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Author Topic:   SBC: 3.48 stroke vs 3 9/16 stroke?
stevenwm
Member
posted July 09, 2003 07:59 AM
Which one of the sbc strokes would be best to build and what is your opinion of the difference?

Can the 3.562 stroke crank use a 6" Rod and if so would the 5.7 or 6.0 rod be better say in a hobby or street stock?

Looking to build some horse power considering right now a hobby engine with a maximum 366 C.I.Flat top pistons and any lift hyd camshaft.

The heads can be vortech-camel humps-or oem as supplied from factory.What heads would you recommend?Can run screw in studs and guide plates and steel roller tip rocker arms.The intake must be cast iorn with a oem quadrajet 4bl carb.Can run headers to that exit under the car.

The car will be in the 3200 pound range and will be running either on a 1/4 mile clay oval or a 3/8 clay oval.It will be a metric frame car buick regal 108" wheel base with a 9" ford rearend.Also what gear would you suggest for the two tracks.

Thanks for any help.I was told that the 3 9/16 stroke sbc would eat the 3.48 stroke for lunch.Just curious.

Some of these hobby stock boys are running like street-stocks and I wanta be competive.

Thank for your help.
Steve.


stevenwm
Member
posted July 09, 2003 04:08 PM
Not much advice on this one hugh?...lol

Still waiting.
Thanks Steve.


rico 08
Member
posted July 09, 2003 04:15 PM
I had a 9/16 stroker once and it was a good engine with very good parts,it came from the 360 cid sprint cars they run in oklahoma,guess it was sort of a cheater engine for that class,you can do the same,they will surely allow you an extra c.i.d.


dirtbuster
Member
posted July 09, 2003 04:46 PM
When you start talking 9/16" you start talking high dollar pistons, because it is not that common. I think they are a great motor and you can buy those cranks already to go but after a while things start to add up.

If it were me i would stick with 6" rods, 2 releif flat top pistons and if your block hasnt been decked go with a 3.5 stroke aftermarket crank. With a .030 over block that gets you a 357 (362 W/ .060). Then throw on the vortec heads and you have about 9.5:1 compression. You would have a good running motor without a lot of trouble or expense. The vortec will run circles around any other stock head. Just stick in some good springs and its a good idea to add guide plates and screw in studs while your at it.

stevenwm
Member
posted July 09, 2003 05:43 PM
DirtBuster.

Thanks for the advice.

I plan on a hobby stock engine with a Forged Steel Crank 3.562.(30 over decked block).

6" H-Beam Rods.

Balanced assembly.

Forged flat top JE or Ross Pistons.
.035 File fit Dura Moly rings.
Clevite H Race Bearings.

Lunati Hyd Camshaft special grind.

True double roller timing chain assembly.

Vortech Heads big valves and screw in studs and guide plates.Vortech cast iorn intake for a quadrajet 4 b.The quadrajet 4`s I know a few tricks on.

Dynatech headers triple stage with the muffler incerts.

1.5 and 1.6 steel roller tip Comp rocker arms.Comp 80 wall push rods.

TCI Powerglide automatic.

9"Ford rearend.

Money isn`t a problem just want it to be in there with the competition.

Maybe it will be in the competition?

Thanks again Steve.



dirtbuster
Member
posted July 10, 2003 08:08 AM
Well if money isnt a problem i would say go for it then. I didnt think anyone would want to put that kind of money in a hobby stock engine. Around here the hobby claim fee is only 300$ and most spend around 1000-2000$.


stevenwm
Member
posted July 10, 2003 09:45 AM
DirtBuster.

There are no claims on the engines or anything else where we race here in the south.They can protest the engine or other car parts for $250.00 though.

If found illegal the protester gets $200.00 back and the track gets $50.00 of the protest money.The illegal car and owner gets dq`d and suspended for one week and if caught illegal again he gets suspended for the rest of the season.

The competition in the hobby stock class here is very tough and if you want to be in the competition here in the south you better not be running claimer stuff.

Thanks Steve.

racer17j
Member
posted July 15, 2003 08:10 PM
dirtbuster you'd be suprised at what guys will run in a hobby in fact i hate to say it but there might be a claim in the next few weeks because a kid bought a 9/16 for our class and has been running his mouth about it and our claim is 200 lol. but i dought he will sell since he is not in for points if he doesn't win he pulls in


dirtbuster
Member
posted July 15, 2003 10:14 PM
well if there is no claim and a just a protest rule and money is no option then i would say you have the makings of a very stout engine. If that is what it takes to keep up and no chance of losing it and stay legal then I would go for it as well. It does surprise me sometimes to hear what people are building in some of the hobby classes. I know guys that are buying 1500 lightweight cranks for a 300$ claim class. Just seems crazy to me......


Raz_900
Member
posted July 17, 2003 03:34 PM
quote:
Originally posted by stevenwm:
DirtBuster.

Thanks for the advice.

I plan on a hobby stock engine with a Forged Steel Crank 3.562.(30 over decked block).

6" H-Beam Rods.

Balanced assembly.

Forged flat top JE or Ross Pistons.
.035 File fit Dura Moly rings.
Clevite H Race Bearings.

Lunati Hyd Camshaft special grind.

True double roller timing chain assembly.

Vortech Heads big valves and screw in studs and guide plates.Vortech cast iorn intake for a quadrajet 4 b.The quadrajet 4`s I know a few tricks on.

Dynatech headers triple stage with the muffler incerts.

1.5 and 1.6 steel roller tip Comp rocker arms.Comp 80 wall push rods.

TCI Powerglide automatic.

9"Ford rearend.

Money isn`t a problem just want it to be in there with the competition.

Maybe it will be in the competition?

Thanks again Steve.



I would stick with the stock stroke or 3.5" as mentioned above. For a couple CID, you're spending alot of extra money that could be spent elsewhere with more benefit.

I run a 355 with a PG also. Best things to do are get the rotating weight down. We've had 2 motors that were fairly close. LW Keith Black pistons (KB231 w/5.7 rods and KB260 w/6.0 rods), 6" damper, 153T flexplate and a TCI circletrack convertor (PN 741020) If rules allow, a non-functional direct drive convertor is the ticket (9 lbs lighter than the functional convertor that is already like 8-10 lbs lighter than stock). The 6.0 rod motor's rotating assembly is significantly lighter than the 5.7 motor. The 6.0 rods (Eagle SIRs) are 8 grams lighter than stock and the pistons are ~50grams lighter than the 5.7 LWs (which are 50-60 grams lighter than stock pistons) The KB's are relatively cheap too going for under $300 a set.

The 6.0 motor now has almost 2 full seasons on it. It's had a rough life with 2 broken pushrods, 3 broken rockers and bad gas that burnt a hole in 1 piston. 1 new piston, 1 new set of rings and reused bearings and put it back together. That was 25 races ago and it still runs hard as ever. It's actually too much motor for our track and tires. It sees 6500 all the time and has gone to 7200-7400 way more times than I care to count. Especailly on a stock cast crank. (Knocks on wood REAL hard).

I use all Federal Mogul pieces (perf bearings, 1/16" rings, t-chain etc) and a Lunati .534" 245@.050" cam. Although we get to use a Performer intake, 3310 carb and 1 5/8" headers too.


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