302 or 351?
 

Hey guy's I am still in the planing stages of my build. Question 302 or 351? I have A big block 429 but have pretty much ruled out the big block as to expensive to build and drive plus insurance has said no to my plans for an occasional trip to the drag strip so... I have decided to go small block. Are you guy's with the 302s happy with your decision? Or do you wish you had gone with the 351.

Also how about fuel economy with the 351? 302?

thanks Kevin

Kevin; you are planning a "Cobra," right? Not a Miata?




:LOL: Sorry man, with all the talk about no BB, fuel economy, etc I had to yank your chain a little. ;)

Steve

You'll get more horsepower easier with the 351W or 351W Stroker than the 302's and they will handle the horsepower better. Weight difference is minor and available options for both is about equal.

Bob

thanks for the replies Steve I WOULD LOVE TO PUT MY 429 in when I start my build, but I live in the hills lots of curves you know the family that heads to the lake once A year and you meet them in A corner halfway in your lane! My friends pointed this out to me as well as hauling the big block around all these corners. I still would like lots of tourqe with out all the weight:D

ps miata really :LOL: Kevin

Bob I noticed you have A 351 stroker? Is it easy to live with? what I mean is how well does the car handle in corners,and what about economy? I know I know economy! but the budget kinda requires it!:D

thanks Kevin

Go with the 351 as you can make a lot more power ie stroke it to 427 and you have a small block with big cubes and power. You won't be sorry!

If you're not trying to adhere to the "rules" of originality, then go with a Windsor or stroked Windsor. You can go out to 425ci with a factory Windsor block pretty easily.

The more cubes you have, the easier it is to make horsepower without having to add high compression ratios, huge cams, etc.

Economy? Unleaded @ $3.10 Premium $3.50 = $6.40 per fill up if totally empty. Say you fill up once a month, $76.80 a year.
How much money are you spending on this thing?
If gas mileage is a consideration I would have to assume that you do not intend standing on it in first or second gear. Let alone over 60mph.
Build what you want and drive the **** out of it when you want to, and if you need to save money drive slowly somewhere park it and enjoy the view.

If you're building on a budget, which it sounds like you are (as I did, as well), you get very good bang for your buck out of a 302 standard stroke. Cobras are light, and a 302 with standard stroke will give you plenty of giddyup. If you are planning on buying your engine from a builder, you can get a VERY nice, complete 302 for under $9k. For a 351W, if I recall correctly you'll be upwards toward $12k+. More for a 351W stroker.

Ford Racing has some nice 302 long block assemblies for $4k from Summit Racing. Keith Craft does some impressive strokers for a little under $9k (if I recall correctly). KC's is putting out 425 hp? Yeah, that'll do the trick.

You can have a lot of (economical) fun with a pumped up 302.

DD

I bought a used 1969 351w for my cobra. It was pulled form a 32 Ford Street Rod. Paid $490 for it. The guy said it was rebuilt with only 3000 miles on it. No proof of anything. Only thing I did to it was a little cleaning and changed the plugs and wires. I can still get the tires to spin at 55 mph. Only time I checked mpg I got 18. There are deals out there, just keep looking. I was about a year into my build before I bought the engine. In a 302 max hp is about 400. A 351w 400 hp is easy. Go with the bigger motor !!!!! Jim

You gotta cobra man, who cares about fuel efficency, drive it like a nanna, or go hard, your choice---Mic

Always take the increased deck height.

Bob

Other than the approx 1" deck height difference, are the external mounts the same on late model 302's and 351's?
I know that the intake and balance is different, but I am considering going with a 351 instead of a 302 which is in the car. Header changes because of deck height, and what else will be a headache?

A mildly stroked 351 would be a more than sufficient powerplant with tons of low end torque, and well into the 400 hp range with similar torque. Probably 450/450 range. Keith Craft could build a nice one for you. I went with a stroked 302 = 331 stroker from KC. 446 flywheel hp at 6000 rpm, and 326 to the rear wheels. Torque range is a little higher than what you would have in the 351. Can't go wrong either way. I had a stock 302 HO motor in my first cobra. Roughly 300 hp, with a low lift cam, and low end torque. Car was very quick accelerating, LOT of low end torque - on a 1.6 mile track with 8 curves cars with over 500 hp couldn't "out accelerate" me. Tweaked that motor - new high flow heads and higher lift cam. Increased HP by 75 - 80, but lost the low end torque, and it was not as quick to accelerate.

HP alone doesn't mean a lot. When do you have it and where is your torque. Generally speaking I believe, even though I love my 331, that a 351 will be a better all around performer on the street and the track primarily due to having more low end torque.

What would be the weight diffference between an fe engine w/ alum heads, intake an a 351 with the same?

I had a 351 Windsor stroked to 418 in my Cobra and it put out around 530 horse and 520 pound torque. Much easier to drive than my big block and I had more than enough power when on a track. A friend of mine has a 302 that is mildly upgraded and it is a really nice car to drive and has good performance, but nothing like the 351 strokers have. If you are going to be racing or running fast around curves, I would go with the 351 stroker. A friend of mine had a 429 in his and he couldn't begin to keep up with me on the track or curvy roads. But I am sure that in a drag race he would have beat me. I have always road raced and just prefer the smaller blocks.

Marvin,

What would be the weight difference between an Fe engine w/ alum heads, intake an a 351 with the same?

It would still be about the same as with iron heads. You would gain a small amount because of the size of the big block FE heads. I had everything but an aluminum block on my stroker but I don't remember what it weighed.

Ron :)

When you'rre talking about a 302W based engine vs. a 351W based engine, you'll find that the cost differance is rather small. Once you "step up" to a Lima or FE motor, costs are significantly higher. The advantage to the FE motor is that it's historic. It looks good, and it looks right. Same thing with the magical 427 cubes, it just feels right. If that's what you have to have, then build it right to begin with.

The advantage of the 460 motor is... well... ummm... hang on, it will come to me. ;)

This is my second Cobra build. The first one was not exactly built on a budget, but I did decide to be "reasonable" and used a moderate build 302 with a carb. It was a fun car, made good power, and was reasonable to build. Not too expenive, not too complicated.

But, I quickly realized that it wasn't enough. Within a few months, I was planning power upgrades. It soon got to the point where it was either tear it apart and rebuild it. Or sell it and start over. Fortunatly, I decided to sell and build another one. I ended up with a much better car the second time around.

The point is, don't be reasonable. This is your dream car. Build what you want the first time around. If you want a 600hp car, then build one. If it has to have 427 cubes, or 550hp, or an FE motor, then build it. Don't scimp - you won't be happy. Dream big, build big.

Thanks for the replies! looks like A 351 or 351 windsor stroker build is in my future! I have A 429 but not married to it! Thanks Bob for sharing your wisdom and experience that's why I joined this forum was to learn from others who have been there and done that. Thanks everyone for your input looks like its off to the bone yard for A 351.:D


Kevin

coupe shots
 

Hi Kevin, sounds like you are going to go ahead and put the 351 in the car, did I ever get you these shots of my finished Coupe, I put the 351 In my car and love it.