Dept. of Boost...question(s)

[tjm73]

First off, not sure if this is actually tech. If it isn't mods please move to where ever you think it really belongs with apologizes for posting in the wrong sub-forum.

DOB, I've had a thought and wondering your thoughts on my thought. Because of your boost experience and your no BS info (props on that) on your website, I'd trust your insight.

When the Coyote came out, rod strength became a minor concern virtually overnight. As you have said it was now a fuel/knock issue. Since street boost with street gas is on the verge of popping 2V and 3V engines, would an otherwise stock 2V/3V engine with Coyote rods stand a better chance at surviving? I mean there are absolutely ridiculous numbers of 4.6 2V/3V engine cores across America. And the buy in is notably less.

Example, a dude takes a totally stock 260hp PI headed 4.6 2V in all it's 260hp glory (or a 4.6 3V) and pulls the engine. Assume the bores are within spec and just get honed and re-ringed. The crank is also within spec and so will be reused. in other words, owner reuses the crank and pistons but puts Coyote rods in it. Of course it gets balanced. For a rebuild with the added cost of a set of Coyote rods and a balance job would this engine now be real world, real pump gas safe for up to around 600 hp at the crank? I'm thinking this could be a budget path to a 600 hp rotating assembly with reliability. If tuned properly and responsibly.

 

[Wes06]

IIRC the stock pistons in the 3v are only slightly behind the rods in terms of when they will pop. not sure on ##'s but probably best to do both minimum, i mean your already there with it apart, but re-using crank and everything else is fine

 

[1fastTbird]

I agree with Wes06. It becomes a question of "what is your time worth?"

 

[BruceH]

You were right, most of the time talking about parts isn't tech and this is one of those times.

The 5.0 rods are beefier and stronger than the 3v rods. It's the reason a boosted 5.0 can stand more power than a boosted 3v. The Boss rods are even stronger.

However, if you have the motor apart for a build and have to rebalance anyway might as well either use Boss rods or ebay special h beams with decent bolts.

Everyone always breaks the rods, never the pistons. If you want to do a stock 3v piston with 5.0 rod build go ahead and be the tester, lol.

All we can do is guess. My guess is that the weak link in a stock piston wouldn't be the material it's made of (unless you had a fuel or spark related issue causing detonation). My guess is that it would be the lack of necessary thickness in the distance from piston top to top ringland. At some point the cylinder pressure would expose this next weak link.

Where that point is only you can find out, lol.

 

[Department Of Boost]

I don't think you could get 600hp out of a 2v PI motor. Too restrictive. You're boost would be too high for pump gas.

I myself would never use a OEM rod if I had a motor apart and was looking for 600hp. I hate doing stuff twice. And I would only risk using stock pistons if Lito was tuning.

 

[01yellerCobra]

I knew one 2V that made over 600rwhp. It had fully ported PI heads, custom cams, full exhaust, Novi 2K, and race gas. Boost was some where in the mid 20's as was timing. It made me glad I stepped up to 4 valves.

 

[Sky Render]

If you don't have time to do it right, when are you going to have time to fix it?

At least, that's what I've always thought.

 

[eighty6gt]

I should have my boss rod stock piston 3V engine running before May 31 of this year, however will only be ~500rwhp @ 11-12 psi on 94 octane fuel.

 

[tjm73]

All valid points.

What if you were just rebuilding all stock spec with the intent of no more than 10psi?

This is just kind of a metal exercise.

 

[Department Of Boost]

I knew one 2V that made over 600rwhp. It had fully ported PI heads, custom cams, full exhaust, Novi 2K, and race gas. Boost was some where in the mid 20's as was timing. It made me glad I stepped up to 4 valves.

The discussion was about stock motors with rods and maybe pistons running pump gas.

 

[Department Of Boost]

All valid points.

What if you were just rebuilding all stock spec with the intent of no more than 10psi?

This is just kind of a metal exercise.

Yeah, for sure put the good Yote rods in. They're super cheap.

 

[eighty6gt]

METAL!!

For a very mild build with the engine open there's no reason not to run the boss rods in a 4.6 (which are now listed as F150 rods) - I'm sure they are the same cost as the 2005-2010 3v rods. Also, wonder if the latest iteration of the mustang 5.0 rods are also the same parts. I bought the boss parts as they were the only certain option available back in the day, and still cheap.

