A little more Horsepower

[RodKnock]

Originally Posted by blykins

He is indeed a salesman, but there is more to it than the flow numbers. For a high performance street application, you can't beat AFR head performance.

When you can compare two heads and the flow numbers are the same, but one head has a smaller port volume, you know something is right. This also helps on flow velocity, which in turn gives good street performance.

I think the AFR's are great heads and I owned a pair on a previous car. However, I would not ignore and/or discount the offerings from Brodix. They also make an excellent head.

[patrickt]

I want to see the dyno numbers -- I bet the numbers are lower than he's been led to believe.

[fastd]

I was also talking to a Tech support guy at Ford Racing. His advice was to port the heads, add a little lift to the cam, maybe try a different manifold and evaluate at that point.

[blykins]

Let me give you some advice.

Don't listen to anyone on a tech support line.

Take advice from engine builders that use the parts, build the engines, and put them on dynos.

You can call Comp Cams and ask for cam advice. Then you can call back, get another guy on the line, and they'll recommend something totally different. Most of these guys are bench racers and are paid to answer the phones and look in books.

Rodknock, you're absolutely right....AFR, Brodix, Trick Flow....they're all really good heads and are what most builders prefer to use to make big power.

[Tommy]

Earlier on, someone suggested you let him run potential HP/torque numbers through his dyno software. If you're going to do this thing piecemeal rather than as a complete package, that is the best way to go IMHO. That will come closer to telling you how one specific change is likely to change your existing engine than any number of salesmen or on-line advice givers such as me. Dyno software is not perfect, but it's far better than some saleman's WAG intended to help sell his product.

[fastd]

From a different angle: what do you guys think about Webers? What else would I need to if I added Webers - cam? heads? other? What size Webers are right?

What do you think would do to hp and torque numbers?

[Rare Iron]

Q: What kind of mufflers U running? If you are running "stock" type Cobra sidepipe mufflers (which will have under a 2" flowpath), you are losing major HP on that alone. You could be losing in the area of 40-80 HP.

[vector1]

he didn't say anything about the gearing, shifting, etc. so you have to figure that is on the good side.

hp per dollar spent? have to be cubic inches. you're talking about a weber setup so you must have the wherewithal to do some mechanical work. the heads are probably not too bad along the lines of 200cc jobs. it's getting on to be winter time also so you have some time to do some work.

you could buy a 4.10 stroke shortblock from kc with the appropriate cam and for around $2600-3000 plus shipping have a 418, buy some gaskets and fluids and help of friends and use your heads and peripherals and you'd have all the grunt you need. while you're at it put a lightweight clutch/flywheel in for little to nothing. resale would be good with a kc shortblock also, jmo. later if you want bigger heads etc. you could work on that. you start playing with the little stuff and you'll nickle and dime yourself to death and have spent the money you could have used on a shortblock and clutch/flywheel assembly easily, and still not have as much power.

an aside: this information is worth about as much as you paid for it.

[fastd]

Follow up: Guys, thanks again for your comments. I was wondering if I could ask for your collective opinions yet again...

I finally have some dyno numbers: best run was 314 hp at 6150 rpm and 296 torque at 4900;average run was about 301 hp at 6000 and 290 hp at 4000 rpm.

Shop recommended I switch to a 4150 Holley Double Pumper 650 cfm (currently running a 4160 Holley Single Pump 750 cfm) because they are having trouble balancing air/fuel at the high and low ends and the secondaries don't seem to be kicking in quite right; seems too lean above 4000 rpm; tried bigger jets (started at 72, moved to 74, then 76) but not getting better, air/fuel still over 14 at higher rpms. Replaced power value and that didn't seem to help too much (old one was functional but "weak").
Separately, also recommending replacing undercar exhaust and muffler with 3" exhaust with muffler that exits in front of rear wheels.
How does their advice sound to you all?
Regards.

[Three Peaks]

Before you spend a bunch of money on "stuff" you may or may not need, try to decide what you are looking for - what you want to end up with and start with a plan. The important thing to remember when building and engine is to match the parts to get the required result. A bigger cam won't do you any good if your intake isn't capable of flowing the required air. Also, if your exhaust is restricting your engine, you'll hit a brick wall with hp no matter what you throw on the engine for gains.

If you are looking for around 450-500 hp, you can get there with a set of Vic. Jr. heads, a comp HR 282 or 294 cam, an Edelbrock Air Gap intake, a 393 stroker kit, your present 750 Holley, and a free flowing exhaust. And the cost would be less than the weber set up, I'm pretty sure. Very streetable, easy to build, none of the Weber tuning issues.

