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chasing stroker kit for 351clev

20K views 95 replies 22 participants last post by  davis 
#1 ·
chasing information regarding stroker kits.Want to build 378 or 383 i have not been able to find any clear information (not to clued up on engines) looking for around 450 hp flywheel .Going to run roller cam roller lifters roller rockers and Also looking at CHI heads and manifold.Does anyone know of web site or wholesaler. I live in perth .Any help would be great
 
#4 ·
why don,t you just offset grind the crank to 3.7 inches.use 350 chev large journal rods narrowed to suit clevo crank and modded pistons.with open chamber heads and suitable deck height you can expect around 9.4 to 1 comp ratio.balance your assembly.It should be cheaper to do it this way than have to buy a custom crank and the smaller journals are better anyhow.Speak to the guys at performance mods they should be able to do this easily.
 
#7 ·
Tony me also in WA, did my stroker based lossely on the way COME do it. Turned out very successful for me. You wouldn't go back to a 351 after having driven a stroker, heaps of torque and the big breathing clevo heads almost seem like they were designed for more swept capacity.

I used 2V's, heavily ported with 4V exhaust and 2V inlet valves. Used standard crank offset ground to 3.7inch stroke and resized to fit the Chevy rods and ACL pistons off the shelf to fit. Lots of metal needs to come off the crank, counterweights modified etc so can be expensive to do right and keep all in balance. Crank alone for me was about $1000.

People say strokers have problems with revs, vibration etc. Total bullshit and based on heresay. You get much more dyamically out of the motor than just the displacement increase alone would indicate.

450 FWHP not easy to achieve with a 351 but much easier with a stroker. I'm way over that with my combo.
 
#8 ·
Thanks heaps for this info Strokexd. I have been doing heaps on research in Perth and through-out Aust and finding it difficult to find the parts I need to do this. Perth also seems abit overpriced compared to east. Did you have yours built or build it yourself? I have also been looking at new Scat Crankshafts. They list a crank for the 351 with 3.750 stroke with 6 inch rods. Not knowing much about engines, is that the same as what you have done yourself?
 
#9 ·
I wouldn't say 450fwhp is hard. You just need the right parts and preparation on a 351. I had it. I wou;dn't say it's ideal for a drive to work car but hell I drove it to and from work. Cranbourne-->East Bentleigh about 90-100k's total.

With the CHI's your on the right track. Going a roller cam makes it even easier to achieve. You should piss it in easy.

That kind of power with a stroker is a hell of a lot easier due to the increased cubic inches.
 
#10 ·
Tony the Scat crank kit is also a way to do it, I just didn't do it that way myself. So I couldn't vouch which way way is better, but I suspect it would work out more expensive than offset grinding a 351 crank. As it was, my motor still cost $7500 plus ancillories like ignition, manifolds etc, so it was over $10k by the time I finished.

With a 3.75 stroke and .030 overbore you will get 383cubes, I used 3.70 stroke for 378cubes. Sounds like same rods are used, but I don't know of the merits/issues of the slightly extra stroke on the Scat crank. Suggest find out if off the shelf pistons can be purchased, they can in my situation (ACL's), but with the Scat 3.75 stroke you might be up for a set of custom pistons.

I got Alan Nylander at AJN's to assemble my motor together with some intellectual input from Gary at Performance Unlimited and Leon at A1 Hi-Performance for cam selection and head work.

Keep me posted how it all goes.
 
#11 ·
I used a Scat 4340 crankshaft in m 393" stroker Cleveland. It made 608 FWHP (448 kWh) at 7600 RPM and 510 FWTQ at 5600 RPM, which also diffuses the BS about a stroker Cleveland not being able to rev.

I used a 3.850" stroke, 6.000" rods and custom pistons. 450 FWHP is easy for a Cleveland with or without stroking it. Just add plenty of $$$!

Here is what the Scat part looks like when you first take it out of the box:



:davis:
 
#12 ·
Thank you for the info it will all come in handy . I will be starting this engine from a block and going from there. I want to do this engine right the first time .I would rather spend more time researching and a little more money .than just throwing money at it . I will probabley give leon at a1 a call and will look in to the scatt cranks. I also work at coventrys auto parts so have some access to some brands (acl crow yella terra etc)but not to much in performance wise.Please any more info would be great
 
#13 ·
Re: chasing stroker kit for 351clev (photos added, large!)

Tony,

I started with a bare, '72 351 CJ 4-bolt block from a Q-code Cougar. I used Milodon center main bearing caps. These have much more material throughout and especially in the area surrounding the outer bolts. They require a good machinest to properly register them and, obviously, to align hone them. I used a combination of ARP studs to fit the front factory 4-bolt caps and the taller Milodon caps used in the center caps numbered 2, 3 and 4.



