Good morning everyone,

I'm rebuilding my first engine. The junkyard said the engine was out of a 1994 F250, sold as a core due to a bad miss I ordered a rebuild kit from ebay. I'm doing alot of reading, but never ran across the difference in piston ring gap for 94 - 97. It looks like the seller sent me a kit for an older 5.8. The piston rings didn't work, so 30 seconds of research and I've learned of the Ford Metric/STD swap in the late 90's with the roller block. I'm outside of the 30 day return window. Before I order metric piston rings, is there anything else I should concern myself with in this kit? It looks to be a late 80's kit, because the rear main is a 1 piece. I'm fairly certain the same rods/crank were used, but I'd like a confirmation before pulling the trigger. Any reason the bearings/seals wouldn't work? Cam bearings worked fine. Bought a 240 grit flex hone. The bores had a .002 taper, so I opted to keep the bore.

Heads: 185 AFR 58CC - SKU 1388

CAM: Advertised Duration (Int/Exh): 272/280; Duration @ .050 (Int/Exh): 221/229; Gross Valve Lift (Int/Exh): .549/.565; LSA/ICL: 112/108; Valve Lash (Int/Exh): Hyd/Hyd; RPM Range: 2200-6200;

The machine shop said I'd run into valve clearance issues. I know that it's hard to determine at this point without someone else having done the exact same set up, but given the lift of the cam, does anyone have personal exp on the likely hood (I'm going to check the clearance either way. .080 on the intake and .100 on the exhaust?) I'd rather buy a set of pistons than spend 3 hours fly cutting.

May be 2 early to give advice on the subject (prior to starting the engine), but the CarTech books are amazing!

 

The block will have F4TE stamped on it, on starter side, are you going Carb or EFI if its Speed Density(EFI) that cam wont play nice without a tune

 

Sniper efi throttle body. I'm hoping the carb can self tune with the heads/cam. I was under the impression this cam was more on the mild side. Do you think it's 2 aggressive for a daily driver?

 

this is what they say about the ford 303 cam(aka, alphabet cams) The Z303 camshaft. This cam is a lot like the X303, but even more extreme. This came has a ridiculous 552 intake and exhaust lift. You will definitely need to notch your stock pistons or buy aftermarket pistons that can even clear that much lift. Aftermarket heads are strongly recommended with this cam, otherwise, you’re just wasting your money. If you need the best drag racing cam possible, then the Z303 cam is for you.
it has less lift than your cam your looking at .549/.565, duration isnt helping, if this is going in a truck you will sell it when your done, see below what options you have, quite a few

posted by Conanski

 

My machine shop (Engine wash/cam bearings) said the cam would be great. Lunati said the same thing, lol. I’ll just send it back. Amazon had a great deal on it for $200, so after checking with the manufacturer and machine shop I thought I found a deal. I’m Not looking to drag race lmfao. It’s a daily driver, which works out to like 200 miles round trip.

420+ horses and 20 mpg..... this cam doesn’t seem to fit the bill according to your chart. I’ll do some more research on it.

 

Thats a big cam, with those heads, would be a pretty good screamer. Keep the cam and rings, buy pistons, problem solved.

 

I spent some time on summit and reached out to the machine shop. It’s not worth an extra $1000 between balancing the engine and buying pistons. I’ll find a smaller cam.

thanks guys,

 

'420+ horses and 20 mpg'...I see your problem, they have the zero on wrong side of the 2, for MPG...should be 02 mpg, lol, to use any of that cams torque, going in a 150/250 truck or car, and not trying to get you to change heads, and you may already know, but AFR now has none CNC 185(Enforcer) SBF head, its $700 less than the CNC 185(Renegade)
185cc SBF Enforcer Cylinder Head - Air Flow Research

 

If youre not balancing whether you do pistons or dont, youre doing it wrong

@torqta i had no idea those heads exsisted let alone for that price. Reeeaaally wondering why ive spent 20 hours on my p heads now. Am curious why they dont offer the 165 as cast.

 

wow, thanks for the link!! I’ll do some reading on them! I didn’t know about the heads and I just spoke with AFR yesterday. So it’s the same head without the cnc work? So no long term loss, would be great. That growth is still there.

 

why would you balance an assembly you removed from the engine?

