357, 393, 408 and C4

[jcb9089]

Debating building a 357, 393 or 408.

Have good 351 roller block that machine shop says can go 4.020
- lightning 351 lower, and 64cc aluminum heads.

Have a newly rebuilt C4 that can handle 400/450HP, 31 spline 411 gears, tom woods drive shaft.

Bronco sees 90% road/10% off road.

I want manageable (for a bronco) throw me back in my seat power, but also concerned I will break drive train if I go to big.

Will a 393 or 408 be too much?

Thanks!

 

[EricLar80]

Nope, it wont be too much. But you may break some parts on occasion.

May as well go 408 since there are more parts available for that setup. Ask me how I know!

 

[jcb9089]

Thanks Eric, I read through your 393W transformation...great thread to pick up a lot of info.

 

[Broncobowsher]

Too much motor said no man ever.

The thing you need to pay attention to is the compression ratio. With 64cc chambers it is real easy to get a lot of compression on a stroker.

I started a thread that got a lot of good feedback over the years. Search 20 questions for stroker owners. You can read up on what they built, what they broke, what they would have done differently. Lots of good data about built up stroker engines used in Broncos.

 

[Bronco Brian]

http://classicbroncos.com/forums/showthread.php?t=196925

 

[jcb9089]

I looked through the stroker questions, good info.

Found an eagle stroker 408 kit at decent price but comes with -22 KB pistons. Machine shop asked that I avoid Kieth Black pistons.

Any recommendations on quality kits that won't hit so hard in the pocket?

 

[Broncobowsher]

Eagle and Scat are the two big names in affordable stroker kits. That is what you will probably find when searching, even if they are rebranded.

What does the builder have against KB pistons? The ones I used in the past looked to be pretty good and didn't have any issues with them for 4 years (when I sold it and lost track).

Which kit were you looking at? guessing from the affordable factor it is the cast crank, I-beam rods and cast hyper pistons. That should be a good kit.

 

[jcb9089]

Builder didn't elaborate, just said he doesn't like working with them. Didn't say I couldn't get them though.

This is a decent priced kit.

http://www.jegs.com/i/Eagle/356/16524020/10002/-1

The Scat kits seem to be a bit more expensive.

 

[Broncobowsher]

http://www.eaglerod.com/index.php?option=com_content&task=view&id=21&Itemid=32

Different piston spec. They show -27.5cc

Standard 28 oz-in so normal 351 damper and flywheel will work. Note that it is not a balanced rotating assembly, it is intended to be balanced with the 28 oz-in parts. They have pre-balanced kits available that comes with a damper and flexplate (or flywheel?)

 

[5001craig]

Have you looked at the Edelbrock stroker kit? That's what I have.

When I went down this road, I decided everything behind the new motor needed upgrading. I went with a nice C4, Atlas 2 (with short 300M output shaft--should've gone HD case version just didn't know then what I know now), 35 spline rear axle and new shafts. I stayed with the 1310 joints but should have upgraded them--it would have been easy as everything was being replaced anyhow. Front shafts are chromoly. Diffs are both Gruzzly and have new Yukon gears.

Oh, and I carry a spare rear drive shaft. Ordered an extra rear just in case. I figure if you buy it you will never need it. Lol

 

[jcb9089]

Good advice...I recently had my 9" upgraded to 31 spline 411 trutrac. Hope that can hold up, it was expensive.

Hoping to keep compression around 9.0-9.5 so can use 87 octane.

I looked at 408 stroker kit from fordstrokers.com but it was about $1600 balanced. Figured the Eagle 16524020 (406) kit might end up being a good kit and cheaper if balanced at the machine shop.

I'll look for edelbrock stroker kits too. Don't want to go cheap but $$ adds up fast.

 

[Broncobowsher]

With aluminum heads and 6,000 foot altitude you can probably bump another half point of compression and still run 87. Unless you are planning on running 85.

 

[jcb9089]

thanks for that tip, good info.

I've read good things about this site. Will call on Monday and come up with a 408 kit balanced.

http://www.adperformance.com/

 

[pcf_mark]

Always go with the biggest engine you can afford. Always.

 

[AZ69EB]

Sometimes cheap stoker kits end up costing more trying to balance them. Talk to your engine builder / machine shop for their recommendations. Determine what you want in regards to hp & tq before you open your wallet. It will save you a lot of time & money. Go luck

 

[AZ69EB]

If you decide to go stroker the Lightning intake is not an optimum choice. The Lightning lower can be ported to handle over 300 cfm, but the Tubular upper or Explorer upper will be the bottleneck. The lightning intake is better suited for the 357W and not stokers. It's all about parts matching to maximize hp & tq.

 

[jcb9089]

Pulled the trigger and ordered 408 kit from fordstrokers.com


Probably should run AFR-185s and edelbrock intake...will need to save up for those as the $$$ is adding up fast.

 

[tirewater]

Ooh congrats. Post some pictures of the engine components when you get them.

 

[AZ69EB]

JCB9089 - Congrats. You just started the snowball rolling. I have a 408 sitting on an engine stand for over a year collecting parts. The wait will be worth it. Good luck

 

[-8]

I really like the GT40 351W Lightning lower intake. I would definitely flow bench it and find the walls with the lowest air speed and weld in wedges to increase air speed. I don't now porting but I have always been curious about the flow bench data of stock ports and what wall of the port has the slowest air speed to begin with. I had my cylinder heads ported professionally and the machineist tig welded shims on the floor and the wall with the slowest air speed and maintained a healthy wall thickness.

I would go with the longer stroke.

The FMX is very strong in stock form and may not need any upgrading aside from the valve body. I also really like the C4.