Weak point of 2 valve 4.6 motor.. RPM?
- Thread starter OinkAodeOink
- Start date
So the general consensus is that these motors should be kept at or below 400rwhp.
Remember, mine is an auto trans, meaning it wont be as hard on parts, or put as much shock on parts, as a 5 speed car might. Also, the auto will soak up more power, so realistically, 400rwhp from a stock auto trans should put things around 525 flywheel or so.
Remember, mine is an auto trans, meaning it wont be as hard on parts, or put as much shock on parts, as a 5 speed car might. Also, the auto will soak up more power, so realistically, 400rwhp from a stock auto trans should put things around 525 flywheel or so.
White Stang
Member
Detonation is the killer of most Mod engines and it usually is the piston that goes. Stock Mod engines offer no forgivenes 
Also Push rod engines usually are the ones that throw rods from what I've seen.
Also Push rod engines usually are the ones that throw rods from what I've seen.
So would you say the mod motor's are less forgiving then say a 92-up 5.0?
The 5.0's have the hyper pistons, cheap rods and cast cranks, but seem to take a a decent amount of abuse, and usually the block is first to go.
The 5.0's have the hyper pistons, cheap rods and cast cranks, but seem to take a a decent amount of abuse, and usually the block is first to go.
totally off topic, but I just noticed you and I have done the same deal on the hood... and here I thought I was the only other one with the idea (besides saleen) lol.
I might get rid of the white divider on mine, not sure yet..
View attachment 518072
I might get rid of the white divider on mine, not sure yet..
View attachment 518072
White Stang
Member
No Modular blocks are actually a better built engine everything equal. Stock modulars are just not forgiving to detonation due to their week internals. This is why you can have a piston break and you would not even know until oil works past the piston into the heads. The blocks for modulars rarely get damaged where as push rods will shoot the rods through the bottom of the block on a regular basis.OinkAodeOink said:
I would say yes….as a whole, the modular engine is less forgiving for the most part than the OHV. The 5.0L has the same cheap hypereutectic pistons, but their design is a lot beefier and carry a lot more meat around the upper ring landings, where the mod motors tend to go. The rods in a 5.0L are actually pretty good. Much better in comparison than the spindly toothpicks that the modular engines are equipped with. The problem with the mod motors, are that once the piston goes, it usually takes the rod with it. As far as the crank….both the SOHC and OHV engines use a cast nodular crank. The SOHC crank just happens to be a little beefier and recessed deeper into the block adding to its strength in comparison.OinkAodeOink said:
Each engine has its flaws. For the OHV’s, they have problem keeping head gaskets in check as well as the block cracking along the lifter galley when the power starts to climb. The stock rods and crank are good until about 450rwhp, but I wouldn’t rev the crap out of it. The stock 5.0L block usually pukes at around 500-550rwhp. Sometimes less if the mains are not reinforced.
The modular engine on the other hand has the weak rods and pistons to contend with, but don’t have any of the head sealing issues that the OHV engine does and although it’s said the block is good for around 550rwhp, but I think this is more of a combination of the block and stock crank, that limits it, not the block alone as I’ve never heard of an iron block breaking.
Hows that for the run down....
Would it cost effective to install a set of pistons/rings and rods, and bearings, and just reuse the stock crank, or would the crank limit me that much?
Atleast now I know what im getting into, and will probably just keep it detuned to 350 and be happy with it..
My goal was to break 11's with the stone stock longblock and turbo (and supporting air/fuel parts) untouched otherwise. this would be on slicks, stock 327 gear, tranny, ect. I doubt 350rwhp will cut 11's, with my plan.
Atleast now I know what im getting into, and will probably just keep it detuned to 350 and be happy with it..
My goal was to break 11's with the stone stock longblock and turbo (and supporting air/fuel parts) untouched otherwise. this would be on slicks, stock 327 gear, tranny, ect. I doubt 350rwhp will cut 11's, with my plan.
jimfitzgerald said:
lol, ya your right, I should have rephrased that.. Is it worthwhile to leave the stock crank? I suppose once its all apart, it's best to do it right., even if it requires more $$
If you're building it on a budget and not going to exceed 500rwhp...and your stock crank is in good shape, then there's no reason whey you can't just upgrade the rods and pistons (that's what I did http://www.modularperformance.com/m...e=MP&Product_Code=MP100-2100&Category_Code=EK). Put the $400-$500 you save on the forged crank towards something else in your build up. 
