Experience with Stroker engines?

[rkl20678]

A Stroker distributor is just 15 miles away, very enticing. I have a 289 kit and am considering the 302W/347 ci or 351W/408 ci. After the kit itself the engine is the next biggest decision. Any experience or opinions in going in this direction? My kit is in transit so I am definitely just starting to mine wisdom and this forum looks like the very best place to do so.

[Jim1855]

All depends on the selected block and then crank, rods and other bits & pieces. Some blocks are better able to take the additional bore and stroke. Some blocks are better able to take the increase in HP. Then those pesky budgets get in the way.

How are you going to use the car? What are your expectations? Have you experienced a 300, 400, 500 HP or more engine in a 2,400# car? It can be an enlightening experience and may very well change your decision.

Is the engine builder a good source? Do they build a good motor? Stand behind it?

Lots to think about.

Jim

[CraigS]

My MkII came w/ a 400hp 351. I built another short block into a 408. I used the same Performer RPM heads but went from a 650 carb to a 750. I chose a mild cam. I told Comp Cams I wanted to be able to drive at 1200 in 5th. The cam was probably too mild, I am sure I gave up some HP but, dang that was a nice 450hp engine for standard driving. I'd do it again in a heartbeat.

[Brandonk603]

A Stroker distributor is just 15 miles away, very enticing. I have a 289 kit and am considering the 302W/347 ci or 351W/408 ci. After the kit itself the engine is the next biggest decision. Any experience or opinions in going in this direction? My kit is in transit so I am definitely just starting to mine wisdom and this forum looks like the very best place to do so.
I’m not sure if you have any interest, but I do have a 408 stroker which is brand new and built up by a local shop in New Hampshire. I’ve been saving to build a coupe and started with the engine build first and just recently found a guy here on the forum that was selling a partially built coupe With a 427 so I decided to go that route instead and going this weekend to pick it up. Very excited and cannot wait but now I have a new engine that I have no use for. It does have a Holley sniper fuel injection system.
Here are the specs and a couple pictures.

[Rebostar]

I had a 1969 351W block I picked up for $250. The machine shop had to bore it to .060 to save the bores. He also trued the deck. I chose the Scat 418 CI Stroker kit which calls for a +.030 over bore. With the +.060 that brings the CI to just a scosh under 426. This is the second 351W I've done this exact mod with. This should bring about 425 to 450 HP with the Edelbrock 205cc heads and Comp Cam. This is way more engine that the MK4 needs, but its what I had laying around. The first engine is in a 47 Merc Coupe. That block came out of my 1970 Mercury Cougar, which now sports a 427 FE. I also did a 331 Scat Stroker to a 302 I found in Vancouver for $200 that will go in my 57 Studebaker Silver Hawk. Already built, run, and broke in on the run stand.
If I had to start from scratch I would do the 302 stroked to 347. With the right cam and heads you can go from 300 to 450 HP depending on your budget and what you plan to do with it. Cruiser or track? Also do you plan to have it built or will you be building it? Big price differance there!

Happy Trails!

203044203045203046203047

[Brandonk603]

203069203069203069

[GoDadGo]

I'm a big fan of Stroked Small Blocks simply because there is no replacement for displacement unless you're going to boost the sucker.
The biggest limiting factors for making good power from any Stroked Engine is that the heads, intake & cam must be up for the task.
As an example my Dark Side MK-4 sports a 383 SBC which makes a healthy 465 HP @ 6,000 and 465 TQ @ 5,200 RPM.
Everything was set up to run between 2,500 and 6,500 RPM; however, I've have the Rev-Limiter set at 6,100 RPM.
In a car that only weighs 2,350 pounds it throws a big punch with an amazing power to weight ratio of 1 to 5.
Because the car is so darn light it can easily cruise at 70 MPH at 1,700 RPM, but it likes 80 MPH better.

Redbone Link:
https://www.factoryfive.com/whats-new/customer-steve-l-graduates-his-mk4-roadster/

Check out this old video done by Hot Rod Magazine from years long past & one Coyote:
https://youtu.be/V96-AQ1FghI

Good Luck & Happy Parts Shopping!

