula I just don't remember it right now...it's less than 10 HP i can tell you that. More important is dynamic and making sure you can live with 91 octane without retarding the timing and effect performance.

the machine shop is asking cam specs to ensure the use the proper springs.

Forgot, auto or manual?

Since you have screw in studs you can use a newer profile cam with more lift, less duration that typical older grind cams....Or the Hipo. I would have the shop port the exhaust for sure!!!

22GT has a combo with hipo cam, 600 CFM carb, ported exhaust manifold and 320 HP result on the dyno...

again with screw in studs, you can use more lift (modern grind) and less duration to suit your needs

 

[6sally6]

OK..........its not gonna be a drag/race car just a fun street rod/cruiser, right?!
IF you go with the 10:1 cr you need a pretty lumpy cam to bleed off some of the compression at low(er) speeds where detonation can be an issue.
You have a manual tranny so low vacuum issues are a....non-issue!
Since its a "fun piece" don't sweat the parts about "too much duration/too much lift/not enough lift or duration or whatever."
In a race situation those heads will choke off big HP anyway so discount that too.
220/225* duration intake about the same for exhaust duration..maybe 5* more because of the mufflers. 110* LSA will probably bleed it off enough for premium fuel. I would go 108*LSA and get that dirt track engine idle.
HEY!! its gonna be a "cruiser special"..right?!
It will still have decent low end torque even with the 3.00:1 gear. Have the cam advanced some(4/6*) and get more low end back!
Now it WILL be "peaky"....meaning great acceleration above 1500rpm and be over with by 6000rpm. HEY.......what's wrong with that!!
You ain't racing it....just enjoy the experience.
6sally6

 

[atitagain]

OK..........its not gonna be a drag/race car just a fun street rod/cruiser, right?!
IF you go with the 10:1 cr you need a pretty lumpy cam to bleed off some of the compression at low(er) speeds where detonation can be an issue.
You have a manual tranny so low vacuum issues are a....non-issue!
Since its a "fun piece" don't sweat the parts about "too much duration/too much lift/not enough lift or duration or whatever."
In a race situation those heads will choke off big HP anyway so discount that too.
220/225* duration intake about the same for exhaust duration..maybe 5* more because of the mufflers. 110* LSA will probably bleed it off enough for premium fuel. I would go 108*LSA and get that dirt track engine idle.
HEY!! its gonna be a "cruiser special"..right?!
It will still have decent low end torque even with the 3.00:1 gear. Have the cam advanced some(4/6*) and get more low end back!
Now it WILL be "peaky"....meaning great acceleration above 1500rpm and be over with by 6000rpm. HEY.......what's wrong with that!!
You ain't racing it....just enjoy the experience.
6sally6

6sally6

i am no cam expert but isn't a 220 duration a bit big for just a "stock" with a little more power? esp in a 289 for 100% street? I was thinking one size down from that for his intended use

 

[Turnall]

OK..........its not gonna be a drag/race car just a fun street rod/cruiser, right?!
IF you go with the 10:1 cr you need a pretty lumpy cam to bleed off some of the compression at low(er) speeds where detonation can be an issue.
You have a manual tranny so low vacuum issues are a....non-issue!
Now it WILL be "peaky"....meaning great acceleration above 1500rpm and be over with by 6000rpm. HEY.......what's wrong with that!!
You ain't racing it....just enjoy the experience.
6sally6

6sally6, in the third post I answered Paul that I have an auto transmission...it's not going to change. Does this change your assessment since it is an automatic? Thanks,

Allen

 

[zray]

It bears pointing out that the 289 HiPo has 10.0:1 compression, and it runs on modern 91 or 93 octane fuel with no problems whatsoever. Over the past 20+ years I've had several GT350's and K codes that use this engine, probably have driven a cumitative 150,000 miles in those cars. Never any detonation, ever. And that's with the stock timing of 40 degrees BTDC. Oops ! I forgot when I've had a vintage Paxton supercharger installed on those "high compression" engines.

Point is, I've overhauled numerous HiPo engines and had a verified 10.0:1 compression on every one of them. These old 10.0:1 iron head engines, together with a HiPo type cam will not give you any issues on readily available pump gas. Plenty of power, no lumpy idle, and very reliable.

Z

PS. I did lower the timing to 38 degrees BTDC on these engnes wheni had a vintage Paxton supercharger. Not much of an adjustment.

 

[Fastback97]

Fastback97, it is the stock 3.00 gears to my knowledge...

