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351C stroker question??

January 17 2012 at 11:59 AM
Rich  (Login MMUBM5)
Member
from IP address 99.194.201.19

I plan to build a 351C stroker motor. I'm an older, retired Ford mechanic that wants a faster toy. I have a 1972, 4-bolt main block that was just bored to 4.030". I don't want to build an all out race engine, just a good street motor that will be installed in my 1970 Mach 1, 4-speed, 4:30 rear gear. I was thinking a 408 stroker with the stock 4V heads, along with a roller hydraulic cam, would be the way to go for a good street motor. Something that would rev around 6000 RPM. I checked out the internet and called several engine shops/builders that specialize in the 351C. Now I'm confussed. Everyone has a different opinion, from what size stroker kit to install to the type of heads to use. What I thought would be somewhat simple, has become hard, because of a vast amount conflicting opinions. I do know about rod angle and I am concerned about cylinder wall cracking. Some builders say there is a concern and some say not to worry. Some tell me to install hypereutectic pistons, because less clearance is required, better/quieter for a street motor. Some say no way, go forged pistons. I also realize the stock 4V heads won't produce the kind of power the CHI or AFD heads do, but do I need the max HP for the street? With some of these heads you have to use their intakes, which is costly. Also, I could get too much HP and the 1970 Mustang body may not handle this unless frame rail supports are installed. I just want some honest opinions from car owners that have done a 351C stroker and don't have anything they are trying to sell me that influences their advice. I want to build something that works well, that will last and not give me headaches. I do know cheap is not always better. Thanks much.


    
This message has been edited by MMUBM5 from IP address 99.194.201.19 on Jan 17, 2012 12:01 PM


 
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Mike
(Login 70vert)
Member
64.244.192.35

Re: 351C stroker question??

January 17 2012, 12:15 PM 

I haven't finished it yet, but I am working on a 408 stroker with 4V CC iron heads. Mine will also be mild street build with a hydro cam and running on pump gas. I'm shooting for about 10-10.25:1 compression. I bought a stroker kit from CHP. I decided to go to the forged kit just in case I want to go to better heads/cam for more power at a later time. I also like the peace of mind of a forged unit in case something happens like bad gas, stuck throttle, etc. I'm not worried about a little more noise at start up (I probably won't hear it over the exhaust). I had forged pistons in my last 302 build and I drove it in -20 weather middle of winter for several years. No problems at all and I didn't notice any unusual noise from the pistons. People make a big deal about oil consumption with the wrist pin intersecting the oil control ring, but I'm not going to drive this a hundred thousand miles daily commuting. I'll be lucky if I get 3,000 miles a year driving it on nice days. I probably won't wear it out. I'll probably decide I want to upgrade the engine before it ever gets worn out.

I'm a little worried about cracking a cylinder, but I had the block sonic checked and I don't think I should be too worried in a street application. It's not going to spend that much time at max revs. I think rod/stroke ratio is over-blown and a 408 r/s ratio isn't that bad even compared to some production vehicles that typically last over 100,000 miles.

If you plan to drive a ton and live in a always sunny area, maybe keep the r/s ratio down more and keep the wrist pin out of the oil control rings. If you have a 3 month summer like I do and won't be driving it a ton, I wouldn't worry about it.

 
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John
(Login 1972blackmach1)
Member
67.175.138.116

Pistons

January 17 2012, 12:23 PM 

All production supercharged and turbocharged engines come with forged pistons that last as long if not longer than non forged.Zr1 ,AMG, turbo volvo's etc etc..

 
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Rich
(Login MMUBM5)
Member
99.194.201.19

351C stroker questions??

