I'm wanting to build another 460 for my truck on the side. I have never built a V8 before and figured I'd build one when I had a vehicle to use one in. And now I have one.

Truck is just an 86 F250, T19, 4x4. No lift and don't plan on one unless it was small like 3" or so.

Locally we have a mudrun in which several of my friends partake in the stock class. I will add that it's not a mud bog, it's a mud run. I think it's something I would really enjoy.

The owner of the land which the event is held on I know well and it's about as sopping wet as it can get here in south west Missouri. Yesterday I took my truck through it as a test, just like I would in the mudrun. What I noticed is I hit about 5000 RPMs and steadily held that RPM across the pit. I wasn't gagging it real hard that's just where it revved to and in a sense felt like it was natural. I was pleased with it's performance. But I know I'm going to need an engine built to withstand that occasional abuse.

I'm not after power although I know it's going to happen. I just want a 460 that can withstand 5000rpms. I have been searching the web and over on the 460.com forum quite a few say it can handle 5000rpms as is but I think most of their cars/trucks stay on the drag strip for the most part. In my quest for answers I keep seeing claims of "760hp on shot peened rods with aftermarket bolts" and it being said that SCJ and Truck rods can handle up to 7800RPM with the proper oil pump. I'm the one who is asking the questions and I'm definitely not disagreeing or arguing with the information that's out there, but that doesn't sound right to me.

I really don't know the weak spot(s) on 460's. I guess that should be where I start.

 

All OHV engines have things in common.

One of the problems with revving the engine really high is the strain on the crankshaft, rods, and rod bolts. As the engine is running, the piston goes to the top of the bore, stops, and changes direction and starts going down in the bore. It does the same thing at the bottom, stopping, and changing direction. At low rpms everything is ok, but as you go higher and higher, the forces it takes to make the piston stop and change direction get very high. That's why you are hearing talk about rods, rod bolts, full floating pistons pins and you might hear about forged crankshafts and modifying the main bearing caps with girdles and such. They are trying to hold all this together at high rpms.

On the stock engine the natural rev limiter is usually the valve springs, especially when they get old. The valve train has to do sort of the same thing as the pistons, the valve has to open, then turn around and shut. The only thing that shuts the valve is the spring. As they get old and weaker, and the rpms get really high, they get to the point they are not strong enough to bring the valve back shut all the way. That's when you start losing power when you get way up in rpms on a stock engine, it's called "valve float" and is sort of a natural rev limiter. When the valves start hanging open the power will level off.

So the camshaft and springs in combination will be the rpm limiter of your engine. If you want to be sure your engine will hold together and not get over-revved during a run while you are concentrating on going through the mud, you can get get ignition systems with rev limiters built in to save your engine.

If you want it to go higher in rpms, you are going to have to spend some money in beefing up the bottom end of the engine.

P.S. I forgot to mention, as you go higher in rpms, stock flywheels and flexplates are only rated for certain rpms. They have been known to fly apart. Of course they make higher rpm rated racing flywheels, but they have been known to fly apart also, so they make special bellhousings and blankets to go around these components in case they do fly apart, they can come right up through the floorboard, or fly out from the truck and hurt a by stander on the sidelines.

 

5,000 rpm is nothing - all of the engines can handle that. 6,500rpm isn't a problem either. It's just that these engine stop developing power after (around) 5200 rpm because they "can't breath" well over 5000. It's a matter of the cylinder heads and cams used. But in a street driven truck you don't want a truck that is built to run over 6500 rpm because you give up driveability and performance on the "bottom end" under 2500 rpm where you spend most of the time.

The basic engine build recipe for a 460 cid streetable truck is to use a dual-plane low-rise intake manifold, a cam "under" or around 226 degrees (measured at .050" lift), a carb on the 750 to 800 cfm range. Headers and free-flowing exhaust, and a good ignition system. Lastly get a good set of cylinder heads like TFS Street 290, or Edelbrock Performer, or have your iron heads ported and increase valve size.

This will get you around 450 hp and a nice power range of idle/1000 to 6000 rpm.

The stock crank can handle up to 1,000 hp so no need to upgrade. The rod bolts are the weak link, so go with ARP or similar performance bolts. Is it were mine, I would go with forged pistons during the rebuild.

 

Dave mentioned them, but don't miss the rods. It cost me $100 to have my rods shot-penned at a facility that shot-peens parts for the aircraft industry here in Tulsa. The guy that runs the place said a lot of other things will fail before those rods let go. And, if you are in SW Missouri you could come here and have that done.

