"treatments" for my Cobra..
 

The only "treatments" my Cobra likes is on occasion, when I beat the snot out of it, it seems to really like it. I know I thoroughly enjoy it!

if I read your original post correctly you have a 302 ci motor (5.0 liter). what modifications are you envisioning to get that 400 HP @ the flywheel? Knowing that might help us point out what engine coatings would be most beneficial. The simple route would be a 331 stroker & quality aluminum heads like AFR 165's or 185's, (or whatever brand you prefer). Nothing wrong with a forged crankshaft either, but I don't think you need one with a 6,500 rpm redline.

Z.

You've hit the combo right on the head....although I had thought about a 347 stroker, I've decided to go with the 331 instead. Right now I'm planning on using AFR heads, not quite sure about 165's vs 185's yet, but that is the route planned--I had considered the 185's, but want to maintain good flow velocity in the intake runners and with only 331 CID, I think the 165's would be better. While I'm running a Performer intake with an Edelbrock carb right now, plans also include switching to a Performer Air Gap/Holley combo (probably in the 600 CFM range, most likely a double pumper with a manual choke). The car already has a lot of Mallory components (electric fuel pump, Unilite distributor/coil) and it spins quite nicely already.

In the interest of longevity I had pretty much decided to go with a forged crank/con rod set.

Probably an aluminum flywheel, if that makes any difference...I don't mind giving it a few RPMs to get it going from a standing start, sure do like how quickly a well-built small block will rev with an aluminum flywheel.

SOME DAY I really want to build a Clevor, but for now I'm going with Windsor heads so I don't have to change out the sidepipes, etc....not to mention the issues getting custom pistons/head work for the "combo". Plenty of time for playing with the Clevor idea later, right now I just want to bump up the acceleration a bit and I'm sure a Windsor will work just fine.

Intended use is probably 95% street use, a decent part of which will be highway use....occasional 1/4 mile blasts just for fun.

Right now I plan on using the well-seasoned factory block that is in the car already, but I am well aware of the problems with splitting 5.0 blocks with excess horsepower.

I will probably have one of the engine builders who posts regularly on the forum build the long block for me and will rely on the builder for the cam choice.

Ask away, folks....I'm open to all suggestions at this point!!

Cheers from Dugly :cool:

I wouldn't spend the extra money on a forged crankshaft. It's very unnecessary for 400 flywheel horsepower. Definitely go with forged rods, I-beams are perfectly fine. I do some 7.50 1/8th mile class drag race engines and use the Scat cast crankshafts with Scat forged I-beam rods. It's a good combination.

I would also go with the AFR 165cc heads and match it to a nice hydraulic roller cam. Top it off with an RPM Air Gap intake and you'll have your 400hp pretty easily.

At 400hp, I would install ARP main studs in the block. No need for a main girdle at that power level.

An aluminum flywheel will keep some weight off the back of the crankshaft, but IMO it will also decrease the life of your clutch. I've had both steel and aluminum flywheels in the same car (my own Cobra) and could tell that I had to slip the clutch a little more to get rolling with the light flywheel.

If you're interested in a long block, I would appreciate the opportunity to quote this for you. I do more SBF's than anything else (street and race both) and can talk at length with you about options.

BTW,

If you're wanting to spin to 6500, you can do it with a hydraulic roller...that will save you from having to run with the risks of solid roller lifters. Longevity and a solid roller really don't go hand in hand. Spring pressures have to be checked occasionally (depending on the cam grind), lifters have to be R&R'd every 10000 miles or so, etc.

The glyptal style paint in OE castings is simply to prevent oil leakage through any casting pores. Cheap and simple way to avoid issues. Beyond the skirt coating the rest of the various "treatments" will serve to increase speed through extensive wallet lightening capabilities. At the 400 HP level you should simply concentrate on good ring seal, good machining, quality name brand parts, and good assembly practices.

"when I beat the snot out of it,"
 

Tim, this must have a back story to it, wanna tell us? tin-man

Must say; agree with Barry.

Although, for competition use, thermal/ ceramic coating to pistons ++ might be a good idea, but any conclusive "proof" of this I have not found.

Coated ("teflon") piston skirts; no, no. Engine treatments: Maybe a strict no to this as well, even how much they say it will cling to the metal & make it run cooler or whatever.

At 400 Hp you won't need a forged crank, neither a solid roller. If I were to choose a setup for a 400 Hp street/ weekend racer, I would go hydraulic roller, or maybe solid flat.
I have "felt" the frustration of going in a line from the pits with engine very warm and idling- getting nervous of those rollers to fail...

I think what most people miss , is that the engine component coatings by themselves generally do not make more power . A friend of mine used to be an engine builder for several NASCAR teams some years ago .... I got to see what was done to some of the engines and , more importantly , why .
The coatings allow you to do other mods that will increase power ... for example , if you treat the piston skirts ( no teflon ) , it allows the tolerances to be tightened up on the piston to wall . This in turn means the piston doesn`t rock in the bore as much and the ring seal is a little better . Is it a tremendous amount of power increase ???? No , but in the top levels of the sport ... every little bit helps . Another example is coating the valve springs to reduce friction between the inner and outer .... makes them run a little bit cooler and keep the tension more consistent and live longer . Coating the tops of the piston helps reduce heat transfer and keeps it in the combustion chamber ... it also reduces carbon buildup and keeps things constant .
They also coat the counterweights of the cranks with an oil shedding coating to reduce the parasitic drag on the crank from the oil .... and you wouldn`t believe the amount of time that has been spent on the shape of the counterweights ( Hint ... what shape is a rain drop ? ) .
Main and rod bearings are also coated ... doesn`t add hp as much as it is insurance that if the oil film breaks down momentarily , you don`t lose an engine ..... and on and on .
On my engine , I have the mains and rod bearings coated and the piston skirts .... not for power , but insurance and longer life .
Ballpark to do an entire engine used to be in the $500 to $800 range .
Coatings aren`t just for engines ... I have seen as many as 15 center sections/housings in my friend`s shop for an oil shedding coating on the inside ... again , it allows them to do something else that adds hp . They also coat the ring gear and pinion ... for reliability, not power .
If you have your heart set on getting some coatings , do the bearings , valve springs and ring gear and pinion ..... it will be a reliability advantage .

Piston speed in feet per minute is what limits what RPM you can rev to. The formula for piston speed is:

RPM * Stroke (in inches) * .166

In the case of a 5.0L engine the stroke is 3" (someone correct me on this if I'm wrong):

6500 * 3.0" * .166 = 3237 feet per minute.

In general an engine from that era with stock internals redline will be set at any piston speed between 2 - 3000 feet per minute.

An engine with good quality aftermarket parts (specifically the connecting rods and rod bolts) will rev to between 3 - 4000 feet per minute.

High performance and racing engines in which long term durability is not important will be between 4 - 5000 feet per minute.

If you had good internals in that engine you could easily rev it to 4000 feet per minute and have the engine live a reasonable amount of time. This would correspond to 8000 rpm.

Of course to do this you will have to run correspondingly high quality valvetrain parts and stiff springs to allow it to rev this high.

As far as 'treatments' I don't necessarily think they are necessary on a street engine but if I were to go with anything it would be a low friction coating on the piston.

Ceramic coatings on the top of the piston should be paired to ceramic coating of the combustion chamber in order for it to be effective. However the gain on a street engine may not make it worth it.

You should buy a good forged crank, it may be hardened by nitriding or it may be induction hardened.