Engine Experts... Info. Needed ....

[Denny S.]

I am currently building a 460 Bored .60
over. Yes I know it's not an FE. I have one of those in my Contemporary. This engine is going in a 79 LTD Grocery
Getter... I have decided on Heads, Headers, Gears, CAm, Rockers ETc ETc.
I want to run 11-1 CR, but the engine shop and a friend ( Ford Guy) says OH NO
should stay below 10-1. THe builder that built my 428 ( OLd Ford Guy ) says no problem as long as you keep your cranking pressure down. Performer Intake and at least an 860 CArb. Forged PIstons, Roller Rockers All the Good stuff.
So who's right ? I don't care at all about mileage or the price of fuel... It took a month for this friggen comitee (sp) to try to decide on a cAm and I finally took the bull by the horns and spent a good 45 min. on the phone with Comp. and decided on a split Duration CAm Part # 34-249-4 You can look this grind up on the Comp Page. A little feedback would be nice...

[TomH]

11:1 for a "Grocery Getter?" Where are you going to get gas? I'm surprised that your builder didn't ask about the heads. Aluminum will "buy" you about a point of compression, but at 11:1 you're already "out of the envelope."

It gets cold in PA, so I wouldn't do it, but hey, it's your ride.

[CJ428CJ]

Denny,

Before you decide on a cam, get yourself a copy of the computer simulation software called Dyno2000 (aka, Desktop Dyno). It costs about $40 and it does a wonderful job of helping you compare camshafts in your simulated engine. I've heard of others that have used it and then had their actual engine dynoed and the results were remarkably similar. I wish I had bought it before selecting my cam. I selected a cam for my 428 that the program shows puts out 458HP@5500 and 493 ft-lbs of torque at 4000rpm. Other similar cams I could have selected came in as high as 483hp or 511 ft-lbs of torque. I plan on posting a spreadsheet a little later today showing the results of the 20 or so cams I compared.

Regarding your compression ratio, I think 11-1 is a bit high. I'm not familiar with 460s so I don't know if their prone to preignition, but I'd suggest 10 or maybe 10.5-1 is the most I'd go. Running aluminum heads will help a lot (they don't retain the heat as well as iron heads) and using a long duration cam will allow higher compression ratios (the valves are open longer which prevents the cylinder pressure from getting as high as it would in a short duration cam). I'm running 10.25-1 in my 428 and I'm glad I didn't go any higher.

Chris

[Hotfingrs]

Originally posted by CJ428CJ


using a long duration cam will allow higher compression ratios (the valves are open longer which prevents the cylinder pressure from getting as high as it would in a short duration cam). .

Chris [/b]

This is not true.... my cam has .667 lift, 261@50 and 291 total and has 285 lbs cranking pressure....lobe seperation and overlap all play a part of cranking pressure

[Art]

I think you'd be better off with around 10/1 C.R. and be able to dial in a little more timing.

Too much compression, you may have to retard the timing (to avoid detonation) so much that it would negate the extra point of compression ratio.

Have you considered a stroker? Several good ones out there less than $2K.
I bought a 427W kit from these guys...

[Mr.Fixit]

Grocery getter 9.5-10.0 compression. That will still require premium pump gas, but not race gas. I don't want to do any looking up of cam numbers, but keep the intake duration at .050" lift at less than 115 for that big heavy car with an automatic and low stall converter. You want and need lots of low end torque.

[Denny S.]

If I deck the block and run flat top pistons
with an 80 CC head ( PI Heads) the CR I've been told will be 11-1. My Old guy Ford Builder ( 50 years of Fords) says the 460 has the best flame travel of all and it will run all day on pump gas.. So how do you run this set up using Desk Top Dyno or can somebody run it for me and what numbers do you need ???

[BB427]

What are you going to do with the car????

[trularin]

It sounds like you are fishing for someone to say, "Yes, 11:1 is fine, go ahead."

This old guy. Is he going to buy your gas? Can I get in on this also?

I have to agree with most of these people, 11:1 is a bit steep.

But, hey it's your ride. Why not make it 13:1? NOS? Mixed fuel?

871 or 1271 blower?

Don't take me wrong, I wish you all the success.

Just my $0.02 worth.

BTW, as far as old is concerned, how old is dirt?

[Denny S.]

This will be one of my (besides the cobra) downtown tire smoker play with the kids car. Fuel costs are a non issue.
It won't be taking 300 mile trips to sightsee. When I'm done it will look different ,sound much different and hopefullly burn the tires up in smoke whenever I get the urge. I can drop the CR by not zero decking the block, but I want the most bang for the buck. It will limited to 6000. C-6 Auto.

[Mr.Fixit]

You still want no more than 10:1 compression. period.

For tire smoking fun, a small duration cam is in order. The one you listed will need a 2500 stall converter and at least 3.73 gears to not be a total dog in your combo. Duration At 0.05 232 237 That cam won't come on till after 3000 rpm.