I have an auto transmission...it's not going to change.
Allen

I'd definitely go with a comp cams XE256H (212/218 @.050) unless you just plan on driving mainly on the highway and are willing to sacrifice low-end drivability.

 

[HoosierBuddy]

I ran one of the comp xe cams on my 289 with AFR heads and was very impressed with it. My suggestion is you are going about this all wrong. Simply call the Comp Cams tech line, tell them your whole setup and ask them what cam to buy. Or, call a couple of cam manufacturers. They have about 1000 times more experience than any of us will have.

Phil

 

[atitagain]

It bears pointing out that the 289 HiPo has 10.0:1 compression, and it runs on modern 91 or 93 octane fuel with no problems whatsoever. Over the past 20+ years I've had several GT350's and K codes that use this engine, probably have driven a cumitative 150,000 miles in those cars. Never any detonation, ever. And that's with the stock timing of 40 degrees BTDC. Oops ! I forgot when I've had a vintage Paxton supercharger installed on those "high compression" engines.

Point is, I've overhauled numerous HiPo engines and had a verified 10.0:1 compression on every one of them. These old 10.0:1 iron head engines, together with a HiPo type cam will not give you any issues on readily available pump gas. Plenty of power, no lumpy idle, and very reliable.

Z

PS. I did lower the timing to 38 degrees BTDC on these engnes wheni had a vintage Paxton supercharger. Not much of an adjustment.

Won't argue with any of that. The dynamic compression ratio of hipo is around 8.2:1, the smaller cams would be 8.57:1 and above. I am assuming the hipo's cam's intake ABDC is around 61

 

[Turnall]

It bears pointing out that the 289 HiPo has 10.0:1 compression, and it runs on modern 91 or 93 octane fuel with no problems whatsoever. Over the past 20+ years I've had several GT350's and K codes that use this engine, probably have driven a cumitative 150,000 miles in those cars. Never any detonation, ever. And that's with the stock timing of 40 degrees BTDC. Oops ! I forgot when I've had a vintage Paxton supercharger installed on those "high compression" engines.

Point is, I've overhauled numerous HiPo engines and had a verified 10.0:1 compression on every one of them. These old 10.0:1 iron head engines, together with a HiPo type cam will not give you any issues on readily available pump gas. Plenty of power, no lumpy idle, and very reliable.

Z

PS. I did lower the timing to 38 degrees BTDC on these engnes wheni had a vintage Paxton supercharger. Not much of an adjustment.

Is this the C9OZ-6250-C camshaft that 22GT has had in some of his other responses? Really not looking for this to be complicated...:grin2:

Allen

 

[LSG]

289

AllenTurn, do you know what pistons the shop with the block plans on using ? 'flattops' is an insufficient answer. Some flattops are 1.585 tall and some are 1.605 tall. The chart you showed a few posts back leads me to think they have the wrong ones, .039 is way, WAY too far down in the hole. Too wide of a quench distance and you're more likely to detonate. Whats the part number ?

On the heads...what valve sizes are you going to run ? And you're putting hard seats under the exhausts, right ?

Are you keeping the three speed auto ?

LSG

 

[Fastback97]

Is this the C9OZ-6250-C camshaft that 22GT has had in some of his other responses? Really not looking for this to be complicated...:grin2:

Allen

These are the Howard Cams specs for the C9OZ-6250-C:
Cam Style: Hydraulic flat tappet
Basic Operating RPM Range: 1,600-5,200
Intake Duration at 050 inch Lift: 218
Exhaust Duration at 050 inch Lift: 218
Duration at 050 inch Lift: 218 int./218 exh.
Advertised Intake Duration: 288
Advertised Exhaust Duration: 288
Advertised Duration: 288 int./288 exh.
Intake Valve Lift with Factory Rocker Arm Ratio: 0.460 in.
Exhaust Valve Lift with Factory Rocker Arm Ratio: 0.460 in.
Valve Lift with Factory Rocker Arm Ratio: 0.460 int./0.460 exh.
Lobe Separation (degrees): 113

If you want 47 year old cam technology with a narrower useable power band compared to a modern split duration, that cam is for you!

 

[Turnall]

AllenTurn, do you know what pistons the shop with the block plans on using ? 'flattops' is an insufficient answer. Some flattops are 1.585 tall and some are 1.605 tall. The chart you showed a few posts back leads me to think they have the wrong ones, .039 is way, WAY too far down in the hole. Too wide of a quench distance and you're more likely to detonate. Whats the part number ?