[rkl20678]

I'm a big fan of Stroked Small Blocks simply because there is no replacement for displacement unless you're going to boost the sucker.
The biggest limiting factors for making good power from any Stroked Engine is that the heads, intake & cam must be up to the task.
As an example my Dark Side MK-4 sports a 383 SBC which makes a healthy 465 HP @ 6,000 and 465 TQ @ 5,200 RPM.
In a car that only weighs 2,350 pounds it throws a big punch with an amazing power to weight ratio of 1 to 5.

Redbone Link:
https://www.factoryfive.com/whats-new/customer-steve-l-graduates-his-mk4-roadster/

Check out this old video done by Hot Rod Magazine from years long past & one Coyote:
https://youtu.be/V96-AQ1FghI
Thank you for the link, geez, maybe I better stay under 300 hp…, I don’t want my first drive to be my last drive.

[rkl20678]

I do have interest Brandon. I donÂ’t know all the rules of this forum but it might be easier to discuss the engine via email. Mine is rockhavenva@gmail.com. Thanks for responding. Rich

[rkl20678]

All depends on the selected block and then crank, rods and other bits & pieces. Some blocks are better able to take the additional bore and stroke. Some blocks are better able to take the increase in HP. Then those pesky budgets get in the way.

How are you going to use the car? What are your expectations? Have you experienced a 300, 400, 500 HP or more engine in a 2,400# car? It can be an enlightening experience and may very well change your decision.

Is the engine builder a good source? Do they build a good motor? Stand behind it?

Lots to think about.

Jim

Words of wisdom Jim, I appreciate it.

[rkl20678]

Looking again at the 289 kit it says it can accommodate a 289 or 302. So my talking about a 351 may be a non starter.

[GoDadGo]

Looking again at the 289 kit it says it can accommodate a 289 or 302. So my talking about a 351 may be a non starter.

What about purchasing a 3.25" Stroker Kit for that block?
With a 4.00" bore it equates to 327 cubic inches.
The Rod Angle Ratios is pretty darn good too.
4.030" bore brings it up to 331 cubes.

SCAT 331 Stroker Kit Link:
https://lmr.com/item/SCA-194055/Scat-Mustang-331-Stroker-Kit-82-95-Flat-Top-Piston-I-Beam-Ro?utm_source=google&utm_medium=cpc&adpos=&scid=scplp&sc_intid=&gad_source=1&gclid=CjwKCAjwiaa2BhAiEiwAQBgyHk7ZumNZlW_2dgsXCpDD Ceo1t9yIarm4EPRr6WaHZIQHXLXbipoJOxoCrxoQAvD_BwE

[gbranham]

When I built my MkIII years ago, I used a donor 302 with aftermarket heads, cam, intake, etc. It made about 325FWHP. It was fun, but I outgrew it pretty quickly. I sold it within a few years to move on to other projects. In the 20 years since, I've had several Corvettes, with the most recent being a 2017 Z06 that made about 740FWHP. I loved it! It scared me a bit if I got too crazy. For my MkIV, I was going to go with a Gen3 Coyote, but switched gears. I'm now building a 427Boss stroker, and should be in the 550HP range. It's likely going to be way too much, but I want it that way. I think I'll love the crazy torque at low RPMs, as that's what I had in my 2017 Z06. 203074

[Jeff Kleiner]

What about purchasing a 3.25" Stroker Kit for that block?
With a 4.00" bore it equates to 327 cubic inches.
The Rod Angle Ratios is pretty darn good too.
4.030" bore brings it up to 331 cubes.

SCAT 331 Stroker Kit Link:
https://lmr.com/item/SCA-194055/Scat-Mustang-331-Stroker-Kit-82-95-Flat-Top-Piston-I-Beam-Ro?utm_source=google&utm_medium=cpc&adpos=&scid=scplp&sc_intid=&gad_source=1&gclid=CjwKCAjwiaa2BhAiEiwAQBgyHk7ZumNZlW_2dgsXCpDD Ceo1t9yIarm4EPRr6WaHZIQHXLXbipoJOxoCrxoQAvD_BwE

327/331 strokers are revvers :)

Jeff

[rich grsc]

but still chebbies.

