Charlie, while the RPM range of the EMC engine is well within the range for a representative street engine, at 375 cu in the displacement is not. To run a 375 inch engine to even 6500 at power levels that will make a respectable showing at the contest takes CFM levels higher than 275, but to date that is the limit. Unfortunately, increasing air flow to that level required significantly enlarging the ports. Larger ports on a lower compression, smaller displacement engine will hurt power for street use. Bigger ports = lower velocity in the port. Port velocity is critical. It can be too high or too low.

Grizzly, I have built engines with a fairly standard short block and added performance parts like cam, intake, ignition, better exhaust ect. This can have good results within limits and not break the bank. A reasonable redline must be kept or the whole thing may be short lived. In that regard I agree with you. Some guys spend money needlessly. If you are building a 312 for a 57 T-Bird that will only be used for parades and Sunday cruises you probably don't need forged pistons, billet flywheel, head studs.

I am not familiar with BT rods. Don't know of any rods that will fit a Y-Block that can be purchased for the core value of 312 rods.

Why did you pay $1400 for 2 connecting rods? This seems to reinforce the "More speed costs more money" frame of mind.

If you are saying that taking the cheap way out can end up costing you more money in the end I agree whole heartedly.

http://ford-y-block.com 

20 miles east of San Diego, 20 miles north of Mexico

I get what you're saying. And the heads were ported with the engine masters in mind where the test range will be 2500-6500. That's not out of line for a stout street engine in my opinion.


Lawrenceville, GA

I appreciate what John and Ted are doing with the aluminium head. We are getting lots of information and some testing. Getting the full picture sometimes needs a prod or pushing for further information. But given how much of their own time these guys are putting in it’s not surprising that there is not the time to get absolutely everything out of them.

I had asked about using the race heads on the test mule for a number of reasons. The first tests showed “proof of concept” the heads showed improvements across the rev range on a typical engine with minor modifications. Scientifically the test showed that the old heads formed a restriction across the range when compared to the new.

With the information that only the race engine was to be tested with the ported heads. I asked if they could be tested on the “mule”. Thinking that even if the lower end showed a drop in performance we’d have a parameter or an indication of what won’t work. Often the best indicators are when something doesn’t work. If ported heads did work at low RPM the bar would have been raised.

The Y block should be able to support a head that have good flow because of piston velocity. A longer stroke compared to other engines of similar capacity should support better flow. High piston velocity provides better VE and higher torque at low RPM because of the ram effect.

Given that a 341cu/i is a possible street engine. About 10% larger than standard. Is it too much to expect that you would want a 10% increase in flow?

I understand the level of porting but we are in a development stage and looking for parameters by finding extremes.

Grizzly (Aussie Mainline)

 

"Speed costs how fast do you want to go". Rubbish.

 

Method 1. Ok I decide to rebuild my 312.  I decide that it will just be rebored and not interfered with in terms of capacity. I could (should) have my rods resized but instead I buy a set of BT rods and sell my old 312 rods on ebay. I can have a set of performance rods at little or no cost. Especially compared to what I needed to outlay to recon.

 

Method 2. I decide to save some cash on a rebuild and go with someone that says that can do it at less than the bloke down the road. Or I get talked out of performance component because “Speed cost” “just how fast do you want to go?” I have an engine failure. Or because of the restriction the part I saved on restricts me from what I wanted in the first place. This costs me a second rebuild or sell and move on.

 

Informing myself by asking questions and finding and realizing limitations builds a better engine and saves as it eliminates the need for a second rebuild because the limitation were not realized in the first place. Do as good as you can first up and never have to look back

 

Method 3.  I read a great internet article on performance parts and horsepower robbing components. The guy in question rebuilt a 302 using H beam rods, light pistons, moly push rods etc, to realize a 10% gain in performance without changing the parameters of the engine. 10%. There would be a saving in fuel costs and this engine would last longer. Performance parts that are often considered strengthening or reliability improvements can be also considered performance parts. If you used Ted’s test mule with alloy heads and added these parts to gain another 10% how sweet would that be? There is bang for buck in these components. Cost savings in engine life and fuel can be considered.

 

Method 4. The other end of the spectrum. I have a unlimited budget I want a Y block that delivers a certified dyno tested 1000hp and have it so streetable that my wife can drive it to church on Sunday.  “Speed cost, just how fast do you want to go?” indicates that with money you can go faster and faster and have just what you want. Impossible as there are limitations.

 

I have had experience with most of the above examples including both of the examples in method 2.  Both Mechanic’s (I use the term loosely) favorite statement was “Speed cost, just how fast do you want to go?”

