stroker dyno results

[Roscoe]

Forget all the articles, dyno software and half the advice and listen to this.

Two friends of mine just had engines built. Both wanted to run on the track and wanted them to be 500+ engines that were reliable and would not blow up. One guy was on his 4th engine!

They went to Hoffman Machine in South Plainfield, NJ. Dennis Hoffman built them basically the same, with minor variation. It went something like this:

351W Dart block stroked to 408. this has a Cleveland lower 4 bolt mains and looks like an indestructible block.

Forged Crank, hrods and pistons.

AFR 205 heads

One had the Torker II intake and AED carb, don't know the other but believe it is an 850 Holley.

Roller cam and rockers

One had a more radical cam than the other, both by Comp Cams.

OK the engines were put on the engine dyno and one recorded 615 hp and the other 570hp.

That's all I have to say,
Roscoe

[lostpatrolman]

Im sorry, but i would be more willing to listen to a well documented engine buildup from a respectable company that listed every part used on the engine then from someone who has some friends that built some engine with some cam that was more radical then the other, with some sort of forged piston, unlisted compression, and very sketchy at best descriptions of the two engines that slightly differed from one another. Maybe that is just me though. Great information!

[Roscoe]

Lost,
I was only trying to tell this guy that he should go to an experienced engine builder. I do not know enough about the two engines that THE ENGINE BUILDER BUILT, to comment any more than I did.

To listen to 14 different opinions can only confuse someone to the point of exhaustion. My suggestion was that he should speak to an engine builder that specializes in small block or big block Fords.

I guess you have to go back and re-read my post and you will realize that I was talking about an engine buildup from a respectable engine builder that really knows his stuff.

By the way, Hoffman Machine also builds engine dynos and builds specific engine parts for NASCAR racers, among others.

Don't be so fast to jump the gun, just because my post followed yours does not mean I was referring to your post!.....hmm or does it?
Roscoe

[coyled]

I am running a 1 7/8 to 2 inch step header on yates heads, and its plenty of header, 358ci, 660hp, 530ft pounds of torque. Regardless of engine size or builder, spend the money for the dyno and break in. That way, you know what you have. Any problems at that point will be the builders. As far as longevity, it will depend on the quality of the parts. Scott.

[Great Asp]

Lost,

Roscoe is right on.

Hoffman Machine is one of the premier builders in the country (I like Keith Craft too). One thing, a real builder is not going to give up all the components of a successful build. They shouldn't either. It's why us guys go to them in the first place. Because they know.

I love my Performance Engineering 418, anyone that knows me, knows I would not say it if it was not true. You can use PE without issue. So there, I plugged my builder. He deserves it.

Okay, the Dart block is a great build for 500+ HP, and I was about 3 months behind the curve, or I would have one. It makes a nifty 427!

Best thing to do (unless you build motors for a living), is to have someone who knows what they are doing build your 500+ hp anvil. It is a more specific build, and needs to be built for a light car too.

IMO

Eric

[DaveR]

Asp,

What intake are you running? I'm getting ready to build a 408, but I want it to be streetable. My concern is drivability below 3000 RPM. Some threads say that a Victor Jr. destroys the bottom end, others say it doesn't matter in a car this light. I suspect that there are two perspectives, first, the crowd that likes to drag race from stop light to stop light and is disappointed if they can't smoke their tires, that's not me. I want reliability with a little extra mid range oomph for the occasional trip to a road course, and will probably set my limiter at 6K. Also, if you are running a single plane, do you have hood clearance problems?

Anybody have experience with the Hawk Racing stroker kits on E-bay? They are selling a 408 kit with cast crank, I-beams, and KB pistons for $849.

[Newstang4me]

I'm new to this site, but have been working on cars since I was three(well ok fetching wrenches for my dad at three). We always had Fords and a few Mopars. In my opinion I'd do a 351W based stroker for the numbers you are looking at. Stay away from cast internals for parts. I have looked into numerous companies in reference to strokers(Coast High, DSS, Hawk, Wynne Speed). They are all going to push their product, but I have gleaned a few tidbits that they all seem to have in common. The 347 used to have oil consumption problems, as the wrist pin was intersecting with the oil ring. This isn't a big deal with RACE engines, but the guys that were using them on the street were having oil consumption problems. None of the 351W based strokers seem to have this problem. Some of the new 347 strokers have a modified design that supposedly eliminates this. Another concern is the bore to stroke ratio of the 302 strokers. So after all that I'd choose a 351W based stroker using quality components. For my dream Cobra I am in the process of building a 351W 427 stroker from Coast High Performance. If you have any Q's about it just shoot me a email.

Just my 2 cents.

[427 S/O]

From Klotz's web site.....Klotz Octane Booster provides extra octane. 1 oz. per gallon of gasoline will raise octane 1.5 numbers.

Their not explaining in detail and for good reason, profit. The 1.5 numbers they use will raise your octane from, (example) 93 to 93.150....no way is this going to make any noticeable difference and I'll bet their using toluene, which costs about $23.00 for five gallons. Mix your own.........