[Jeff Kleiner]

but still chebbies.

I’m talking about stroking a 302 Windsor…if you go to a 3.25” stroke it becomes 327. If it’s bored to 4.030 it = 331.

Jeff

[rich grsc]

When you replies to Go Dad Go, I thought chubby

Oh yes, 331 with stacks. It's the way to go:cool: Remember this day?

203087

[Jim1855]

How about a 4.125" bore and 3.25" stroke? 347ci, spins, and you can run big valve heads. But you need to start with an upgraded block to get the bore.
Jim

[rich grsc]

Yep, a big bore 347. The cu in of a 347, but a shorter stroke for quicker and slightly higher rev's. :o That would be my next engine

[Jeff Kleiner]

When you replies to Go Dad Go, I thought chubby

Oh yes, 331 with stacks. It's the way to go:cool: Remember this day?

203087

I sure do! I think it’s still the best sounding engine I’ve ever had here :cool:

Jeff

[rich grsc]

Thanks Jeff, coming from you that means a lot. After about 10 1/2 months, it's back to a place where I slipped the battery in, let the fuel system prime and she fires right up, and settles down to a nice little lope.

[MPTech]

I ran a slightly modified '93 302 (GT-40P heads, GT-40 EFI & intake, F-cam). This wasn't bad, had it dyno tuned @ 280hp. Many fun miles and cruises!
After about 10 years, it was starting to have issues and I was itching for a few more horses, so I had it bored & stroked and completely rebuilt. The builder dyno'd the 347 at 493 hp and 464 torque! Can't wait to get it back on the street.
For me the original modified 302 was a good fit, because it was "mild" but better than stock and economical to buy at the time of my build. As I got familiar with my roadster and my fun budget recovered, I was able to build a more agressive version of my original SBF.

[john42]

Yep, a big bore 347. The cu in of a 347, but a shorter stroke for quicker and slightly higher rev's. :o That would be my next engine

I have a Ford Racing Boss 347 and absolutely love it.

[weendoggy]

I have a Ford Racing Boss 347 and absolutely love it.

Yep, Big Bore (4.125) SBF. Keep that piston skirt in the bore!

[mrglaeser]

I have a Ford Racing Boss 347 and absolutely love it.

+2 on the ford Racing Boss 347. I have one in a 1969 Mustang for 8 years. Lots of torque and HP. I'm putting another one in the Roadster with a different head and timing combo. The nice thing about the new blocks is they are 4 bolt mains which at least gives me some confidence in the block when you get to the upper 400+ hp range. Add in oiling and cooling improvements and its a good option, even if pricey. I think there are Dart Short blocks with similar specs to the Ford Racing blocks as well.

[rich grsc]

In truth, the Ford block is just a little better than the Dart. The Ford block has a slightly longer piston skirt, giving better piston support

[Fman]

A Stroker distributor is just 15 miles away, very enticing. I have a 289 kit and am considering the 302W/347 ci or 351W/408 ci. After the kit itself the engine is the next biggest decision. Any experience or opinions in going in this direction? My kit is in transit so I am definitely just starting to mine wisdom and this forum looks like the very best place to do so.

Also running a 427 stroker (dart block) PF4 EFI, professionally built by a local engine builder in my area. I can honestly say after 6400 miles of driving now have zero regrets going this direction. There are a few items on my car I would do differently if I built another one but the engine selection is definitely not one of them. 500+HP in these cars is very do-able and I might add kind of fun :cool: especially if the engine is built properly (ie: cam, induction) they are easy to drive with many smiles per gallon. Just about every Backdraft and Superformance Cobra push rod engine build comes with a Roush 427 for a good reason, you rarely see them with a smaller displacement engine.