January 17 2012, 4:27 PM 

Sounds like we're doing about the same thing. I just hate to dump $2500.00 or so into a set of aluminum heads so I can get more HP and probably in more trouble. The prices for CHI or AFD were in that price range. I looked at all the other aluminum heads being sold for a Cleveland and there are cheaper sets, but not too many good praises for them. Like you said, the heads can always be changed out later. I live in Northern Illinois and our fun time for old cars is basicly late April to October. I probably won't drive 3000 miles a year either. I would rather put the head money into an A/C unit for the car. Are you doing anything special to your iron heads? I just planned on new seats, guides, valves, springs and whatever else. The R/S ratio on a 408 is not all that bad. I know the cylinder walls on a 351C block are thin and I then when I read a few horror stories about cracked cylinders after they installed a 408 stroker, I started to worry. Who knows how these were driven and what kind of RPM's they saw. I'm keeping the car's original engine as it was. If the stroker breaks, I still have the original to stick back in the car.

 
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Mike
(Login 70vert)
Member
64.244.192.35

Re: 351C stroker questions??

January 18 2012, 11:56 AM 

Yeah sounds like our builds and goals are pretty similar to me too.

The 4V CC heads I have already have some light port work done to them. I took them to my machine shop and they said it looks like whoever did it knew what they were doing. So, I just had the springs checked and shimmed. My heads already had aftermarket 1 piece valves and a good set of double springs in them as well. I thought about putting hardened seats into them but most of the feedback I've seen online is you don't really need hardened seats. I wouldn't run original 2 pc valves, but other than that I wouldn't do too much with 4V CC heads. Just let 'em buck!

I think since you already have the stock stroke 351C and this is your extra motor, you should go for all the cubes. The reason I went to 408 is that I wanted a 7,000 rpm max motor and I think that even 408 cubes won't reach the limits of the 4V CC heads at 7,000 rpm. So to me the way to maximize the performance of the 4V CC heads in my rpm limit is to get the most cubes I can. It would be fun to build a 8,000+ rpm stock stroke 351C, but I think a 408 will be cheaper and easier on parts in the long run.


    
This message has been edited by 70vert from IP address 64.244.192.35 on Jan 18, 2012 11:57 AM


 
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Rich
(Login MMUBM5)
Member
99.194.201.19

351C stroker questions??

January 20 2012, 10:54 AM 

I think the 408 stroker is the way to go. A 393 or 383 would be good too. Just getting the cubes up will help the air flow in the heads. As far as head work, I plan on new SS, one piece valves, new guides, springs, retainers, and I was told to do the seats too. You are right about the seats and your reason for not replacing them, but my heads have been played with before. The seats are low and my mechinist said the valves are sitting too low. I did do a mild port job on these years ago. Mostly removed casting slag and did some exhaust work, trying to enlarge the port. My heads still have the rocker arm pedistals. Crane made a kit years ago, that allowed for better rockers. I should just mill and drill them and go with studs. I was going to stay in the lower 6000 RPM zone, maybe up to 6300. I didn't to rev too high because of the so called cylinder wall stress cracking.

 
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tinman
(Login tinman351)
Moderators
71.57.55.107

4032 vs 2618 alloy

January 17 2012, 1:20 PM 

whoever said Forged and Hypereutectic was probably right, read here...

http://www.carcraft.com/techarticles/ccrp_0810w_mahle_piston_alloy_comparison/index.html

4032 being high silicon probably qualifies it as Hypereutectic alloy, the 2618 probably Hypoeutectic

forged construction, better than cast... best of both worlds?

depends upon the application wink.gif

but a 4.30 rear gear sounds like a lot, with a 26" tire you'll tach 6k at 108 mph

there'll be phantoms, there'll be fires on the road... and the white man dancing

 
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Rich
(Login MMUBM5)
Member
99.194.201.19

351C stroker questions??

January 17 2012, 3:10 PM 

Good article. Thanks. The 4032 piston sounds alot like the hypereutectic type. I called KB Pistons or Keith Black and they told me that they didn't even make a hypereutectic piston that would work with a 408 stroker kit. That's not to say someone else doesn't. The tech guy I spoke with said a hypereutectic piston would be good for at least 500 HP and is a better piston for a street motor that won't see much more than 6000 RPM. They are quieter and last longer, just like the Car Craft article says. And the 4:30 gear, you're right. It may go. I do plan on installing a five speed or Gear Vendors OD unit, but that's another chapter. Thanks.