Speaking of SW Missouri, are you as SW as Southwest City? My wife used to live just west of there, just into OK.

 

Thank you for taking the time to write such a detailed explanation! After reading through your overview and applying it to my objective it doesn't seem so sophisticated as I originally thought.

Never thought of a rev limiter although I knew they were available. Good suggestion. You hit on a good point about going though the mud pit, the more focus I can apply to driving the truck the better. That gives me quite a lot to think about.

I would like to stay with the D3VE heads. There isn't much reason for me to make a lot of power because it has about all I desire as is and like you said about driveability. It's the durability that's my primary concern. I have read about porting the D3VE's and plan on having it done. I read about and contemplated SCJ valves but don't currently know enough to make a decision. I also don't know the approximate cost so I don't know if I will find it cost effective.

As for the intake manifold I was thinking about an Edelbrock Performer. Seems like it fits the bill pretty well.

I have a new Edelbrock 750cfm manual choke on the current engine which I like and want to use on this engine. Just throwing that out there. I know people are somewhat diversified on carburetor manufacturers. An Edelbrock is just what I prefer. It seems to have the characteristics that I value the most.

As for headers I have read that since it's a truck and will be in the mud and dirt a bit that ceramic is what I need. Which I can swing if need be even though the set of ceramics I looked at are around $375.

As for a cam I was just going to call up Comp Cams and tell them what I'm doing. I imagine the profile wouldn't add much if any lope to it. I don't desire much performance nor do I want to effect driveability in a negative way.

Rod bolts are the weak link, awesome. I'm going to do some research on this area then. And 1000hp on the stock crank. Wow... That's awesome. I won't have to worry about that then.

I was thinking about going forged pistons as well. This also brings up compression. Since I'm strongly leaning towards utilizing modified D3VE's, the compression seems to need a little improvement. I was thinking 9.2:1 or 9.5:1 from what research I have done. That will should support the cam a bit better and still run on 87 octane. At least I presume anyhow.

I was wondering if shot peening would suffice, thanks for sharing that information. I know some people question it but I also have the idea of cryogenically treating them on top of shot peening. Some are non-believers and I'm no expert on cryogenics but for the cost of the service I don't see what it could hurt.

I'm near Branson but that doesn't scare me off. If you know a reputable guy then that makes me confident enough in his services to make the extra effort. I'd rather do that then pick someone at random and end up with a poorly shot peened set if rods or worse.

What we haven't discussed here is balancing. I would think that balancing might provide some added durability.




Thank you guys for taking the time to discuss this with me and lend me a helping hand. I could have placed this in the 460/429 specific section but I chose the Bullnose section because of course my truck is a Bullnose but also because this section seems to have some really nice and highly educated members.

 

The place that did my rods was United Plating Works, and I talked to Fred Block, who is the president. Peening engine rods is not their business as they do things like shot-peen aircraft components. However, he took the job on for me - whom he didn't know. So, call and ask before driving from Branson.

 

I tried to reply to this twice on the weekend, but the forum ate my rather lengthy reply both times... LOL
5000 as already mentioned is plenty safe for a stock 460 bottom end, put some good bolts in the rods and roll with it. My high limit is set at 5500, and it has seen LOTS of use.
No need for a non stock oil pump, a high vol will just suck the pan dry, and a high pressure will have you splitting oil filters, my engine is built to stock in the bottom end, and runs 80 on cold start and 65 at hot idle with 0W40 in it.

You like me, probably have E6 heads, not D3's, not that there is a whole lot of difference. Mine are ported per the mad porter's guide now.

For the intake, a standard performer is basicly an aluminum copy of the stock manifold, not a whole lot of gain there.

My engine is probably exactly what you want. It is as follows:
9.5:1, performer rpm intake, 750 edelbrock el choke carb, cam is a comp extreme 4x4 256/262, .514 lift, their smallest 4x4 grind, 1000-5000 range, valvetrain is the kit that comes with it. It is a very simple, not too expensive build, and kicks out a solid 400 hp @ 5000, 400 ft/lb by 2000, and peaks at just over 500 at 4500. It is well behaved, pulls 18" of vacuum at 500 rpm, and runs on 87 all day long. My bottom end is a 97, so it runs a slightly taller pin height in the pistons which allows for longer dwell time, and builds better torque, how much better I have no real idea.
I have el cheapo hedman headers on mine, as they were one of the few that had manual specific headers, they've been on it since 07 and they still are good and solid, but my truck does not see road duty, ever.