[Alec]

Also running a 427 stroker (dart block) PF4 EFI, professionally built by a local engine builder in my area. I can honestly say after 6400 miles of driving now have zero regrets going this direction. There are a few items on my car I would do differently if I built another one but the engine selection is definitely not one of them. 500+HP in these cars is very do-able and I might add kind of fun :cool: especially if the engine is built properly (ie: cam, induction) they are easy to drive with many smiles per gallon. Just about every Backdraft and Superformance Cobra push rod engine build comes with a Roush 427 for a good reason, you rarely see them with a smaller displacement engine.

x2!! I have a Mike Forte-built 427ci windsor (boss block, 351w) with Edelbrock PF4 EFI. THe right look, sound, and power. (About 540hp). I'm very happy about 2500 miles/1 year post- graduation. THe 427 badges on the front fenders are telling the truth.

[J R Jones]

All support systems assumed to be adequate (oiling & cooling) the basic limitations to increasing displacement is:

Stroke exceeding safe piston velocity:
Piston velocity is the distance the piston travels in a cylinder divided by the time it takes to travel that distance, which is twice the stroke. Piston speed is the average piston velocity, which is calculated by multiplying the stroke by pi and dividing by 12 to get feet per revolution, then multiplying by the maximum engine speed to get the maximum feet per minute.
Piston Velocity Limits
The average piston speed for racing engines is 4,000 feet per minute, while early superbike engines can reach 4,500 feet per minute. For aircraft engines, 3,000 feet per minute is generally considered a comfortable maximum. Engines that exceed this value have shown reliability issues.

Increased bore diameter challenges combustion flame propagation:
The flame must travel further. The combustion chamber and piston top are the solution to success. Choose your solution carefully.

BTW in Mercury development we built clear plastic heads so that we could high speed film combustion events. Slowed down it looked like a grass or forest fire, not an explosion.
Yeah, plastic, we spun the fixture to the desired speed, turned on the camera, released fuel and sparked the combustion events; there were not many.
jim

[Avalanche325]

I have a 347 and love it. It is putting out 500+ HP, so a little on the aggressive end.

347
Lighter weight - a little
More room for the induction system. You can run a bigger spacer and / or air cleaner.
Cheaper parts - again, just a little.

408
A little more power for the same build type
You might hear bigger journal size. Two sides to that one. Bigger is stronger. Higher bearing speed is bad.

So, I don't think there is that much difference. They are both good.


Like anything, there are kits that are great and kits that are junk. Make sure that you get something reputable. There are some out there with no-name parts. I would stay miles away from those. There is also a lot of 20+ year old stroker info out there about oil consumption, rod angle issues, etc. It was all figured out years ago, but that stuff keeps floating around. I did a DIY kit from Fordstrokers.com. "Kit" for them is a complete custom package to your specs (with guidance) that you assemble yourself. Not sure if they still do DIY kits, or just full builds.

If you want HP from a Windsor, you must use aftermarket heads. The best version, ported, polished, and prayed over stock heads, don't hold a candle to aftermarket heads. I am running Trickflow. They address some of the flame propagation issues mentioned above with their Twisted Wedge design.

Also, do not be afraid to put a big carb on (if you are doing a carb). Strokers can make a lot of HP. Carbs need to be sized for the power, not the CI. Again, lots of outdated Cfm per CI info out there. I am running a 750, again with aftermarket heads and a Victor Jr intake. Feed those ponies.

Good stock blocks are getting hard to come by. A 302 block can be pushed to about 550-600 hp. The majority of 347s are in the 400 - 500 range. Ford racing or DART blocks can handle big power. Funny how after you get used to it, you could always use a little more.

Personally, if I were doing a 289, I would go for the old school factory look in the engine bay.

[rkl20678]

I have a 347 and love it. It is putting out 500+ HP, so a little on the aggressive end.

347
Lighter weight - a little
More room for the induction system. You can run a bigger spacer and / or air cleaner.
Cheaper parts - again, just a little.

408
A little more power for the same build type
You might hear bigger journal size. Two sides to that one. Bigger is stronger. Higher bearing speed is bad.