I used custom JE/SRP Pistons with floating pins in a flat-top w/valve reliefs configuration. These give me a calculated 11.28:1 compression ratio with my 66cc heads and .040" gasket with a .008" deck. The oil ring does intersect the pin, but uses "buttons" to maintain/control the oil so that blow by and/or oil consumption is not an issue.



The rods are 6.000" long "Chevy" rods in an H-beam configuration made from 4340 chrome-moly steel. They are reasonably light and very strong. Not as strong or as light as a set of C&A or Oliver rods, but at only 25% of the price, too.

The bore is 4.030".



The balancer is a lower-cost SFI-rated part from Performance Products. The timing gear and chain set is Australian made and both gears are billet steel.



The block has both intake and exhaust valve reliefs typical of a "CJ" block.

I used a set of Ford Motorsports A3 cylinder heads that I bought bare from a guy. These heads flow much more than most other heads, but I am building a high compression "cousin" of this engine using a set of the AFD 4V heads due out soon. I believe that the AFD heads are a better overall design, especially with regard to the combustion chamber shape, spark plug location and port sizes. They also benefit by taking factory extractors, which the A3s definitely do not.




Flow figures at 28" are as follow:

Lift--int-/-exh
.200 152/100
.300 217/146
.400 266/194
.500 305/217
.600 341/232
.700 357/242

This is fairly significant flow for any small block application and resembles most big block "out of the box" cylinder heads.

I used a "Blue Racer Woverine" solid roller camshaft. Blue Racer cams was bought by Crane. I bought this camshaft for about $110.00 (US) new. While it doesn't necessarily sound like the "best" camshaft for the application, I spent considerable energy researching/searching for any cam that would make even a bit better power. I didn't find one that would justify the expense of something over $365 (US) for what amounted to perhaps a 3 HP gain. The details of the cam (single profile design) follow:

274/274 @.050" .709"/.709" lift 105 LCA

Crane apparently still has these cams and is getting rid of them at "basement bargain" prices. This particular cam would love additional compression up to about 13.5:1, IMO. It wouldn't be terribly radical for a street engine with 10.5:1 if that engine was a larger stroker size like a 393 or a 408. This camshaft definitely likes to run and sounds very aggressive at idle, even with the extra inches and free-flowing cylinder heads.



The part number is: WG 5016 MR

I must have compared 50 different mechanical roller cams and at least 10 flat tappet mechanical cams after I already purchased this cam just to see if I couldn't find a better choice for my combination. The best that I could do was simply push the RPM band where the engine made power farther up in RPM. While the heads would definitely support more RPM, I didn't want to build a really high RPM engine as I want to conserve parts and not have to change valve springs every week. As you can see by the details of this cam, .709" is not a lot of lift, especially for a "drag race-dedicated" engine. More lift didn't really help during software modeling of the engine, except in RPM ranges well beyond where I wanted to run. Interesting is the idea of using these heads on a 331" destroker at 9,000 RPMs on alcohol with a 25% nitromethane kicker for about 1100 HP and a serious Cleveland screamer. But I'm not that interested in changing valve springs.

I used titanium valves on the intakes because of the 2.19" size and extra .100" length, which made them a bit heavy for a stainless steel part. I used stainless exhaust valves, though.

Valve control is a very important topic to me. Most people do not realize that the valves bounce on their seats up to several times before finally settling down and seating completely. Reducing the bounces and seating more quickly is important as the RPM goes up where there is less total time. Any valve train "inconsistencies" need to be addressed so that cam timing is not adversely affected by misbehaving valves.

I've seen mentioned that single coil springs with dampeners are recommended, but I tend to recommend double coil springs with dampeners for anyone but the most obvious "RV cam" application where RPM is definitely under 6000 RPM and lift is under .500" at the valve and when a wide lobe separation is used or something greater than 112 degrees. There will always be someone around to tell me that they're running just fine with parts that satisfy them and do not fit my requirements. Pure flat hydraulic lifter cams are an excellent example of where it may make sense to avoid using too much spring, but you can achieve better valve control using double coils with reduced spring pressures compared to single coils while making each spring live even longer using two instead of one. Also, if you break a coil on an over rev or something, a dual coil spring might retain your valve whereas a single coil will likely drop it. I do not, as a rule, plan for failure, rather, as a rule, I build to prevent failures. The lower cost single coil springs would be adequate, IMO, for a truly street driven daily driver kind of car where the RPM is limited to 5500 and very rarely sees that much.

