302 vs. 351 empty block weights

Pete Munroe · #1 (**permalink**) 03-06-2003, 11:56 AM

Gang,

Along the lines of an earlier thread "why bother" on a $$$ stroked 302 vs. a 351 based on weights and, maybe c.g., here are some numbers from the 99' SVO catalogue.

Guess it comes down to what your priorites are for your car, handling vs. acceleration, and pocket book...

Some bare block weights;

5.0 liter HO/302 production - (very similar to early 289?)
deck hgt - 8.206, journal dia - 2.248, weight - 135 lbs~

SVO 302 Race - (available in 8.7 deck height...more weight)
deck hgt - 8.200, journal dia - 2.248, weight - 160 lbs~

351 SVO Sportman block
deck hgt - 9.500, journal dia - 3.00, weight - 200lbs~

(no prother 351 variants, 190 to 205 lbs~

460 SVO variants
deck hgt - 9 to 10.3, journal dia 3.00, weight 260 to 290 lbs~

Aluminum blocks:

SVO 302 aluminum 97 lbs~

SVO 351 aluminum, wet or dry sump 127 to 137 lbs~

Coudn't find aluminum vs. iron heads, water pumps, or intake manifolds.

The 3.00 journal 351 crank has to weigh a little more than a 2.248 journal crank.

All in all, maybe a 100 lb difference bewteen the basic
289-302 vs. 351's after all.

Another way to look at it, a 90 lb. bag of cement on the front end of the car.

Pete

hound dog · #2 (**permalink**) 03-06-2003, 01:19 PM

Good info, Pete. Thanks.
h dog

FIA#9 · #3 (**permalink**) 03-09-2003, 07:36 AM

What a fantastic web site. Great info guys--the weight is very important. The last post was exactly on point. If you replace an iron headed 302 with an Al headed 351, the net change is minimal. I've got a quote written in the front of a folder full of Cobra info (source unknown now): "Truely hot 289 competition Cobra had a power to weight ratio of 5.75lbs/Hp. A Corvette Grand Sport 5/3 lbs/Hp." In real life I watched an original Grand Sport outdrag GT40s out of turn 10 and down the front straight at Watkins Glen, thought they were both flat out. The FIA handles great, don't want to screw that up--but my 302 isn't any match for a big block in a straight line at present. The other issue about weight is that my car is heavy at 2550 lbs with about 5 gal gas, and the brakes go away and the toyo street tires turn to mush by the end of a 20 min session at The Glen--weight being a main culprit. Unless the weight goes down, more Hp=upgrading the brakes, which are stock with no air ducts at present.

Excaliber · #4 (**permalink**) 03-09-2003, 09:33 AM

Wieght is everything when it comes to racing! It affects braking, accelleration, body roll, polar moment and the list goes on.

I put cooling duct work on the brakes, "racing" compound pads, high temp fluid, heat shield for the master cylinder and four pot Wilwoods. Before that the brakes would be "toast" in about 10 minutes. I easily doubled the time with the mods.

Ernie

Bart Carter · #5 (**permalink**) 03-10-2003, 12:29 AM

Quote:

All in all, maybe a 100 lb difference bewteen the basic
289-302 vs. 351's after all.

Closer to 65 lbs.

Further reductions from earlier 289/302:

Aluminum heads -45 lbs.
Aluminum water pump -7 lbs.
Aluminum intake -18 lbs.
Mini Starter -6 lbs.
Aluminum flywheel -19 lbs.
Tubular headers -14 lbs.
Toploader to T5 -36 lbs.

Been there, done that, took measurments along the way.