 

You mean why wouldnt you? Stock engine was designed to be "good enough" for production and only turning 4k rpm. Beyond that, if youre not balancing, that means youre not reconditioning the rods, replacing rings or bearings or anything huh? All of that changes the balance, nevermind the fact that the factories idea of balanced is passable at best. Im not telling you what to do, but if you can afford to drop 2k on a set of heads (that should be 165s imo) theres no excuse not to do the basic necessities to the bottom end. Were not talking machining valve reliefs, or cutting for threaded guides or revised oiling or any trick **** here, this is basic engine maintenance 101, and its so cheap it is just not justifiable to not do it. Thats like saying im rebuilding my engine but not getting a valve job, it ran when i pulled the heads. Really, you probably should replace the pistons, thats why i suggest that as an alternative. Stock cast slugs are decent, but mediocre and are a wear item as much as rings / bearings / or any other consumable. In a performance setting, you have to really be careful about ping, and their longevity might not end up being what you were hoping.

 

Machine shop said there was no reason to balance the short block assembly. How do engines go 200k miles on stock balance if they’re such poor quality? What would they get if the balance was done in a machine shop? 220k? 250k?

a friend has a stock 351 roller with 150k and 6-7 pounds of boost in a hatchback. It’s a daily driver with 20k miles on the assembly since adding the boost.

I thought a ring/bearing kit was a common diy repair?

 

Depends on how many corners you want to cut i guess. For starters, i would find a new machine shop. Youre putting afr 185s on a 351 with 280 @.050 duration cam. Thats a 6500 rpm engine. As you increase rpm, the forces upon bearings, rod bolts, main caps increases exponentially. Even if youre not boring or shaving the crank i would NEVER stick an engine back together without having the cylinders honed in a machine, and the rotating bits mic'd for roundness, at least any engine i was keeping.. Heat cycles and wear and tear slowly deform the rods over time, this is why you recondition them. The pressure on the rod journals is not the same in every part of the rotation, this causes the crank journal to oblong, also the cylinder to taper. The hone is needed for the new (or old) rings to seat and rotate as they should. The more power you make, the faster you turn it, the tighter tolerances have to be. More power is more heat, more heat makes stuff grow, stock cast pistons are designed within a margin, go outside that margin, you stick a piston, butt a ring etc. Oil film strength and thickness becomes more important with effective bearing load and rpm. Too loose you cook the middle of the bearing, too tight you seize it. Factory blocks are almost always .010-.020" out of square, that means say #1 piston is .012" in the hole, and #8 might be .018" in the hole. Chamber volume can be 1.5cc off from port to port in the same head. Engines from the factory seem to be within an oz of balance, thats good enough for the AVERAGE pickup engine to run a normal life span, not so much a hot rod engine in which you shoot for a tenth oz (international was specifically know for having horrendous imbalance problems). On top of that theres stacked tolerances to account for, what makes one seemingly identical engine a great engine that runs forever and one thats junk? Have a great first hand comparison. My dads 63 (my great grandpas from new to ~75ish) In 1970 the 292 bent a rod, was knocking.. only a 7 year old pickup. Put a reman'd ford engine in it, when the speedometer died in 1988 the pickup had 488,000 miles on it, dad drove it every day until 2004. Why such different results from the same engine built in the same factory using the same procedures?

If theyre such high quality, why are you rebuilding it at all?

 

I was looking to stop rpm around 5800-6000. I have a Holley sniper carb with an electronic controlled diz. I can limit the rpm to protect the stock bottom end.

i ball honed the engine and polished the crank with 2000 grit. all done diy with 0 experience, so it might fail, might not. Hot rodding is a dying art/hobby, bc it’s so expensive and people have quit relying on their own abilities. If it doesn’t work out then I’m out $80 (rebuild kit) and time, but I’ve gained a ton of knowledge and experience. Well worth the gamble versus alternatively spending $1300 at the machine shop. $200 wash, 300 crank, 100 for pressure check, $100 for flux, 250 bore, 350 balance.....

I Mic’d the Crank/bearings. Pistons are in spec as well. Main bearing journals are 2.2998. New Piston Rings are .016. Piston to cylinder bore is .020. Engine building is pretty simple for the most part. stuff regarding cam measurements Is a bit tougher to follow without the experience.

I’m doing rings and bearings bc the engine had leaks, low oil pressure, and low compression. can’t beat it for $200 with a stock bore.

im pulling the 292 y block Under the hood to install this 351. I’ll be doing the same thing for the 292 if it specs out in a similar fashion. I’m sure it’s not a std Bore. It runs great, doesn’t over heat, has good oil pressure, just has a ton of blow-by. So I’m going to open it up. I’ll hit it with some Mummert go fast and forced induction. Then Start my wife’s dream cobra car. Powered by 1 of my favorite engines, a hopped up y block

I appreciate the advice. if the engine didn’t spec, I would’ve taken it to a machine shop. I’m a gear head with more projects than money, so I’ve gotta save money when and where I can. I don’t believe I’ve cut any corners yet.