I do have a fancy shiny Summit branded sfi approved damper on it, but everything on the back end is stock, there are no fancy bellhousings that are bolt in for these trucks due to the hydro clutch, and Centerforce's sfi approved flywheel was near the $600 mark last I looked at it.

 

One comment on the D3 heads.
Note that they have "large chambers" around 97 - 100cc (which equals low compression. Low compression is good for low octane gas but bad for power). Since you said you were replacing the pistons you need to take the cyl head chamber volume into account when you spec your pistons. Your at around 8:1 compression now, you want 9:1 for perfomance on regular gas (no more than 9.5:1).

Also be aware, that the D3 heads do not have hardened exhaust seats. So if you plan to tow, you may burn up a valve. You can have hardened seats put in when the head is rebuilt.

For a performance engine you would also want an "adjustable" valve train, so your heads need to be machined to allow for screw-in rocker studs and guide plates.

lastly, the D3 heads have about the worse flowing exhaust port of all the models. The ports can be enlarged ** though and usually most performance seekers will put a larger exhaust valve while everything is getting machined.

So after all this - your not that far away ($ wise) from a nice set of aftermarket aluminum heads.

** See this site for more info on DIY head porting (unfortunately Scotty now requires a small donation for access). Re in"Car"nation High Performance - Home

 

Thanks for their information. I'll be giving them a call when this is underway.


It's great to hear your experience with running a 460 at those RPM's. This information is pleasing to say the least.

I had read that about oil pumps. I will look for a high quality standard oil pump and call it good.

I very well could have E6 heads if that's what it was supposed to come out with. When I bought the truck I searched for the specifics on everything and D3VE is what I came up with. There was said to be a tab as I recall but with the heads on the block it makes it either impossible or hard to find because I couldn't find it. Or, I may have overlooked it.

Your build sounds perfect really. Those numbers are crazy! That's almost doubling HP and adding well over 100ftlbs of TQ. If I end up with numbers like that I would be just fine with it. I wasn't expecting to have the best of both worlds but I'll take it. I'm really liking these 460's.

I mentioned compression and cylinder head volume earlier on in the thread so I'm glad you hit on the subject. As I mentioned before, I was under the impression that 9.3:1 to 9.5:1 would be ideal and thus my target. I may shoot for a 9.0:1 to 9.3:1 if I have many piston choices. Thanks for covering this.

I'm going off memory here and I haven't checked but wasn't non-hardened valve seats a 70's and earlier thing? There could be some confusion with the heads I have. If D3VE's are 70's heads then that's not what it has.

I was planning on upgrading the valve springs. Nothing fancy just mainly to replace the old ones. Something mild made by a performance part manufacturer. So I need to look at screw in rocker studs and guide plates. Alright. And I take it the factory rocker arms are fine? I did see a set of factory ratio roller tip rockers but I didn't think they would be necessary for this build.

The heads if staying factory would surely be ported, no doubt about it. I have seen the illustrations of the "humps" in the exhaust ports and they clearly choke it way down. As for larger valves I don't even know what it would cost to go that route. I want to keep it as simple as I can but if I could get a set of aluminum heads for $200-$300 more than the cost of machine work on the factory heads then I would likely go that direction. I need to search harder and get an idea what it's going to cost to have the head work done.

Thank you for the link! A little donation for a bit of knowledge sounds like a fair trade off to me.

 

The earlier heads have the engineering number out on the edge of the heads by the exhaust ports, E6's have them on the bottom of the intake side of the head, overhanging the valley. You have to pull the intake to find it.

 

I'm pretty sure I have E6's then. But I will check once more.

But I'm pretty much dealing with the same heads either way correct? Other than valve seats.

 

Yes, the E6 casting is the same as the D3's as far as porting is concerned.
460's are easy to get good power out of, they key is in porting and cam choice, but, my next build will be an aluminum head stroker with a 4.5" crank, if this one ever dies.
Cam choice is VERY important, many people think bigger is better and this usually ends up with an engine that does run well, but could work better for it's application.

I like my torque in very large helpings, so my next one will not be a screamer, but will be built with the same behavior characteristics in mind as my current engine, just with a whole bunch more power.

 

I cannot find an engineering number in the specified location so it must be equip with E6's.

I have heard time and time again that people get too aggressive on the cam and end up hindering the outcome a bit. So I'm making it a point not to do that.

The 460 is so cool. I'm becoming more and more pleased with it all the time.