[CCX33911]

You can check out my build on:

www.2gmotorsports.com under dart 427. The engine was built by Keith Craft and dynoed by them. The engine made 615 HP at 5600 RPM and 619 ft-lb at 4600 RPM using 1 5/8" primaries (same as I currently have for the GT40). The engine really could use 1 7/8" primaries however I have not had a custom set made for the GT40 (but will). Nice combo using hyd-roller cam and 10.5:1 (pump gas). The AFR's are hard to beat.

[lostpatrolman]

How much is an engine buildup/ dyno break in for a company such as keith craft or hoffman? lets assume an engine like roscoes friend's, or CCX33911?

[Curt C.]

Roscoe,

Any idea how much the cost of one of those engines was? Just curious.

[CCX33911]

Originally posted by lostpatrolman


How much is an engine buildup/ dyno break in for a company such as keith craft or hoffman? lets assume an engine like roscoes friend's, or CCX33911?

It is all a function of cost of parts going in. In my case, KC charged very reasonable costs for the parts (compared to other order places such as Summit). The labor included standard rates for honing, etc. Then there is a $800.00 charge for assembly. Dyno time is ~$450 plus fuel. In my case the total came to something like $11,500 including dyno time and shipment to VA.

Going to expspensive items such as the Dart block, AFR 225's, and 4340 crank and rods adds to the cost, but is required to let the motor live and make the power.

[Charlie]

I notice most of your stroker build-ups are using AFR heads. Are these better than the Trick-Flow heads, and if your answer is yes, then can you give specifics? And what about the SVO GT-40 aluminum heads? Nobody seems to be using those, although coyled is using the Yates heads. I assume that means the GT-40 heads just don't flow well. Any opinions on this?
Charlie

[Roscoe]

You can't beat AFR heads.

I don't know what Roger paid but Bill's 408 from Hoffman came in at around 9-10k. This was with Hoffman ordering all the parts and included the assembly and dyno.

Roscoe

[CCX33911]

Air flow makes HP. Short of the all out racing heads ( Yates $4000.00, etc.), the AFR heads flow more air more efficiently. In other words for a given intake runner volume (same for exhaust), they flow more CFM of air at a particular valve lift. I am talking out of the box condition not ported. Certainly one can take any good head to a good head porter and get good flow numbers. The high flow AFR's are CNC machined for the runners and combustion chambers. This ensures consistency between cylinders.

AFR will send you a catalog that provides there flow data as compared to other brands (most comparisons are for SBC, but SBF would show same trends). Also there is a large head shootout going on in future issues of Mustangs and Fast Fords. They are leaving out AFR 205, 225 because they consider them to be race heads. I think this is a bad idea. I would like to see a shootout include all heads. Broken into catagories based on intake runner volume (e.g. 160 -180, 180 - 200, 200- 215, 215 - 240, etc.).

[Mr.Fixit]

Total airflow capability at 28" vacuum with .700" valve lift is along the lines of what you see in airflow charts. that is an indicator, but velocity should not be sacrificed, as it is as important. Big runners lose velocity, small runners lose overall flow capability. It's all about finding the balance between these two peramaters for your particular engine combination. bigger is not always better. A small runner head that has been massaged by a good head porter, will often outshine a big runner head that flows more CFM's.

[CCX33911]

Good points. That is why it is important to compare heads within the same family of port volumes. Within a given port volume the higher flow rates will have higher port velocities. This combination must be sized to the desired engine. For example the AFR 225 would be a dog on a 302 CI engine, but the AFR 165's would severely limit power on my 427 CI stroker. AFR has a nice article where they substituted a set of AFR 185's on an otherwise stock 392 Ford Crate motor ( http://www.airflowresearch.com/artic...le04/A4-P1.htm ). The result was a 75 HP gain with torque gained accross the board. One might assume that you would loose low in torque (due to velocity issues) to get high end power, but in this case it was a gain everywhere. AFR has put a lot of time into efficient port design to get high flow for a given port size.

[Great Asp]

427 S/O,

My can says 2.5 points with 1oz to 1 gallon, and that is a "full point", not a 1/10. So 93 octane goes to 95.5. See http://www.klotzlube.com/support/techsheets/KL-602.pdf

FYI I called the tech guys at Klotz, and they said they just finished a study with Ford Motor Co, and the results were even better than what the label says.

It does not use Toluene either, but it has a "special" smell.

I mix like 16oz to 12 gallons when I fill up. It makes a noticable differance from the "NOZ" brand octane boost I was using before. I plan on Dynoing the motor soon, as I think I can get a little more timing out of it!

I was told by a buddy to try this stuff, and it works better than I would have thought. I recommend Klotz Octane Booster.

Eric

[Great Asp]

DaveR,

I forgot you.

I have a Vic Jr. intake, and although it does not like to be in gear under 1500 rpms steady, I have had no problems. I think the big differance is you would normally run more rev's with the single plane instead of a dual plane.

The intakes are a jump ball. There are lots of engine builders that will tell you to use a dual plane for the street. Same guys will tell you to use a vacuum secondary. I currently use a Race Demon 750 with mech secondary.

I have had both set ups on a cobra. I prefer the set up I have now. The vacuum secondaries might keep you out of trouble more than mechanical. But if you are talking about a 500+ hp motor, I would go for the single plane and mechanical secondary.

Eric

[Snakebit]

Canfield heads flow better than AFR and they have a higher rail around the top of the head so you can use roller rockers with stock valve covers