On the heads...what valve sizes are you going to run ? And you're putting hard seats under the exhausts, right ?

Are you keeping the three speed auto ?

LSG

LSG, the chart is just numbers I put in trying to learn how the calculator works and has nothing to do with the shop (I will be buying the pistons and doing the assembly). Yes on the hardened seats and yes on the 3 speed auto. On the valve sizes, I'm not sure yet. Gathering this information to talk to the "head" shop about.

Allen

 

[Turnall]

These are the Howard Cams specs for the C9OZ-6250-C:
Cam Style: Hydraulic flat tappet
Basic Operating RPM Range: 1,600-5,200
Intake Duration at 050 inch Lift: 218
Exhaust Duration at 050 inch Lift: 218
Duration at 050 inch Lift: 218 int./218 exh.
Advertised Intake Duration: 288
Advertised Exhaust Duration: 288
Advertised Duration: 288 int./288 exh.
Intake Valve Lift with Factory Rocker Arm Ratio: 0.460 in.
Exhaust Valve Lift with Factory Rocker Arm Ratio: 0.460 in.
Valve Lift with Factory Rocker Arm Ratio: 0.460 int./0.460 exh.
Lobe Separation (degrees): 113

If you want 47 year old cam technology with a narrower useable power band compared to a modern split duration, that cam is for you!

Thanks Fastback. I wouldn't know the difference between 47 year old cam technology and 47 minute old cam technology. It's not what I do, so I have ask for suggestions and I'm trying to learn and understand as much as I can about it to make the correct decision for what I want from this vehicle. I have taken your suggestion into consideration and will talk to my guys about it. The cam that 22GT had suggested in another post (with other things) painted a simple picture of getting close to 270 or so hp from the engine I'm putting in this car, which I think will be plenty for how I'm going to use it. If there is a better cam and I can use some other parts internally to make it more reliable, more hp and more efficient, I'm all for it. I've tried to explain what I want to the best of my knowledge and trying to answer all the questions so that answers back can be given informatively.

If I knew what cam it needed/wanted, I would have told the head shop and never asked here...

Allen

 

[66kcar]

22GT, LSG and zray are (among other) folks I would rely on here at this site. I have not built a 289 with a flat tappet cam in 20 years, so I will stay out of the specific recommendations.


I will say that lift of .460 - .480 and advertised duration of 205 - 225 will work very well with 9.25 - 10.0 compression. You should be at 275 - 320 FWHP with ported heads and the 4 barrel carb. Don't forget some headers (whole other can of worms). The 3.0 gears are holding you back. Try some 3.50 - 3.89 since it is a fun cruiser and not a gas mileage worry.


Keep near those guidelines and you will have a fun, peppy car. Don't sweat 10 or 15hp here or there - let the internet dyno guys carry on about that!

 

[Fastback97]

Going with 22GT's suggestion would be fun, just don't expect the same useable power band as a modern split duration.

 

[Turnall]

Going with 22GT's suggestion would be fun, just don't expect the same useable power band as a modern split duration.

Does split duration simply mean that the intake and exhaust duration are different?

Allen

 

[Woodchuck]

Thanks Fastback. I wouldn't know the difference between 47 year old cam technology and 47 minute old cam technology. It's not what I do, so I have ask for suggestions and I'm trying to learn and understand as much as I can about it to make the correct decision for what I want from this vehicle. I have taken your suggestion into consideration and will talk to my guys about it. The cam that 22GT had suggested in another post (with other things) painted a simple picture of getting close to 270 or so hp from the engine I'm putting in this car, which I think will be plenty for how I'm going to use it. If there is a better cam and I can use some other parts internally to make it more reliable, more hp and more efficient, I'm all for it. I've tried to explain what I want to the best of my knowledge and trying to answer all the questions so that answers back can be given informatively.

If I knew what cam it needed/wanted, I would have told the head shop and never asked here...

Allen

The four-stroke engine has been around since about 1876. Heck, Ford has an all-aluminum 32-valve double-overhead cam V8 engine in 1940. Modern technology? Here's Ron Iskendarian's take on split pattern cams....

Tech Tips 2000? - Isky Racing Cams

There's nothing wrong with the C9OZ-6250-C and Howard's is NOT a "near exact replica" of it, either. You might want to call these guys... Cam Grinding, Camshafts, Racing & Performance Equipment