So, I don't think there is that much difference. They are both good.


Like anything, there are kits that are great and kits that are junk. Make sure that you get something reputable. There are some out there with no-name parts. I would stay miles away from those. There is also a lot of 20+ year old stroker info out there about oil consumption, rod angle issues, etc. It was all figured out years ago, but that stuff keeps floating around. I did a DIY kit from Fordstrokers.com. "Kit" for them is a complete custom package to your specs (with guidance) that you assemble yourself. Not sure if they still do DIY kits, or just full builds.

If you want HP from a Windsor, you must use aftermarket heads. The best version, ported, polished, and prayed over stock heads, don't hold a candle to aftermarket heads. I am running Trickflow. They address some of the flame propagation issues mentioned above with their Twisted Wedge design.

Also, do not be afraid to put a big carb on (if you are doing a carb). Strokers can make a lot of HP. Carbs need to be sized for the power, not the CI. Again, lots of outdated Cfm per CI info out there. I am running a 750, again with aftermarket heads and a Victor Jr intake. Feed those ponies.

Good stock blocks are getting hard to come by. A 302 block can be pushed to about 550-600 hp. The majority of 347s are in the 400 - 500 range. Ford racing or DART blocks can handle big power. Funny how after you get used to it, you could always use a little more.

Personally, if I were doing a 289, I would go for the old school factory look in the engine bay.

Thank you, packed with great info. I am in the learning process, always Jaguars, never US engines so I also have a gap in terms.

[Justin]

So many options. 20 years ago (literally) I had a 363" SBF302. Solid cam. TRS-R heads, EFI, 1 ⅞" headers. 8000rpm and loved it! With a big bore capable block you can go to 460ci. I chose a 4.125x4". Should be good for 550 on the dyno is my quick guess. way too much...fun.

[Doc76]

I ran a slightly modified '93 302 (GT-40P heads, GT-40 EFI & intake, F-cam). This wasn't bad, had it dyno tuned @ 280hp. Many fun miles and cruises!
After about 10 years, it was starting to have issues and I was itching for a few more horses, so I had it bored & stroked and completely rebuilt. The builder dyno'd the 347 at 493 hp and 464 torque! Can't wait to get it back on the street.
For me the original modified 302 was a good fit, because it was "mild" but better than stock and economical to buy at the time of my build. As I got familiar with my roadster and my fun budget recovered, I was able to build a more agressive version of my original SBF.

What did your build sheet look like to achieve that HP #?

[MPTech]

What did your build sheet look like to achieve that HP #?

Fuel Delivery:
• Holley Sniper EFI - w/ Handheld # 550-510
Manifold:
• Edelbrock Victor Jr. Intake Manifold 2921, Aluminum, single plane
Ignition/Distributor:
• Holley Sniper EFI HyperSpark Distributor Kits 565-301K (bronze dist gear)
Block:
• 302ci, 2 bolt main, bored .040 (347 c.i.)
• Bored and honed, Deck block parallel and 90 degrees
• Balance rotating assembly
• Blueprint and dyno engine
Rotating Assembly:
• Eagle Forged Steel crank (internally balanced) 4340
• Eagle Forged 5.4” rods H-Beam, 3.4” stroke CRS5400S3D
• SRP PRO SERIES 347/434 SBF Flat Top pistons 867-271099
• Chromoly pushrods
• Heavy duty roller timing set
Heads:
• AFR - Airflow Research 185cc Renegade Street Aluminum Cylinder Heads 033-1388
• 58cc chamber
• 185cc Intake Ports, 70cc Exhaust Ports
• 100% CNC Ported Combustion Chambers, Exhaust Ports, Intake Ports
• 1.290'' OD Hydraulic Roller Dual Valve Spring
• Comp Cams Ultra Pro Magnum Rocker Arms, Chromoly 1.6 1632-16
Cam Specs:
• Comp Cams Xtreme Energy Camshaft (Hydraulic roller) 35-324-8
• Duration 270/276, Lift .544/.544