408 Stroker Help

[rcmbronc]

Starting to put together parts for my 408 stroker. I have searched and just looking for some additional info.

Looking at some Eagle kits. I am not sure about the hyper pistons. Pretty sure I want forged. What I am wondering is if I should have a forged crank or is the CI ok. Not going to be massive power put should be decent. Anyone have an opinion on crankshafts or other stroker rotating assemblies?

 

[BUCKWILD]

Are you looking at 600+ HP? Supercharger, No2? If not hypereutectic pistons and a cast crank will be fine. if going to shoot for 500 i would recoment a forged crank.

 

[pcf_mark]

Forged pistons give you margin if you tune too close to the edge. If you run less than 9.5:1 compression and stay with a reasonable timing hypereutectic are just fine. Almost every OEM engine even supercharged use hyper. They are lighter, warm up faster, quieter. I have forged in my 5.0 and i can hear the pistons until the engine warms up. If you go to 10:0 it will be less tolerant of bad gas and more likely to knock. Knock is what kill hypereutectics they crack.

Cast cranks are plenty strong - did you ever see a crank fail? RPM kills the bearings because the crank flexes and reduces the clearance then you get accelerated wear. If you are not reving beyond 5,500 rpm I would do cast. If you are going to rev the bottom end go with a forging.

My opinion - a cast crank is fine under 500 hp and a hypereutectic piston is fine if you are conservative on your tune. I used forged pistons because I play a little closer to the edge and sometimes get a crappy tank of gas in the middle of nowhere. Knock can take out a hypereutectic real quick and w/o EFI retarding the knock like OEM you can break them.

 

[Local Boy]

^^^^^ Excellent answer!

Happy Holidays Everyone!

Aloha

 

[Broncobowsher]

Power and usage targets for the engine when complete. Then we can talk.

I lean toward the hyper and cast parts. Unless there is going to be some severe usage that requires more. Modern name brand hyper pistons are pretty solid. Cast cranks have been used for decades and have lived through a lot of HP. I will even do the I-beam rods so long as they are the modern style with cap screws and not nut-and-bolt.

 

[73azbronco]

I'm with broncobowsher, I used hyper Pistons but did opt for the forged crank as the kit cost no more from Scat at the time. However, If I had to do it all over, I'd probably go forged just to be able to do more later on.

 

[rcmbronc]

My thought right now is Forged all the way through. I really am hoping for around 500 hp. I dont want to be afraid to rev the motor if I want to. I always have better piece of mind with better parts. Cast crank really does not bother me but if for some reason I want to boost it then the bottom end will be strong enough.

Truck is a weekend runner mostly with some local crawling. Truck itself is built in pre runner style so rpm can easily happen also if it does go air born the forged crank will be better with the shock load.

Motor will have AFR 185 heads, hydraulic roller. Not sure on induction yet. Either Edelbrock Pr Flo 4 or a custom Holley carb unless someone suggest otherwise.

 

[Broncobowsher]

If you boost it later, you will want different compression ratio to match. So new pistons. Hang those on H-beam rods now. At this point you just about have a new short block.

I find when you try and build like this it's a compromise that doesn't work great. Either build it for boost, or don't.

 

[rcmbronc]

I know. I am leaning towards H beam rods right now also. Not a very expensive upgrade. I understand the compression ration so different pistons or heads. Looks like a forged assembly with H beams and then no worries about that side of it.

 

[pcf_mark]

If you even think you might want boost go with forged pistons no doubt. You can run 6 psi (30-40% increase in power) on 9.5:1 with aluminum heads and EFI if the tune is good and you run 92 octane.

H beams with good bolts are more important than the crankshaft i would spend that $$.

 

[WheelHorse]

The new Coyote runs hypereutectic pistons. I see guys throwing down 600 to the rear tire on the stock rotating assembly; granted the oil squirters help.

In speaking of Windsors, I safely ran 13 lbs of documented boost on my 93 5.0 rotating assem and that had hyper pistons in it. 93 tune; made 445/442 to the rear tire.

 

[Broncobowsher]

And the weak link will be the block. No point in putting extra money beyond the weakest link. So long as everything is capable of the power level.

 

[68ford]

Have you considered a 205 head? Only reason I ask is I see you are hoping for 500hp. Which is easy to achieve but with a 185 head and 408 cubes it will take quite a cam to feed it and definitely be at or above 6000 rpm and cause bottom end to suffer. I learned the hard way 3 weeks ago. I had a 10.4 to 1 438 built. Used almost the best of everything short of a billet crank. I was hoping to hit 600hp. It made 560hp at 5700 and 565 tq at 4600. I am please with those numbers considering I don't have to spin it real high but I thought it would be higher reving considering I have AFR 220s and what I thought was a big solid roller cam. I spent over over 3000 on lifters and rockers arms alone and have a rev limiter set to only 6200 ��

 

[MonsterBIlly]

In my opinion 185 heads are too small. You will have a good torque rating but not as good as it could be. You would be better off with 205 heads.

 

[pcf_mark]

The new Coyote runs hypereutectic pistons. I see guys throwing down 600 to the rear tire on the stock rotating assembly; granted the oil squirters help.

In speaking of Windsors, I safely ran 13 lbs of documented boost on my 93 5.0 rotating assem and that had hyper pistons in it. 93 tune; made 445/442 to the rear tire.

You can make a lot of power with boost and hyper pistons. But you need a really good tune. Once false move and you lose piston crowns and cylinder walls. Forged can take a lot of abuse and not fail.

My OEM CTS-V is making almost 600 crank HP on hyper pistons and 10 lbs of boost and will do it all day long for the next 100k. But that has highly evolved EFI with knock sensors, IAT adjustment, fuel quality sensing (ethanol).

 

[rcmbronc]

I have been thinking about 205 heads or 195. I had ordered the Edelbrock E-205 heads but then I heard a bunch of bad things about them so I decided to go with the AFR 185 heads. Got a great deal on them but may still have to change to something else.

Any suggestions for which heads? Options look like Edelbrock Victor JR 210 and AFR 205. Any experience with either or others?

 

[MonsterBIlly]

Afr or Trickflow. Both are awesome products. If you are wanting to purchase soon, summit usually has specials in trickflow heads this time of year. Here is an awesome 190cc head as an example. The 205 I think would still be better, but the price jumps 200 per head at that point. https://www.summitracing.com/parts/tfs-52515601-c01/overview/make/ford

 

[rcmbronc]

What is the opinion on Edelbrock Victor Jr 210

 

[68ford]

Read several mustang forum threads and they all said the same, the AFR 205 are much better than Victor Jr.

 

[Broncobowsher]

I love how the talk of a stroker tends to grow rapidly. Heads are already getting bigger, cam is probably getting bigger to match as well, boost is now part of the plan. At some point the parts choices will start getting locked down with parts purchased. Until then lets see how big this will get.