eZ

I built my motor myself and it was my first motor build. about 2500 for the complete all forged 347 short block. about 2500 in aluminum heads including machining and componets. easily another 5k in componets...cam, lifter, headers, intake, carb, oil pan/pump, bolts gaskets etc. etc. dynoed at 353 rwhp so about 420ish. probably a little room left once I get the right headers on. the ports dont match at all right now so maybe another 10 hp.

Rule of thumb when building a motor:

FAST, CHEAP, RELIABLE, .... Pick two

001mustang

i forgot about that ol rule of thumb...it does ring true

Dennis Marks

Thanks. So you have around $10,000 in your engine building it yourself? I really don't want to go there. What did you do to your frame to handle this hp?

OCHOHILL

Your build is very similar to a Fb I am building now. I have the luxury of using a 66 coupe as a test mule. At one point in the mule I had a T5 with 3.89, trac loc and a used HO motor with an air gap and 650 dp. The mule has wilwood brakes and basic suspension mods. The car was a lot of fun. I would guess hp at the crank at 270ish. Just a guess. I thought I wanted the 400hp motor for a similar setup.

Then I drove an 05 mustang with a supercharger with about 425 at the crank. I am not sure I want that kind of power in a classic without some serious modifications. The 65/6 are at a bit of disadvantage because of the tire size.

So, the end decision for the FB is this:

9" rear with the 3.89's-way too much fun can't let that go
T56
a low dollar budget engine I put together on the cheap making around 360ish at the crank

I figure once I get the car finished and the chassis suspension figured out, I can go for more HP if I feel I need it.

Good luck on your build. Sounds like you are doing your homework now. I strongly believe in research. It can save a lot of money.

eZ

Subframe connectors, monte carlo bar, export brace, cross members, 4 link in rear, cage coming soon.

67mustang302

GM's LS7 is a pushrod engine with hydraulic roller lifters and it has the same 7k rpm redline as the new 5.0. Yes, OHC valvetrains are substantially lighter, but OHC valvetrains due to the nature of the actuation also accelerate valves quite a bit more rapidly(one of the reasons they breathe better). Remember it's all about inertia, one half mass times velocity squared. While inertia increases linearly with mass, it increases exponentially with velocity. The more rpm you turn and the more aggressively the valve is actuated(more aggressive cam profile) the more inertia you have to account for from an exponential standpoint. An aggressively tuned high rpm OHC engine like a Ferrari has nearly as much or perhaps more loading in the valvetrain than a lower rpm pushrod engine does. The main advantage of OHC though is be eliminating the pushrod and using several smaller valves, the valvetrain is much more STABLE. And OHC setup stays reliable AND with consistent timing where a pushrod setup loses valve timing(costing power) and flies apart sooner.

As far as a solid roller making more power than hydraulic, of course it will. It has a more aggressive profile. Hydraulic is designed to be maintenance free and reliable across a wide range of operating conditions, but it gives up power to do it. It's not uncommon for guys running solid roller setups on the street to break the valvetrain though.....putting around like normal with an engine that's not really hot from being flogged there's more clearance, valvetrain starts banging around. The solid roller profiles for street use that are easy on the valvetrain give up a chunk of the lobe profile aggressiveness to gain reliability. So the hydraulic vs solid decision in a street profile comes down to whether you want a bit more power or something that's maintenance free.

For someone like me that lives in an area where I see temps as low as 0* F in the winter and over 110* F in the summer, solid is highly questionable. Starting the engine stone cold in the winter vs running at full power in the summer is going to generate a huge thermal expansion range that could cause reliability issues with the valvetrain banging around when cold, or valves not totally seating when hot. And I don't feel like having to mess with valve lash settings throughout the year. Hydraulic is set it and forget it.

Dennis Marks

Trying to drop back and punt this time. My grand standing before I knew the play got me in a lot of trouble. How do you plan on getting 350 + hp cheap? Good advice, Thanks

001mustang

you'll likely spin roughly 5500-6500rpms to exceed 350HP; you'll still need some decent hardware.

65fastbackman

I have a 245/45/17 tire in the rear and a 215/45/17 in the front, tires are Goodyear eagle f1 gs-d3's, 4 wheel disc brakes, traction bars, 1 1/8" front sway bar and 1" rear sway bar, kyb gas-a-just shocks, lowered coil springs and 4 1/2 leaf leaf springs. With all of that stuff my fastback handles like a go cart, lots of power and you take a turn and feel no body roll, and how much bigger for a tire do you want to go? I would say a 245/45/17 is a fairly wide tire to get plenty of grip, hands down better than what they came from the factory with. The 351w weighs roughly 60 pounds more than a 289/302, with aluminum heads i'm thinking probably the same as a 289/302 with stock heads or maybe a little less? might as well get the 351w, do some inexpensive suspension upgrades like the ones I did and call it good. I'm thinking about doing sub-frame connectors, you might want to think about doing the same... but I don't think the 65/66 has a disadvantage at all, other than having a smaller engine bay, but then again I don't think I would want bigger than a 351w... in a mustang at least

Dennis Marks

I would not put anything bigger than a 351 in either. To tell my age, back in 1966, I had a friend who had a real 1965, 289 HP that Holman Moody had rebuilt for him. Even with traction bars, it took forever to quit burning the tires off and start going. Of course that was 45 years ago and technology has greatly improved. Being out of building cars for 40 + years (but I have never lost my need for speed or the excitement to hear the lope of a good cam) makes things very difficult for me. I don't remember the Wright brothers, but I do remember the first space shuttle, Elvis and the Beatles on Ed Sullivan so you can see why I am having to learn all over again. This project has been an eye opener and a wake-up call. The garage floor is now hard and cold, and I cannot make myself look like a pretzel to get into certain places. Pulling engines on tree limbs used to be no problem. Neither was laying under a car in the dirt and mud all day. That is why I have had to farm a lot out. Thanks for the info.