The Ford Barn

Craig CT · 07-08-2022, 10:01 PM

Hello all; A friend of mine is building a fiberglass Cobra kit car. He has 373 rear gears, will use a 5 speed manual transmission, and a 302 ford engine with a four barrel carburetor and distributor ignition. He's looking for a cam recommendation to get a little more performance from the 302. Maybe a 3/4 hydraulic. Thanks in advance for any suggestions, Craig.

Alaska Jim · 07-09-2022, 12:03 AM

Back in the mid 70's I used a Sig Erson hi-flo 1 cam with good results, but I don't know if they are even in business anymore. sorry I can't help more. haven't played with a small block ford for a long time

KULTULZ · 07-09-2022, 01:17 AM

Quote:

A friend of mine is building a fiberglass Cobra kit car. He has 373 rear gears, will use a 5 speed manual transmission, and a 302 ford engine with a four barrel carburetor and distributor ignition. He's looking for a cam recommendation to get a little more performance from the 302.

302 or 5.0L?

IMO, the easiest way out of this is to speak with a minimum of three cam manufacturers TECH LINE as to the best solution.

They will need to know how the car will be used, engine specs, trans type, rear, wheel size and tire diameter.

IMO - You will want a roller unless it will be full competition.

rotorwrench · 07-09-2022, 08:23 AM

Cams start out in the stock range which gives good horse power AND torque range. As the performance level changes, there is a trade off between horse power and low end torque. The more lift the more horse power but the torque curve changes a lot so it boils down to how a person wants it to perform. For all out high speed a person goes toward high lift & high duration. For street use with the crap gas we have in this day and age then a person should go with a cam that gives best overall performance on the street between low end torque and top end speed. Most cam manufacturers explain their cams fairly well as to what the different grinds will do for the end user. If they don't, then look for another source.

I've never figured why folks still use the 3/4 lift term. 3/4 of what is the question. It's a lot more scientific now days so those old 40s terms don't really fit. This link may help some.
https://www.diyford.com/small-block-...ing-camshafts/

Performance cams also require spring pressure changes and selection of different lifters depending on application. There is a lot to learn when stepping up the performance levels.

marko39 · 07-09-2022, 08:38 AM

Quote:

Originally Posted by rotorwrench

Cams start out in the stock range which gives good horse power AND torque range. As the performance level changes, there is a trade off between horse power and low end torque. The more lift the more horse power but the torque curve changes a lot so it boils down to how a person wants it to perform. For all out high speed a person goes toward high lift & high duration. For street use with the crap gas we have in this day and age then a person should go with a cam that gives best overall performance on the street between low end torque and top end speed. Most cam manufacturers explain their cams fairly well as to what the different grinds will do for the end user. If they don't, then look for another source.

I've never figured why folks still use the 3/4 lift term. 3/4 of what is the question. It's a lot more scientific now days so those old 40s terms don't really fit. this link may help some.
https://www.diyford.com/small-block-...ing-camshafts/

Performance cams also require spring pressure changes and selection of different lifters depending on application. There is a lot to learn when stepping up the performance levels.

I always thought a 3/4 cam ment 3/4 race versus a full race cam.

KULTULZ · 07-09-2022, 09:15 AM

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Quote:

Originally Posted by marko39

I always thought a 3/4 cam ment 3/4 race versus a full race cam.

That was a term used post WWII and fifties.

55blacktie · 07-09-2022, 10:51 AM

It's cam duration, not lift, that's primarily responsible for moving torque and horsepower up the rpm range. When discussing big/small cams, it's a reference to duration, not lift. If the replacement cam has significantly more lift, make sure that the valve springs are compatible.

miker98038 · 07-09-2022, 07:57 PM

And valve to piston interference. Makes a lot of noise (briefly) if they hit. I don’t have any experience with modern sbf’s, but the keeper to valve guides can also be a problem with higher lifts.

55blacktie · 07-09-2022, 11:57 PM

Good point, Miker. He should be ok with valve lift below .500, but he needs to verify.