Your last post sounds like the tuner is just trying to get it "cleaned up" so it will run smooth with the components you have now. If the horsepower you have now is enough for you, this is probably a good plan. But, if you are looking for a good jump in horsepower, his recommendations really won't get you there.

Just my 2.5 cent's worth....

Bob

[fastd]

Three peaks,

Thanks for your input. I think you are right; my tuner is doing what I ask - at this point he is working on getting to "run right". It looks like I might be able to add 30-40 hp as a result of the carb and the exhaust; in addition, in term of adding adding hp in the future, I will always need a more efficient exhaust, and the double pumper seems like a better option than the 750 single pump if jetted properly.

I will see what it feels like after these changes, and decide if I want to keep going with cams and heads in the future.

[patrickt]

Originally Posted by fastd

I will see what it feels like after these changes, and decide if I want to keep going with cams and heads in the future.

That's a decent plan. The exhaust could make quite a difference.

[RodKnock]

Originally Posted by fastd

How does their advice sound to you all?

Pick your exhaust wisely. Free flowing usually means louder.

[fastd]

RodKnock,
I know what you mean; also, it's very difficult to undo your muffler once it is installed; do you have any recommendations/ideas?

Fastd

[RodKnock]

I was steered towards Hushpower, which was bought by Flowmaster and is now a separate division of Flowmaster. They're definitely quieter than the typical S/C sidepipes, but I cannot verify their claim that they're better flowing/less restrictive and quieter.

[fastd]

RodKnock,
Thanks. Based on your engine specs, I am guessing you have no hp or torque issues.

For me, I hope to pick up 10-20 hp from the stock ERA under car exhaust. I'll try to get it dynoed right after they change the exhaust, before the carb change. It's great standing there watching your number come across the dyno on the big screen. Good stuff.

[Stentor]

Originally Posted by fastd

RodKnock,
Thanks. Based on your engine specs, I am guessing you have no hp or torque issues.

For me, I hope to pick up 10-20 hp from the stock ERA under car exhaust. I'll try to get it dynoed right after they change the exhaust, before the carb change. It's great standing there watching your number come across the dyno on the big screen. Good stuff.

Fastd,

Do you have a dyno shop you use in the Triangle area?

[fastd]

Stentor,

I am going to DG Performance in Franklinton, NC (2126 Pocomoke Road); about 20-25 minutes north of Wake Forest on Route 96. They have had my car for 2 days; I spent most of those 2 days just hanging out in their shop; will probably be there tomorrow as they fab the exhaust and install my 650 double pumper.

Nice bunch of guys - Doug is the owner; really interested in getting it right; don't feel rushed or sold to. Willing to talk about anything you want.

[DAVID GAGNARD]

Just my .02 cents on the subject, and it's worth exactly that........so here goes..........

I think he is dead on with a 650 DP... I've used at least 6 different carbs on my 350hp, 351-W in my 65 Fastback (ranging from 600cfm to 770 cfm) and the best results were with a very old, third hand Holley 600 DP I rebuilt.... I had a custom built Holley 750 built by someone that is nationally know and it was without a doubt the worst peice of junk I ever spent the better part of 500 bucks for, it is now the most expensive paper weight I'll ever own!!!!!!!!!!!!!!!!!!!!!!!! all but ruined my motor, but that's for another thread some day........

Depending on your present exhaust, you could easily gain 30 to 50 hp with an exhaust matched to your present motor........

All total, with a carb change and exhaust, 50hp would not be out of the question and should be easy to get........

I've seen one small block stroker (420 cu in chevy) gain 55hp on the dyno by changing carb/carb spacers/timing only!!!!!!!!!!!!!!!!!!

Getting more out of your motor should not be a problem and only the dyno time will tell, seat of the pants doesn't always tell the truth............

Sounds like you have a knowledgeable dyno guy willing to work with you, use him and chances are he'll get the most out of your engine for the least amount of money right now.......

314hp at the wheels would come out to around 370hp or so at the crank and for your set-up, that ain't bad, IMHO of course......Better exhaust/better carb, some tuning and you could easily have 400hp or more, and while those numbers are not earth shattering, there are pretty stout for a 351-W that you can cruise around town everyday with......and if your car will hook-up the rear tires, you'll outrun 95% of anything you come up against on the street..........

David

[fastd]

David,

Thanks.

I am hoping for good things from the exhaust upgrade; I currently have the ERA undercar exhaust all the way through the rear wheel wells. I post results when I get them - hopefully tomorrow.

Also, thanks for your input regarding the 650 DP...