For a play toy with an abundance of ponies, I prefer to run it up to 7000+ and enjoy the look on the Holden drivers faces when you switch to 2nd gear after they're already all in. Of course, one must look quickly and in the mirror for that fleeting but worth it blank stare of disbelief, since one will quickly be accelerating from view in nothing flat.

I used a Mellings high volume oil pump with a chrome-moly oil pump drive shaft from Milodon. I used Moroso oil restrictors to keep the oil out of the top end and in the mains where it belongs. There are quite a few blokes out there who feel that the HV pump is not a good choice. It does use more power, but I don't play the absolute maximum power game anyway. Turning the engine over twice by hand is enough to fill a new oil filter on my engine. I prefer the "regular volume" Mellings pumps for street cars, since fuel economy is always an issue with a true daily driver.



I used an Edelbrock aluminum waterpump to save weight. I am a firm believer in saving as much weight in any car as possible. My entire car with me in it should weigh just 718 kilos ready to race at the starting line. This is an estimate based on weighing every major component and includes a bit of speculation on those items not currently completed on the car now. Included in the speculation is another 90 kilos of unaccounted for "miscellaneous" weight, so if I don't add anything more than what I've got on my list, it could be as light as about 630-650 KGs or about 1.05 KG/HP. That ought to be entertaining!



This image was taken right before making off to the dyno for its initial testing and tuning. It didn't have the valve covers on it or the stud girdles (left off to make adjusting the valves easier and quicker on the dyno) both which are now fitted.



This was dyno day. Power output after tightening up the lash (reduced torque readings) was:

[PRE]
RPM CBTQ CBHP
4500 443.3 379.8
4600 452.7 396.5
4700 454.8 407.0
4800 464.3 424.3
4900 472.4 440.7
5000 479.0 456.0
5100 490.0 475.8
5200 492.6 487.7
5300 492.0 496.5
5400 491.0 504.8
5500 494.5 517.9
5600 490.8 523.3
5700 490.1 531.9
5800 488.1 539.0
5900 487.5 547.6
6000 487.0 556.4
6100 484.5 562.7
6200 481.0 567.8
6300 482.1 578.3
6400 480.6 585.7
6500 475.9 589.0
6600 472.7 594.0
6700 468.4 597.5
6800 464.2 601.0
6900 458.7 602.6
7000 456.6 608.6
7100 445.6 602.4
7200 442.2 606.2
7300 435.2 604.9
7400 431.7 608.3
7500 421.3 601.6
7600 418.9 606.2
[/PRE]

Though I find it more useful to look at these numbers in the form of a graph.



This shows how flat the torque curve is on this combination. I believe that had I spent more time tuning, especially with adjusting the 1000 CFM 4150-style Holley HP carburetor, that I could have coaxed another 30 HP out of it and probably another 12-15 TQ.



...is the where this engine ended up. I've got a few odds and ends to source before I can install the rear end, but I've been working on plumping and wiring the car these past few weeks. The body is being painted and I hope to make some passes by September if the weather isn't still too hot at night.

I'm happy to share anything that I know about engine design and building, but from the point of what I know and what I believe and not as someone who knows everything or even thinks he does. Someone may be running very well on single coils and doing well with them, but you probably won't hear about it from me. I've been accused elsewhere of being a braggart and a know-it-all because I've tried to share what I've done with others who are similarly interested. I hope that I won't come across in that fashion on this forum. I also hope that I can help others understand some of the awesome potential of the Cleveland small block Ford.

:davis:
 
#14 · (Edited)
Your comments will always be welcomed here Davis. I don't know how you manage an essay on every post ;) You have good ideas and knowledge. Others can make the choice of taking it on board or not.

I've been told not to stroke my 20,000kilometre old engine but an extra few ci can never hurt. I'd do a 383 or 396 myself and try and keep everything under 6500rpm, which would make a nice street engine.

My 351 seems to be leaning to more drag use than street due to our registering authorities etc. I am still looking to pull a shifty and get the engine in a street car.

Brenden
 
#15 ·
davis,

Even though the length of your posts are soooo long, I cannot tear my eyes away as it is always interesting, informative reading. :bsr:

Keep the stories coming. Nice engine pics too.