LOWRIDER · 07-10-2022, 06:09 AM

I've read many posts on numerous sites where "younger" guys question the term 3/4 cam. Like it's been mentioned it was just a term we used to describe a cam back then. To me it's no dumber than installing a RV cam a name used today. What, your gonna install a RV cam then take it camping.

56sedandelivery · 07-10-2022, 08:29 AM

Quote:

Originally Posted by KULTULZ

That was a term used post WWII and fifties.

And 60s. Don’t ask how I know.

KULTULZ · 07-10-2022, 08:55 AM

Quote:

Originally Posted by 56sedandelivery

And 60s. Don’t ask how I know.

Yeah, 3/4 was describing between stock and full race.

I remember ...

... when RV cams came out. It was when gasoline was de-rated (lead) and they were used mainly to allow increased performance (CR) on cheap gas.

As mentioned, RV to me refers to a LT engine.

BTW- How is the '56 coming along?

rotorwrench · 07-10-2022, 12:01 PM

The one cam manufacturer that always makes me scratch my head is Comp Cams. They start out as HV series then they go to classic thumpr. From there they go to mutha thumpr and then on to the big mutha thumpr. If all a person cares about is how much their engine thumps then they can buy a Comp Cam product.

If a person want to really know what a particular cam grind will do for you then a person needs to look at the product catalogs for the different manufacturers. Their descriptions mention compression ratios usable with and carburetor CFM recommendations and the like. There are a lot of listings for the Ford 302 in Isky and Crane listings.

A person has to settle on which series of 302 to use as well. They changed to roller engines in the later years and that makes a difference. Later ones were set up for fuel injection. Older engines were carbureted but some have smog dog heads. What type of carburetor or fuel injection to use, what type of exhaust to use, how much compression to run and what type of fuel do you want to buy for this project car. If money is no object then a person can have an engine built for them per the builders recommendations.

My own conclusions would be to do the research and checking on line and then make an informed decision where to go from there. A lot of forums deal with Ford cars, trucks, 4X4s, and all will give a different recommendation about what to use. I'll pretty much guarantee that you won't find a listing that states"good 3/4 race cam for 302".

5851a · 07-10-2022, 03:40 PM

https://customfordcams.com/products Not making a recommendation but seems to have a list of questions covering the things.

KULTULZ · 07-10-2022, 06:13 PM

Quote:

Originally Posted by 5851a

https://customfordcams.com/products Not making a recommendation but seems to have a list of questions covering the things.

DAMN! A camshaft consultant and middle man ...

miker98038 · 07-12-2022, 02:42 PM

He’s sure asking the right questions and making the right remarks. If he’s got the data base and engineering knowledge to support it he’d be a great resource.

07-08-2022, 10:01 PM	#1
Craig CT Senior Member Join Date: May 2010 Location: Sherman, CT Posts: 330	cam question Hello all; A friend of mine is building a fiberglass Cobra kit car. He has 373 rear gears, will use a 5 speed manual transmission, and a 302 ford engine with a four barrel carburetor and distributor ignition. He's looking for a cam recommendation to get a little more performance from the 302. Maybe a 3/4 hydraulic. Thanks in advance for any suggestions, Craig. __________________ " When I was a boy of fourteen, my father was so ignorant I could hardly stand to have the old man around. But when I got to be twenty-one, I was astonished at how much he had learned " Mark Twain.

07-09-2022, 12:03 AM	#2
Alaska Jim Senior Member Join Date: May 2010 Location: Palmer, Alaska Posts: 1,575	Re: cam question Back in the mid 70's I used a Sig Erson hi-flo 1 cam with good results, but I don't know if they are even in business anymore. sorry I can't help more. haven't played with a small block ford for a long time

