fms 351 crate engine upgrade follow along

vector1 · #1 (**permalink**) 03-07-2012, 07:04 AM

what we have here....

is a 351 crate engine as produced by ford in stock configuration that will be undergoing changes to enhance performance and take up some of my time in the process....

here is the replacement flywheel/clutch. initial weight of production steel unit is 47#'s, replacement will be 18#'s.

after completion and installation the unit will be taken to the BUTT dyno for evaluation.

possible transplants will be afr185 heads for x302 units, camshaft, and oil pan along with front timing cover for dipstick provisions lost with replacement of stock oil pan.

vector1 · #2 (**permalink**) 03-07-2012, 08:55 AM

i was concerned about using the afr185 in replacement of the gt40 heads because of valve clearance, then if i could use a different cam. here are the pics of the pistons in the crate engine, a pic of a probe piston that used afr225 heads and a healthy 244/244 .500+ lift cam, so i don't think using the afr185 heads is going to be a problem. also included is a piston/block pic of a production f4te piston, with no valve reliefs so i don't believe the larger valved head could be used on it. the afr heads should also raise the compression to around 9.5 with the 58cc chamber vs. the 64cc on the gt40s.

the cam was installed 2R, or 2 degrees retarded, so a different cam and a little advance should all add up.

anybody want a good pair of gt40 heads for only $750 with 1.6 rockers, pedestals, pushrods i can ship them in the afr box.

the gt40 heads did have a larger inlet than the afr185 heads, but i imagine the smaller 1.90 valve in the gt40 caused the runner to be smaller further down than the afr185's 2.02 valve.

Cashburn · #3 (**permalink**) 03-07-2012, 10:49 AM

What oil pan do you intend to use? The Canton and Moroso pans have the dipstick installed into them and no need for this timing cover change.

vector1 · #4 (**permalink**) 03-07-2012, 11:34 AM

armando pan, for some reason i didn't think to specify a dipstick when i purchased it a few years back. i have front covers to choose from so it is no problem, so far.

vector1 · #5 (**permalink**) 03-07-2012, 01:05 PM

the installed cam was a fms z303 so it is going back in. pretty similar to what a cam maker recommended. the cam was installed 2 degrees retarded so it is going back in with 4-6 advance.

Curt C. · #6 (**permalink**) 03-07-2012, 01:15 PM

I have the old FMS 385 HP 351W crate engine with AFR 185 heads. I did end up flycutting the pistons as the tolerances were way too close. My cam is different than yours though - hydraulic flat tappet M-6250-A351. Easy enough to do. There are tools out there that make it a snap.

vector1 · #7 (**permalink**) 03-07-2012, 02:00 PM

mine is pretty old too, circa 2004 sticker on the side, or what i thought was old, came with a roller setup though.

vector1 · #8 (**permalink**) 03-08-2012, 07:52 PM

the z303 valve lobe measures .345, with 1.6 rockers lift would be .552, with 1.72 rockers which i have lift would be a calculated .593. i shot an email off to afr since their afr185 heads list max .600 lift to see if i could run .593 lift which they said was fine. since the chip is now a conservative 6000rpm i don't think it will hurt to run the higher lift rockers. the 1.72 showed good marks on the valve stem when put through the lift range and didn't want to risk changing to 1.6 and having to change pushrods also. so far so good!

vector1 · #9 (**permalink**) 03-17-2012, 10:27 AM

here is a pic of the finished product. waiting for flywheel balancing to reinstall. another guy running similar setup with solid roller more lift & duration is running 10.7 in a street car, presume 80's mustang.

vector1 · #10 (**permalink**) 03-20-2012, 08:25 AM

had the lightweight flywheel balanced at a cost of $75 to match the crate flywheel. the guy who did it or the business ari in grandview, mo has been there for 30+ years, he did a tilton flywheel i had about 20 years ago and after i took the stuff over to him i visited another guy who i sold some parts to and he still had the flywheel, with 50 oz. of heavy metal welded to it! the business owners son is now getting ready to build a ffr cobra with a dart blocked 427 so we chatted a bit, when he left 'nam he went to purdue and bought a gt350 and said there were 3 cars on the showroom floor, a 260ci cobra, a gt350 and a hipo mustang! said he couldn't keep up with his college buddy in a 260ci cobra. anyway, he builds lots of ford small block stuff for the circle track racers and has tons of go fast stuff from 30 yrs accumulation.

here is a pic of the flywheel assy with the massaged weight, and a pic of the bellhousing with the bottom cut off which should put it right at the bottom of the jbl frame. the oil pan is still expected to be 1" below the frame.

i determined that i can use the flat faced throwout bearing, looking at the mcleod pressure plate the fingers are curved on the end which mimics the stock fingers. if the fingers were flat i would have needed to use a rounded throwout bearing which is usually the case with the smaller pressure plates.

Richard Hudgins · #11 (**permalink**) 03-21-2012, 01:15 PM

Mark,

Why are you advancing the cam timing? I thought the crate engine power band worked well with a 3:73 rear ratio. Or do you have a 3:55?

Of course I like rev's. The more the better.

That is why I think the best engine for one of these would be a Judd 5 liter GV5.

vector1 · #12 (**permalink**) 03-21-2012, 03:44 PM

hello richard

i inquired about a cam from a cam grinder and he spec'd pretty much what was in there except a 108 lsa whereas the z302 cam uses 112, probably for emissions or efi. i told him it was installed 2 retarded and he suggested 4 advance, by the time the chain stretch and everything else is accounted for it is probably pretty close anyway. the 6g rpm chip doesn't lend itself to too many rpm's, and the engine simulator indicates peak hp around the mid to high 5's anyway with that cam. doesn't leave much room to keep the pedal down

.

judd 5l? thought i was doing good to remove the truck flywheel....

vector1 · #13 (**permalink**) 04-04-2012, 07:22 AM

Fired it up today! After the initial oil priming leak from one of the AN fittings and a couple small coolant leaks it fired right up, then died, and again, and again. I knew i could get it started off the accelerator pump and would have to wait for the fuel line to fill, but i forgot i had disconnected the line at the back to break the siphon.

Definitely sounds much better, zippier, and oil pressure is now 50#'s. Ford uses a high volume oil pump on their crate engine btw. Before i removed the engine there were -8 oil lines through a filter and oil cooler, producing 40#'s reading at the inlet of the block. I used -10 lines through a filter only, not using the cooler as the oil pan & system hold 9-10 quarts, maybe install for looks but not really needed to cool the oil imo and i could move the filter to a lower position, keeping the lines filled with oil. The oil pan is about 1.5" below the frame, the only thing.

Haven't driven it yet as I have to bleed the clutch but that may happen today.

vector1 · #14 (**permalink**) 04-04-2012, 06:31 PM

drove the car today! after all the modifications--afr185 heads, 1.72 rockers, advancing the cam, and lighter clutch system and flywheel, the butt meter says time and money well spent! even though it was cool today and the tires are old with the 335 rear tires it is so easy to get squirrely. this engine is in the low 400's on hp i imagine and the 6000 limit comes up pretty quick, seems to hit about 3-4g and just takes off.

the fms 392 crate engine with upgrades i believe is an easy 500hp.