SB STROKER HYD FLAT TAPPET CAM CHOICES

I'm building a 410 (early 360 040) with intentions of road course lapping HPDE and HSAX, currently street/hwy (mostly hwy) driven to/from the events. 727 w BM Holes Shot ~2400 stall, 3.23 rear gear, car weighs ~3350 with driver (empty trunk, ~1/2 tank). I'm NOT a drag racer (rarely attend the strip). I run factory power disc brakes and the vacuum SIX PACK (with ProMax mods... runs great!).

I've built the short block with all forged items: Icon 745 -20cc pistons, forged 4" crank, forged H-Beam rods. CR should be around 9.8 with open chamber T/A cast iron heads (see below).

I already have ported T/A heads that have been flowed .. pretty good "stealth" figures. Club's racing class rules favor that I stay with cast iron heads (going with aluminum ~Eddy places me into a much tougher class whereby winning would be more tough to accomplish, at this time, with this particular club); I may eventually change to to the Eddy alum heads (mildly ported, if/when I do... maybe in a few years, maybe sooner). Using my ported T/A heads (now) will save me $$$$.

So, I'm confused at mfg'rs listings as they typically don't make suggestions for "stroker" engines. Suggestions? I want some bottom end rpms, but mostly strong mid-range rpms and decent top end rpms... all for road racing... 3000-6000 racing.

I've been told that the duration needs to be increased considerably for SB strokers, as well as concern about detonation. Any help with suggestions would be appreciated very much. (So far, I've only discussed with Hughes.)

PS: I've ruled out "roller hyd" due to the increased angle of the push rods with the "taller" roller lifters... would become a severe angle, especially for the intakes, and the push rod tunnel would have to be machined larger... so I'll pass on this option of roller hyd.

Something like the Howards 710581-10 might work well. I really like Howards. Cams are made on very nice equipment.
That one is 230/236@50.
531/547 lift..... 110 lsa in at 106
2600-6200 rpm range, strong midrange, good throttle response. Says” lopey ldle” but it isnt going to be lopey on a 410 inch motor.
Ideally, if they could do you something about 6 degrees bigger on intake and exhaust it would be even better. Call them and ask

I’d absolutely put a solid lifter cam in that combo.

Me too. Unless he has a reason related to rules.

With that tight converter I would err on the short side for duration. If you take away bottom end torque you have to pull all the way to the middle of the rpm range that way, much worse than giving away power up top. If you can, consider a change in converter stall. a ten inch converter will set you back a few bucks, but can be built tight enough to provide very good lockup at cruise, yet flash to 3200 to 3400 behind that 410. I have a 10 inch from A&A, said to be tight, and it flashes to 4,000 when I matt the throttle at low rpm in high gear. Mine is supposed to be the tightest of the three they build, but I suspect I got a loose one. Still locks up enough at 65 mph with 3.55 gears that I am OK with it. My cam is a Thumpr hydraulic roller 235/249/107 in at 105. Fairly radical and makes peak torque 518 at 4600 and peak hp, 504 at 5700, 500 hp at 6,000.

Agreed. Solid lifters will get you closer to what you want.
Hughes Engines has some pretty aggressive solid grinds.
R.

http://www.hughesengines.com/TechArticles/10408416strokerdynotestingsept2002.php

Call this guy. ^^^

Ditto!!!

Also, while it is true a stroker will eat up some cam duration, it is not a severe gobbling up of degrees. The combo of a bigger engine no matter how the bore and stroke are done eats cams duration. The long stroke into big inches is like a double whammy in a sense. The big engine and stroke eat cam duration togther and it will shorten the power band by a few hundred rpm. The long stroke tends to peak early.

Considering your goals and running gear, IMO you still will not need a big cam. I like the solid cam idea and it is only trumped by a solid roller.

Best of luck.

T/Anks for the replies so far. I'm getting educated... more duration is obviously needed for more CID, especially a longer stroke such as the 4".

The LSA degrees puzzle me... 106, 108, 110, 112?... having vacuum is needed for my power brakes (during low rpm and off-throttle braking during racing). I'd prefer not to have a rough idle, somewhat smooth... a little lumpy is ok.

I don't want the cam's power band to fall off suddenly... I need it to be strong and wide between ~2500-3000--5500-6000... lots of mid-range.

Solid cam would be ok but I'd favor hydraulic simply because it will be
street/highway driven most of the time... actually... going to/from the road race tracks.

I've tried uploading the CompCams CamQuest program... won't load.. and they don't answer their phones or e-mails.

;The LSA degrees puzzle me... 106, 108, 110, 112?... having vacuum is needed for my power brakes;
The more cubes for the same size valves need more duration at overlap to get the job done. A 340 might be happy with a single pattern cam of 108 lsa, a 416 might want 104 with the same heads. That Is why I like to go to someone that custom grinds cams. They aren't going to sell you an off the rack cam that sorta fits all.

This is why you need to call someone NOT named Comp who will help you. LSA is a product of all the timing events. You're not going to learn it all from a forum.

Call several cam grinders. Write down all your questions beforehand. Take notes.

Most cam grinders will spend the time with you to explain why they do what they do. I prefer to use small companies, where I get to talk to someone who isn't paid to sell cams from a catalog.

hi!
Lunati have two 'happy' solid flat

404A1LUN 270°/270° adv, 243°/243°@ .050, .548"/.548" lift, 110°/104°
404A2LUN 278°/278° adv, 251°/251°@ .050, .570"/.570" lift, 105°/99°

I use the 404A1LUN in mu 418ci stroker

That was not my experience with the MP509 in my 493. It fired on the dyno and loped just like every 440 I've ever heard with one. I was thinking it would take it to 6pak cam territory.

As my builder told me, 76 deg of overlap is 76 deg of overlap.

This is where the magic of stroker displacement shines. The idle sounded like it was going to be a dog to 3000 rpm but it made torque from off idle, 500 ft/lbs by 2000 and 600 peak at 4000. The only reason I put a 2800 converter in it was to keep from banging the driveline putting it in D at 1100 rpm.

Vacuum was borderline for power brakes, 7-9 idle and 12-14 cruising, a little more if you chopped the throttle from speed.

Kevin