 
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dion
(Login xdclevo)
Member
202.63.49.193

Re: 4032 vs 2618 alloy

January 17 2012, 3:29 PM 

I wouldn't look too hard into that Car Craft article, as Forged pistons havn't had big expansion/noisy running on cold motors since the old TRW Forged days, and the 2618 have tight piston to bore clearances and are light weight as well. Like stated, only forged pistons are availl off the shelf for a 408 and thats the way to go. The 4032 are listed as Factory replacemnt pistons on the probe site, so you would run them in a basic streeter with the std 351 crank only.

http://www.probeindustries.com/Probe_Domestic_Forged_Pistons_s/10.htm

I have had my 30 thou over, 408 Cleveland running for over 4 years with near 600HP and havn't touched it bar change the oil. When i race, i shift at 7400 rpm and it has been very reliable.

I think the 4V's will peform very close to any of the alloy head offerings out there, just pick the right piston CC to get you compression right. I run the Probe SRS 14213 with a 16CC dish to get my compression where i want it.

Are your 4V open or closed chamber? Are you going to fit good one piece valves and decent reatiners/locks etc?


    
This message has been edited by xdclevo from IP address 202.63.49.193 on Jan 17, 2012 3:31 PM


 
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Brent Lykins, B2 Motorsports
(Login blykins)
74.134.178.200

+1

January 17 2012, 3:42 PM 

Probe (or even Diamond, Mahle, JE, etc.) forged pistons would be a great choice.

Don't worry about excessive clearances like some of the older forged pistons used to run. Forged pistons these days run around .0045-.006" clearance depending on the brand and material. Your cast stuff usually goes at around .0015-.002".

If your block has the correct clearances, you will not hear the forged pistons....I promise.

Brent Lykins
B2 Motorsports, LLC







 
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Rich
(Login MMUBM5)
Member
99.194.201.19

351C Stroker Questions??

January 22 2012, 10:02 AM 

The heads I would be using are stock, 1970, 4V closed chamber with the rocker pedestals. I plan on new SS valves, new quides, new seats (maybe, if the machine shop recommends), new springs, new retainers, machine off the pedestals and some port clean up. I plan to do them right. I even thought about sending them off to a shop that specializes in 351C head work, but don't know if all that is worth it for a street motor. If I stick too much in them, I might as well go aluminum. I live in Northern Illinois where we have lots of E85 fuel. I thought about designing the engine to run on just E85. I'm not sure what compression ratio would be required and how E85 would be using a carburetor, since all modern cars using E85 are EFI. Any ideas?

 
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Brent Lykins, B2 Motorsports
(Login blykins)
74.134.178.200

Another builder's opinion....

January 17 2012, 3:40 PM 

A 408 with the right cam and 4V heads will definitely surprise you. I'd aim for about 500-550 hp, which is certainly do-able with those components.

There are no issues with rod angles (some people get obsessive with that subject), rod ratios, or anything of the like.

As for the rotating assembly, a Scat cast crankshaft, Scat forged I-beam rods, and forged pistons would be the way I would go. For the money, forged pistons are just a couple hundred more than cast and you get a lot nicer piece...in most cases machined to a tighter tolerance, able to run smaller ring packs, etc. You would also have some room to grow if you wanted to ever upgrade to boost/spray.

This shouldn't be a hard choice, but with everything else in the world, everyone has their own opinions...

FWIW, I build Clevelands and have done all of these combinations...



Brent Lykins
B2 Motorsports, LLC







 
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Steve.k
(Login steve.k)
Member
209.91.107.221

408stroker?

January 17 2012, 4:21 PM 

Well we have talked about this a few times on here for sure! What are your reasons for stroker? I think most have come to the consensus that with today's camshafts, carbs and other goodies a 550 - 600 hp c-motor is not that big of a deal even without stroking. If your heart is set on stroker than go for the gusto. I would buy one of the complete Stroker kits offerd from the various builders. The iron heads are very close on power so unless you have a ton of money or no iron heads then yes a new aluminum is the way to go. I myself went to the 400 block based stroker and knowing what I know now(info gained from this site) I would've built a real stout stock stroke Cleveland. It would have been way easier. Good luck in your build. Oh ya the Keith black hyper pistons are of very good quality and I have used them in 550 hp motor with zero issues.