I suggest something more like 34-226-4

Use a vac secondary carb if possibleholley (Holley 850 vac)

[BB427]

The last street 460 I had was .030 over (466) with eagle H beam rods and a set of TRW L2443 forged pistons. They have a very slight tapered dome that does not effect flame travel. In a 72cc head they are around 12-1 depending on gasket thickness and deck height. I have also buit a std. bore 460 and used these same pistons but I milled the dome off for less comp. They are inexpensive pistons and work well in a street engine. I do not care for them in a race engine because of their weight. As far as cranking pressure goes you better have some. A cam with alot of overlap wont like that heavy car and an automatic trans. Put the lift to it and keep the duration down. You could actually drop the compression a little and have a cam ground that builds cyl. pressure and fool the motor into thinking it has more compression. Put a good gear reduction starter on it and go.
You don't need alot of HP you need frame twisting,doors out of adjustment,broken motor mounts torque.

Just an opinion
Good luck

[Denny S.]

I'm planning on 3:77 gears... My question is this now that I"m totally confused. Why is the Comp guy telling me that the cam I listed came on at 1800 . Now which is it 1800 or 3000 ? Theres too many friggen choices and even posting this same question here and on the 385 forum I can never get a consensus.. For some reason my engine guy down south ( Built my 428) says 11-1
all day in a 460 no problem. Then I get guys posting over at the 385 page running even higher CR .. I'm totally confused. I just don't wanna get talked into something by the builder up here
(Does alot of chevy's too.) Because he's used it before and it's his generic pick.
I'm paying for this and not him or my friends. He tried to talk me into KB hyper whatever pistons and my old ford guy says they are junk. My old guy wants forged flat tops. THe guy up here says Oh when you get done it should dyno at around 400 HP. Well the friggen thing stock was rated in 1970 at 365. So I"m spending $4000 in parts to gain 35 HP ??? I f I simply wanted a rehashed 460 I would just buy a rebuild kit and do it myself. What numbers does someone need to run this on desk top dyno ???

[Art]

OK..
Your engine guy just lost a few points in my book...

If you aren't buzzing to 6500RPM or using "spray", the KB pistons are fine... Much quieter than forged, stronger than cast stockers. Price is great!
Mild ported D0VE heads, hydraulic retrofit roller cam, keep the compression under 10.5/1, 11" stall converter, dual plane aftermarket intake, 700DP Holley.....
Torque monster!

[BB427]

Dump the engine guy!!!! If you take a 460 apart and grind "the bump" out of the exhaust port and install a 60.00 hydraulic cam you can make 400+hp all day long. Don't spend alot of money based on the desktop dyno results...its a toy...thats all.

[TomH]

This keeps getting curiouser and curiouser. A 460 with a much milder setup than anything described to this point is going to put out a lot more than 400 HP.

Every answer on the forum is not going to be equivalent to the Oracle at Delphi, so you might want to do some basic homework on engines. Read FRPP's catalogue for a good cheap primer on "out of the box" engines. Search this forum for Venom_S' experience with simutaneous discovery/construction on a High Performance BB engine. With a better BB background, you'll have an easier time organizing/filtering the information.

[CJ428CJ]

Denny,

I disagree with BB427 that Desktop Dyno is just a toy. It undoubtedly makes assumptions and there's no way it'll get you a 100% accurate number but it'll get you a lot closer to your actual horsepower than all the guesstimates on any forum. Engine and cam designers today don't say "I think this will work," build the motor and then put it on a dyno. They model it first using computer modeling. That's what desktop dyno does too. I'd be happy to run some numbers for you. I would need:

1. The compression ratio you want me to plug in.
2. Info on what heads you're running. If you're running the Edelbrocks that's easy. All the data I need is on line and I can pull it up. If you're running something else, I need valve diameters and bench flow data would be great but you probably won't have it if you're using stock heads.
3. You're using the Edelbrock performer manifold right?
4. Exhaust - stock manifold and mufflers, hi-po manifold and mufflers, or headers with mufflers. If headers, what diameter are the pipes?
5. Cam specs but I already found them for your cam grind.

Let me know and I'll run the numbers and tell you what I find.

Chris

[Denny S.]

472 Cubic inches,80 CC police interceptor heads. Lets say 10.5-1
instead of 11. Performer intake, Cast CJ headers. You have the cam gring comp advised. Roller Rockers, Hydraulic lifters
According to both my Ford Guys these
heads with 0 deck and flat tops will equal 11-1. THe Old guy( And he's been building ford drag motors for 50 years)
says thats the ticket. with a 1050 Dominator. THe other engine guy suggested a Quadrajet or Edelbrock. I'm really torn between 70 yr old guy that can recite every ford part number known to man and tell you clearances, pretty much anything I've ever asked him he knows about Fords.. And a more modern engine builder that will build whatever you bring to him. But he does have a very good rep.... It's getting to me, trying to decide who to believe....

[Art]

Originally posted by Denny S.


I'm really torn between 70 yr old guy that can recite every ford part number known to man and tell you clearances, pretty much anything I've ever asked him he knows about Fords.. And a more modern engine builder that will build whatever you bring to him. But he does have a very good rep.... It's getting to me, trying to decide who to believe....

Go with your first instincts.... If you're impressed with the guy and has a good rep..... Well, he's the pro, right?

[CJ428CJ]

Denny,

I plugged the numbers in. I used the edelbrock head flow information since I know nothing about the police interceptor heads. I come up with 400hp@5000rpm and 486ft-lbs@3500rpm. That's with 10.5-1 and hi-po ex manifold. Switching to large tube headers takes it to 454hp@5000rpm and 522ft-lbs@3500. Looks like you might want to invest in some headers.

I'd be happy to plug in other combinations if you'd like.

Chris