That said, I would probably not build another 4.6 if this one melts down, I would seek out a 2015+ spec 5.0 truck engine. The F150 is one of the most produced vehicles in north america, and pull out engines should be ubiquitous in due time. More and more folks are going 5.0 in the early S197's. Stock mustang exhaust is always easy to find for a set of headers and a midpipe. I have enough supercharging stuff around that I can sell an entire blower kit for about $1500 and go to DOB and an M122 which on a 5.0 will be very stout.


2V, I wouldn't go there any more. Same issues as going with a 5.0 and much less power.

 

[tjm73]

Yeah, for sure put the good Yote rods in. They're super cheap.

Not sure if you are busting my stones or serious.....

 

[Department Of Boost]

Not sure if you are busting my stones or serious.....

No, no!! Not at all. If I was doing a "stock" rebuild to make 450-500hp I would use the BOSS rods. Keep the build as cost effective as possible.

Playing around with 600+, I'm throwing beefier stuff at it. But at 600+ you're not really doing anything cost effective anyway. What's a couple more bucks!!??

 

[tjm73]

Ok. Cool. I don't have deep enough pockets for a 600+ hp anything. But a clean '03-'04 5 speed 2V GT coupe with just a PD blower could happen and be a fun street car. I would need to be selectively...ummm...."cost conscious".

I bought a decent '91 Fox hatch two years back and I'm just not feeling it. I think I'm going to sell it and move into an '03-'04 GT Coupe, possibly a Mach 1. If I go with the GT, I want to put a PD blower on it. If I go with the Mach 1, I won't do much to it at all. Wheels, gears, cat-back, shifter, a tune, suspension, that's about it.

 

[Department Of Boost]

Ok. Cool. I don't have deep enough pockets for a 600+ hp anything. But a clean '03-'04 5 speed 2V GT coupe with just a PD blower could happen and be a fun street car. I would need to be selectively...ummm...."cost conscious".

I bought a decent '91 Fox hatch two years back and I'm just not feeling it. I think I'm going to sell it and move into an '03-'04 GT Coupe, possibly a Mach 1. If I go with the GT, I want to put a PD blower on it. If I go with the Mach 1, I won't do much to it at all. Wheels, gears, cat-back, shifter, a tune, suspension, that's about it.

The problem with that is the blower options for those cars/motors are pretty crappy.

 

[eighty6gt]

I was going to say if you fancy that era of car get a mach and do full exhaust. They sound great with the mid mounted mufflers, maybe make 325, 350 hp, keep up with the modern pickup trucks. DOB is right about the blowers, rather uninspiring. Lots of work and you don't get as far as with the later cars.

I once bounced the idea of trading my PD bullitt for a boss 302 off of a friend who works at Ford and drives everything, he said I wouldn't really be happy with a n/a coyote.

So you go round, and round. Just keep the fox!

 

[Department Of Boost]

Fox body with a 3v running a GT450 kit FTW.

 

[tjm73]

Fox body with a 3v running a GT450 kit FTW.

This, the basic idea anyway, has crossed my mind. Iron block 3V's are real easy to come by. Yeah aluminum blocks will save a little weight. But iron blocks will save a little money and when going from an all iron 302 to an iron/aluminum 3V it's not much different and if I swapped a 351W into the car it would weigh more than the iron block 3V. So to me it's not a huge deal to have the aluminum block.

Hmmmm....you've raised a thought I've not considered. The Fox I have is decent, but definitely not great. I may hesitate to say it's good even. But it is pretty solid and that also makes it a star candidate for doing a 3V swap. It's definitely not a "restoration" bound car.

And Foxes will soon be getting the restoration treatment. In fact I think some already are. As they should be. Some stock ones should remain. Just not this one.

 

[eighty6gt]

Problem with a fox is you rebuild the entire car from pieces when you add power. Trans, brakes, and the suspension is as far behind the S197 as the S197 is behind the S550.

Sometimes a guy just has to say things are good. The fox would be a really fun car with some AFR 185's, a stout cam, full exhaust and edelbrock intake. Similar power to the Mach but a lighter vehicle with more NVH.