    
This message has been edited by steve.k from IP address 96.30.200.35 on Jan 17, 2012 5:11 PM


 
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Rich
(Login MMUBM5)
Member
99.194.201.19

351C stroker questions??

January 22 2012, 10:20 AM 

Thanks for the info. I just decided the extra cubes would be fun for the street. I bought the 70 Mach 1 new in 1970 and I couldn't get the 428 CJ because of insurance cost. I bought one with the 351C instead. It ran good, but it never had that low end feel the 428 had. I just thought with all the stroker kits and new cams available for the 351C, why not have some fun. The motor I'm building is an extra block I bought. I'm saving the original motor as it was.

 
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bop
(Login hardbopper)
Member
147.239.4.22

good plan

January 22 2012, 2:35 PM 

"The motor I'm building is an extra block I bought. I'm saving the original motor as it was."

b

 
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Rich
(Login MMUBM5)
Member
99.194.201.19

351C stroker questions??

January 22 2012, 10:10 AM 

I am going with forged pistons. No questions! All you guys out there have all said the same thing about piston choices. I appreciate the good info. Thanks.

 
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Joe D. Craine
(Login MsgtJoe)
Member
75.1.90.180

Another option is the 383 CI for quick revs and a better

January 17 2012, 4:41 PM 

rod ratio. I have a 383 CI, and I am constantly amazed at how quickly it revs. You could use a 3.750" stroke, 6.125" rod, and still good ring package at 1.200". Joe-JDC.

 
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Brent Lykins, B2 Motorsports
(Login blykins)
74.134.178.200

Yes...or offset grind a factory crank for a 377....n/m

January 17 2012, 4:58 PM 



Brent Lykins
B2 Motorsports, LLC







 
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blizz
(Premier Login blizzardND)
Forum Owner
69.178.219.74

Save the money on the heads and the stroker crank..

January 17 2012, 5:42 PM 

I'd stick the money into a 5 or 6 speed OD transmission, with those gears, a nice camshaft upgrade, roller rockers, a nice set of pistons on prepped stock rods, add a Blue Thunder intake and wind her up a bit, like she was born to.

Trust me, you won't out rev a set of 4V heads or hurt a 351C nodular iron stock crank on a street engine. Most of the street alloy heads actaully flow less than a set of mildly polished 4v's and with a 72 Mach, the weight iron vs alloy difference will not be noticeable.

With the OD tranny you will have the best of both worlds, a ripsnorting Charging Rino 351C or in your case 357C, that you can drive to the dragstrip and home afterwards. And brag to your buddies that she's basically stock. happy.gif

Trust me ( I own one) a car that's to hard on gas or hard to cool, is a car you probably wont drive as much as a well tuned well behaved crackle sharp stock stroke car that you can drive though the neighborhood at a comfortable rumble. Isn't driving it, the real reason for the hot rod in the first place?

Its all in how you are going to drive it. 4:30's 4speed even in a heavy 72 mustang is still more than enough for a smokeshow with a well tuned 357C. Up the Cu in to 383 or 408 and the higher torque will have you swapping gears due to the breakout force leaving the stop signs and lights.

It's your car and your money but you asked for our opinion, I'm here to help you make the most of what you have, and you have a bunch already. happy.gif

welcome to the forum, let us know what you decide.




Happy New Year 2012!!..

 
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blizz
(Premier Login blizzardND)
Forum Owner
69.178.219.74

Be sure to check out the engine builds page of this forum

January 17 2012, 5:46 PM 

You can see what other guys have built,
then by clicking on their login name you can email them to see how they like that particular build.

good luck
-blizz

Happy New Year 2012!!..

 
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