 

Lastly my first passion is motorcycling I have three Moto Guzzi. If you think costs are high for a reasonably common 8V try buying stuff for an obscure Italian V twin. I bought Carillo rods. A set (pair) $1400 the last standard OEM cast piston I bough was almost $500.  When things go bust on a motorcycle you don’t necessarily quietly pull over to the side of the road.

 

I thought you guy's lived in the USA where free thought, free expression and justice for all prevailed. 

Grizzly (Aussie Mainline)

A friend of mine bought one of the first Boss 302s and that thing was a real monster.It was not really a street car.The only thing it was good at was going around curves.That wasn't much use in Central Illinois.No curves.

 

Paul,

Boonville,MO

A friend had a Boss 302, ordered from the factory with the 4.30 (I believe). He had a 5 something ring and pinion installed before taking it home. It needed a lot of gear. As stated no low end torque.

At the same time I ordered a 70 Torino GT sports roof with the 351 C 4V. 3.00 rear axle air and so on. The Boss 302 was a 13 second car. Running off with him he could open a car length off the line, then the Torino would hold the position, passing him (after the 1/4) as he ran out of revs. The big port heads worked OK on the Torino but they were NOT economical. I never did check the mileage on this one as I knew i would not like it. I would guess 12-14 on a trip. These heads were not a good design, poor exaust ports, sewer intakes. It seemed as a different school of thought took over head design in this era,taking a turn from the smaller port design of the Y and FE. This school of thought probably was first seen in the tunnel port FE's. Understanding quality of airflow as well as quantity has taken huge steps. John has done a super job on the new heads. This is shown by the horspower, well above predictions, and fuel flow observations by Ted on the Dyno.

We need to think a 400 Hp Y that is very streetable can become common place. The short block is not the contributer to horsepower that the heads, intake, carb, and cam are.   

The Boss 302 was only rated at 290hp. So in reality, it was probably 320ish and the 351 was only rated at 330hp. In the January edition of hot Rod Magazine, a Boss 351 was built to factory specs and it produced somewhere around 384hp @ 6100rpm.

It is not difficult to build a Y to that level AND have favorable street characteristics. If you want Boss power levels out of your Y, it is absolutely possible - and certainly will not require that the new heads be ported.

Speed does cost money. If it didn't, I'd have a 1500 horse Y in my truck one way or another. It's not just a mechanic who doesn't want to or is not able to do the job. To really build an engine is a lot of work and a lot of time.



Other than the optional cam, the Boss cam specs don't look all that radical and seem to fall inline with the windsor performance cams. They are certainly bigger than your standard street motor.



http://home.comcast.net/~jelerath/mustang/Specs/cams-fr.html



I don't know how reliable that info is but if correct, it seems that the heads were simply the wrong choice for a street car.



Lawrenceville, GA

John, well said!

John - "The Hoosier Hurricane"

Grizzly, although I've never driven one, by all accounts I've ever read the first year Boss 302's were a crap street engine. They made NO low rpm power and only ran at the top end of the RPM range. Ford downsized the intake valves and made the power more usable in the 2nd year of production.

If someone wants to duplicate the performance of a Boss 302 in a Y-Block you could max port a set of the new heads and put them on a 272 (BOSS-Y or Y-Boss ?). Now to really duplicate a Boss302 you would also need to over cam the thing to death, as the Bosses were. The cam would not run below 4500rpm even in a 351.

The factory tech in 1970 wasn't all that advanced. Ford didn't understand port velocity or chamber shape. In the 1990's there was a hugh market in the US for Australian 302 Cleveland heads because the 4bbl US Cleveland heads had too large intake ports and the 2bbl heads had a horrible, detonation prone chamber.

Making power doesn't just mean big ports, big carb, big cam. Also, street power is totally different from dragstrip power.

When I quote an engine job I give people a base price and tell them "every time you say I want the price goes up". Now if you know where to get parts for free you might be able to build a better engine at no additional cost. I have not yet figured out how to install forged pistons for the same price as cast, or how supply aftermarket rods at the same cost as re-using the originals. Last time I ordered from ARP they wanted a lot of money for their fasteners. In short, the more power and RPM you try to wring out of an engine the better the parts need to be in the engine if you want it to live. Higher RPM=Better parts=More money!

I'll bite my tongue now

http://ford-y-block.com 

20 miles east of San Diego, 20 miles north of Mexico

There's only one way to conclude this. Grizzly, get the new heads, have them ported, and let us know how it turns out. Even the most educated people are wrong sometimes. There's only one way to find out.


Lawrenceville, GA