Please continue to give your advice as you see fit, :wnc: and if your comments aren't welcome, don't worry, you'll soon be told. :wgaf: :beatup: :wank:
 
#18 · (Edited)
Tony,you mentioned that you wanted to make around the 450 hp mark which is great and you also mention the use os ally heads , roller cams,stroker cranks etc.Firstly let me say that at this power level exotic parts are not really necessary. You could make it with a set of ported 2v heads ,a solid cam in the 250 deg duration mark (f246 crane and 2vs are good for ~430hp),single plain manifold with a 750 holley blah blahblah,you get the picture.Secondly you mentioned that you have virtually no engine building skills and i,m guessing here but also no tuning skills. Keep in mind that the higher the power level the more temperamental the motor will be and you will need to be hands on,believe me. You will need to constantly make small adjustments to the tune of the engine to keep it crisp as well as being able to do more complex adjustments such as lash which is critical in a roller engine, hence the recommended solid flat tappet which is a little more forgiving. My advice would be maybe start off with something a little simpler in design and learn about the building and tuning aspect as you progress and become more proficient in your abilties. The real joy comes about when you do the dirty work yourself and not have to pay someone to do menial tasks.I hope i haven,t put you off in any way.You meet a lot of guys who have turbo this,solid roller cammed that and the reality is they haven,t got a clue how it works or worse what it means. Starting out at a grass roots level gives you the oppurtunity to learn as you experiment with your motor and when your ready you can always take it to the next level.cheers russ ps ask as many questions as necessary to make informed decisions.
 
#21 ·
Excellent stuff there Davis!

I know someone with an almost identical engine, but it differed in that it was only 378 cubes. It was 12.9 comp, Yates heads, solid roller (don't recall the specs), etc etc... and made 600ish HP on a brake, and 410ish RWHP which is approximately 300RWKW on an Australian dyno. (Dyno Jets are uncommon here) Thats how much power it lost fully front dressed, in a street registered sedan, on a legit Dyno Dynamics run.

Your HP numbers are very impressive, but even more so, the torque delivery. I'm VERY impressed!

Incidently, the engine ended up breaking a steel crank testing a 300hp shot.
 
#22 ·
russxr67 said:
Tony,you mentioned that you wanted to make around the 450 hp mark which is great and you also mention the use os ally heads , roller cams,stroker cranks etc.Firstly let me say that at this power level exotic parts are not really necessary. You could make it with a set of ported 2v heads ,a solid cam in the 250 deg duration mark (f246 crane and 2vs are good for ~430hp),single plain manifold with a 750 holley blah blahblah,you get the picture.Secondly you mentioned that you have virtually no engine building skills and i,m guessing here but also no tuning skills. Keep in mind that the higher the power level the more temperamental the motor will be and you will need to be hands on,believe me. You will need to constantly make small adjustments to the tune of the engine to keep it crisp as well as being able to do more complex adjustments such as lash which is critical in a roller engine, hence the recommended solid flat tappet which is a little more forgiving. My advice would be maybe start off with something a little simpler in design and learn about the building and tuning aspect as you progress and become more proficient in your abilties. The real joy comes about when you do the dirty work yourself and not have to pay someone to do menial tasks.I hope i haven,t put you off in any way.You meet a lot of guys who have turbo this,solid roller cammed that and the reality is they haven,t got a clue how it works or worse what it means. Starting out at a grass roots level gives you the oppurtunity to learn as you experiment with your motor and when your ready you can always take it to the next level.cheers russ ps ask as many questions as necessary to make informed decisions.
russxr67 thank you for the advise 430hp still a very good option . I have only got one shot at this engine and thats why I am so worried about getting it right .I will be using CHI heads and manifold but the rest will depend on real peoples advise such as yours . I only wanted roller cam so it would be a bit more street useable .My biggest problem is I want my car to be better and faster than my mates sounds stupid but true . But at the same time want to be able to enjoy driving around with my family so toneing the power down might have to be an option
 
#23 ·
tony xa said:
russxr67 thank you for the advise 430hp still a very good option . I have only got one shot at this engine and thats why I am so worried about getting it right .I will be using CHI heads and manifold but the rest will depend on real peoples advise such as yours . I only wanted roller cam so it would be a bit more street useable .My biggest problem is I want my car to be better and faster than my mates sounds stupid but true . But at the same time want to be able to enjoy driving around with my family so toneing the power down might have to be an option
Tony,

Nothing stupid about those goals. The key to achieving them is through a moderate use of well-design parts that will work well in a combinative effort. Focus on making broad torque and forget about HP. That's right. Completely forget about HP. HP is an expression of work over a period of time. Torque is what is actually doing the work. Torque moves the mass of the vehicle. Have you ever noticed how the peak HP numbers are oftentimes greater than the peak TQ numbers? Also, that the peak HP numbers occur at a greater RPM than the peak TQ? At higher RPM, the amount of work (torque) being produced is made over a shorter period of time as is expressed in revolutions per minute (RPM).

