351w Main Bearing Spacer Kit

Dwight · #1 (**permalink**) 11-09-2003, 11:02 AM

HAS ANYONE USED A FEDERAL MOGUL OR FORD MOTORSPORT SPACER KIT FOR THE 351W? IT ALLOW THE USE OF A CRANK WITH 2.749" MAIN JOURNALS. I INTERESTED IN A 351 WITH THE 2.749" MAINS FOR HIGHER RPMS. ARE THERE ANY PROBLEMS WITH THIS KIT?

Woodz428 · #2 (**permalink**) 11-09-2003, 01:58 PM

Why don't you get one of the Ford HD blocks, I think some of those come with the smaller Cleveland journal size? The spacers for Chevy smallblocks requires line boring, so the extra cost of the HD block might be a worthwhile expense.

TonyMadrid · #3 (**permalink**) 11-09-2003, 03:10 PM

Wouldn't regrinding the journals to .020 under achieve the same thing; smaller journals for higher revs?

Woodz428 · #4 (**permalink**) 11-09-2003, 07:01 PM

Tony, the 351W has a 3" journal. That would require a .250 (roughly) grind to get to the same diameter. That much and the oil holes start getting weird as well as other problems.

Dwight · #5 (**permalink**) 11-10-2003, 05:46 PM

THE 351 SVO BLOCK COST $1100 AND COMES WITH A SPACER KIT INSTALLED AND LINE BORED. THE OTHER 351 SVO BLOCKS WITH A 2.749 MAIN COST $1800. I HAVE A 74 MODEL 351 BLOCK. $$$???

Len Hurlburt · #6 (**permalink**) 11-10-2003, 06:27 PM

We have used several big bore short stroke SB chevy's (377ci) utilizing widely available spacer kits for the mains. These motors rpm all night in the 7 to 8K range without main bearing or other related failures. The spacers are a basically a snap-in type of installation and do not require a line hone. Although I do not have any first hand experience with Ford spacers, if they are similar to Chevy type spacers, you should have few if any problems.

Dwight · #7 (**permalink**) 11-14-2003, 02:40 PM

THANKS LEN

RobMcQuarie · #8 (**permalink**) 11-14-2003, 08:38 PM

Dwight,
We have used these on some of our customers circle track engines and they have worked very well in higher rpm usage. The Ford/Federal Mogul spacer inserts are only rough sized and do need to be finish sized in the block. They are not a simple bolt-in. They should be installed by a competent machine shop. We line hone or bore ALL our performance blocks as a matter of course to ensure true bores, so we see installing one of these kits as just an additional step in the block prep. With main studs, or better yet, we use a billet steel main cap girdle w/studs, to strengthen up the mains, you will have a very tough bottom end able to handle some decent rpm's.

I believe the main cap girdles to be very important. I have seen numerous non-girdled Ford blocks used for racing/hot street that have exhibited extensive cap walk, while the girdled blocks don't. I also recommend them for street driven strokers due to the increased power outputs and higher stress levels. We supply a MCGirdle on all of our customers stroker builds.

There are two different width spacers, depending on the thrust width type crank you are going to use, so make sure you match them up to the type crank you are planning to use.
Rob

Dwight · #9 (**permalink**) 12-23-2003, 04:08 PM

THANKS ROB

Chuck525 · #10 (**permalink**) 12-23-2003, 04:33 PM

IF TWO POSITIVES ARE BETTER THAN ONE, THEN SURE. I USED SPACER KIT ON A 74 WINDSOR BLOCK WITH 3.85 FORD SCAT CRANK, SCAT H BEAM RODS ETC. RAN CIRCLE TRACK AND MOTOR WAS AWESOME, JUST STARTED PULLING GOOD AT 5800RPMS.CHEVY GUYS WITH 383'S COULDN'T STAND IT.JUST MY 2CENTS WORTH

Perf. Eng. Eric · #11 (**permalink**) 12-24-2003, 01:28 PM

Dwight, We have used these spacer bearings many times with no trouble at all.