07-09-2022, 08:23 AM	#4
rotorwrench Senior Member Join Date: Jun 2010 Location: San Antonio, Texas Posts: 16,432	Re: cam question Cams start out in the stock range which gives good horse power AND torque range. As the performance level changes, there is a trade off between horse power and low end torque. The more lift the more horse power but the torque curve changes a lot so it boils down to how a person wants it to perform. For all out high speed a person goes toward high lift & high duration. For street use with the crap gas we have in this day and age then a person should go with a cam that gives best overall performance on the street between low end torque and top end speed. Most cam manufacturers explain their cams fairly well as to what the different grinds will do for the end user. If they don't, then look for another source. I've never figured why folks still use the 3/4 lift term. 3/4 of what is the question. It's a lot more scientific now days so those old 40s terms don't really fit. This link may help some. https://www.diyford.com/small-block-...ing-camshafts/ Performance cams also require spring pressure changes and selection of different lifters depending on application. There is a lot to learn when stepping up the performance levels. Last edited by rotorwrench; 07-09-2022 at 08:37 AM.

07-09-2022, 10:51 AM	#7
55blacktie Senior Member Join Date: Aug 2020 Posts: 442	Re: cam question It's cam duration, not lift, that's primarily responsible for moving torque and horsepower up the rpm range. When discussing big/small cams, it's a reference to duration, not lift. If the replacement cam has significantly more lift, make sure that the valve springs are compatible.

07-09-2022, 07:57 PM	#8
miker98038 Senior Member Join Date: Mar 2013 Location: Kent, WA. Tucson, AZ Posts: 1,397	Re: cam question And valve to piston interference. Makes a lot of noise (briefly) if they hit. I don’t have any experience with modern sbf’s, but the keeper to valve guides can also be a problem with higher lifts.

07-09-2022, 11:57 PM	#9
55blacktie Senior Member Join Date: Aug 2020 Posts: 442	Re: cam question Good point, Miker. He should be ok with valve lift below .500, but he needs to verify.

07-10-2022, 06:09 AM	#10
LOWRIDER Senior Member Join Date: May 2010 Location: Kingman Az. 86409 Posts: 419	Re: cam question I've read many posts on numerous sites where "younger" guys question the term 3/4 cam. Like it's been mentioned it was just a term we used to describe a cam back then. To me it's no dumber than installing a RV cam a name used today. What, your gonna install a RV cam then take it camping. __________________ Dan Kingman Az. 86409

07-10-2022, 12:01 PM	#13
rotorwrench Senior Member Join Date: Jun 2010 Location: San Antonio, Texas Posts: 16,432	Re: cam question The one cam manufacturer that always makes me scratch my head is Comp Cams. They start out as HV series then they go to classic thumpr. From there they go to mutha thumpr and then on to the big mutha thumpr. If all a person cares about is how much their engine thumps then they can buy a Comp Cam product. If a person want to really know what a particular cam grind will do for you then a person needs to look at the product catalogs for the different manufacturers. Their descriptions mention compression ratios usable with and carburetor CFM recommendations and the like. There are a lot of listings for the Ford 302 in Isky and Crane listings. A person has to settle on which series of 302 to use as well. They changed to roller engines in the later years and that makes a difference. Later ones were set up for fuel injection. Older engines were carbureted but some have smog dog heads. What type of carburetor or fuel injection to use, what type of exhaust to use, how much compression to run and what type of fuel do you want to buy for this project car. If money is no object then a person can have an engine built for them per the builders recommendations. My own conclusions would be to do the research and checking on line and then make an informed decision where to go from there. A lot of forums deal with Ford cars, trucks, 4X4s, and all will give a different recommendation about what to use. I'll pretty much guarantee that you won't find a listing that states"good 3/4 race cam for 302".

07-10-2022, 03:40 PM	#14
5851a Senior Member Join Date: Oct 2014 Location: NE Iowa Posts: 1,664	Re: cam question https://customfordcams.com/products Not making a recommendation but seems to have a list of questions covering the things.

07-12-2022, 02:42 PM	#16
miker98038 Senior Member Join Date: Mar 2013 Location: Kent, WA. Tucson, AZ Posts: 1,397	Re: cam question He’s sure asking the right questions and making the right remarks. If he’s got the data base and engineering knowledge to support it he’d be a great resource.