Building a "torque monster" engine that is well-behaved on the street is easy. First thing is to add about 200 cubic inches of displacement. This is nearly the same effect as running a supercharger at very low boost without the drag of the blower taking a hit on performance or heating the air. Of course, adding that many inches in a 351C package is impossible. A 408 is a tight fit. A 393 stroker is a good choice. Any stroker that adds inches is going to make more torque compared to the same exact engine with just a smaller stroke.

You don't need to build a stroker for "enough" torque for a very healthy street engine, but every added bit means that everything else can be more mild or moderated so as to be even more streetable.

Here is how I might recommend building a nice 351C for the street.

351C 2-bolt mains +.020" (.030" if you want to save on piston prices and your block will take it.)

Australian 2V iron heads, pocket porting (can be done at home) and set-up for screw-in studs and guide plates. Alloy AFD 2Vs if you can afford them. The combustion chamber design will net more efficient burn and make more power while reducing total weight. Flow velocity will also be strong and they don't need to be modified for screw-in studs and guide plates, so that cost will help offset the initial price. Use the 64cc AFD 2v heads for best results.

Factory stock 4MA, ground as needed and straightened. Have it nitrided.

Factory stock rods resized/reconditioned and shot-peened, ARP bolts.

JE/SRP, ROSS or other pistons made to order with appropriate dish. I recommend using no more than 9.5:1 compression ratio with either iron or alloy heads for a "true street" engine. You can use more if you want to fuss with it, but at 9.5:1 or even 9:1 you're going to make as much power (and more) as you can use and the extra compression will just make things more volatile. A dished piston is likely necessary considering the heads.

I'd recommend a nice Competition Cams hydraulic roller camshaft for the ultimate in "true street" performance and driveability. They have a 270HR and a 284HR and I would probably talk to them about doing a "278HR" for me. I'd think that you'd want about .570" valve lift and probably something like a 220 degrees at .050" lift duration camshaft using a split profile with about the following split: int: 220 exh: 224-226 A 110 degree LSA is probably the way to go, but I'd like to use about 112 degees with a dual plane intake for a real serious torque engine.

Obviously you'll want to use a good set of matched, double coil springs with dampeners and good retainers. Use one-piece stainless steel valves. The 2.05" intakes on the AFD 2V heads are plenty large enough or small enough, depending on how you look at it. The 1.65" exhaust valves are also perfect for this application.

Use a good set of roller rocker arms. I like the Crane gold rockers for street engines and the Comp Cams chrome-moly rockers for race engines.

I would recommend using one of the commercially available dual plane intakes with a 4-hole 1" phenolic spacer, if bonnet clearance is adequate. Use a factory-type air cleaner/filter combination. Too many people use open element filters under their bonnets, which exposes the inlet to heated air from the radiator and fan. Air needs to be as cool as possible for both performance and fuel economy and so that the engine runs consistently when tuned. Check with AFD regarding their 2V dual plane intakes. I haven't seen them, so I can't recommend them, but they may be the hot ticket.

This combination should be good for about 400 TQ. I'd add the 393" stroker kit and bump this to about 450 TQ on pump gas. That kind of power would still be very driveable and nice tempered on the street while providing you with the ability to get very nasty whenever your foot gets heavy.

You won't have to do much more than to put petrol in it and change the oil. Use an RPM limiter type ignition to hold it to a maximum of 6000 RPM, though you'll want to try to make peak power at about 5800.

:davis:
 
#24 ·
This is a fantastic read. Seems I read the right thread. Nice work :thup:

I was wondering myself the approximate cost of stroker kit for my XD Fairmont Ghia 302. Seems the answers are here.

For now, will be putting in a mild cam'ed 351 with 4MA crank Clevo (of my shed floor) in mine for the moment but needs some decent head work.
 
#25 ·
This is a fantastic read. Seems I read the right thread. Nice work :thup:

I was wondering myself the approximate cost of stroker kit for my XD Fairmont Ghia 302. Seems the answers are here.

For now, will be putting in a mild cam'ed 351 with 4MA crank Clevo (of my shed floor) in mine for the moment but needs some decent head work.

Cheers
 
#26 ·
This is a fantastic read. Seems I read the right thread. Nice work :thup:

I was wondering myself the approximate cost of stroker kit for my XD Fairmont Ghia 302. Seems the answers are here.

For now, will be putting in a mild cam'ed 351 Clevo (with 4MA crank) off my shed floor, in mine for the moment but needs some decent head work.

Cheers
 
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