sbc 388

It has 6" rods and hyper flat top pistons, .600 .600 lift roller cam, roller lifters, roller tip rockers, victor Jr. high rise aluminum intake and a 750 Holley hp double pumper carb. I'm wanting to use a set of Dart cast iron 230's 64cc 205/160 valve angle plug heads. Would this enough engine to compete on a 1/4 to 3/8ths track? The car is a 3000lb. street stock. I figure i will competing against some 400's and wondering do i need to go with the bigger cubes to keep up. Thanks

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Different heads may be better. If you go too big it'll be lazy.

Maybe 215's ?

Need to consider 50cc chambers to get the compression up if you are starting from scratch on the heads. Get some full roller rockers.

So 50cc and 215 on the runners ? What about the valve size ? The full roller rockers won't be a problem to get. Thanks for the help so far.

That is way more than you need. Don't let people tell you different .

If going to a 50cc dart head. Be sure to check piston-to-valve clearance.

That is one thing i was told about was the valve clearance. I may just stay away from that 50cc head.

You end up with around a 21* valve angle with them and it can cause some problems.

Why does dart say the 49cc head has a 23' valve and you say the 50cc head comes out to 21'? I'm confused.

They have been misinformed. Or over sold on angle cutting a head.

Just buy a 602 crate and go kick some but! These guys that spend big money on street stock motors kill me. I have 3 track champions running 350s with vortec heads all with basically what comes in a 602 and guys swearing they have 430s. Save some money spend it on shocks and corrected suspension geometry . Save the headache. That 602 will be more than you can use even in the tack and get you about 70 to 80 nights of racing.

Or just build what you have it will be fine.

No need for confusion, check a set or do a Google search. Dart does say now that they are cast as 49cc and not angle milled from 64cc to get there but that the pistons need to be able to accommodate a 21* valve angle because of the valve location in relation to the bore center.
They may have been angle milled in the past.

Thanks for the clarification as I didn't know that.

No problem, I didn't either until we ran into it.

The RHS 50cc head works fine too. 12336 part number for the bare head.

Quote:

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Originally Posted by let-r-eat

The RHS 50cc head works fine too. 12336 part number for the bare head.

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RHS hasn't produced iron heads for a couple of years now. Might be able to find some used ones though.

I did see the 12336 rhs head on ebay but it was just the 1.

I've decided to use forged dome pistons and roller rockers. So will this be a good combo to use or should i still think about building a 400 ?

I don't remember if it was on purpose or by coincidence, but on a 350 sbc the Mahle flat top piston valve reliefs lined up properly with the 49cc milled Dart head valves.

Since i stared this post i have bought a little m block. It's used and in the machine shop being checked over. The bore is 4.185 with 400 mains. I want to use the flat top pistons and 6" rods but can't decide on the crank stroke. A 3.750 or a 3.875. I'm going with the 230/64 cc dart angle plug heads 2.02/1.60 valves and a victor jr. intake. What stroke would be enough and what kind of lift and duration for a cam would be good on a #3000 lb. car turning at least 7500 rpm's.

To be honest,if i had to buy a crank it would be 3.875 stroke.IF your track is heavy during heat races you can use every ounce of that engine in a 3000lb car.I'll admit,you may not put it the dirt when it slicks off a bunch,but you will like it when you need it.I promise.

BTW. Dart 49cc 215 runner heads with valve relief flat top pistons,and a 9.0 decked block,using 0.41 thick head gaskets,i don't think you will ever have a problem with valve clearance and your compression will be up there.

The 3.875 crank is the way i have been leaning. Don't think i will be able to get the 49cc heads so the cam is my next big thing to decide on.

howards 112323-6 or 11223-6 solid rollers.edelbrock 2925 would be better than the victor jr.

should be 111223-6 on the second cam

This is what i ended up with. 3.75 stroke, 4.185 bore with flat top pistons, dart platinum 230 64 cc heads, victor jr. 2975 intake and a holley hp 750. Going to be on a high banked 3/8 th's or flat wide 1/4 mile. Have the .600 lift cam. 257 267 @.50 .600 .600 lsa 106 IC 102. Do i still need more lift to make this thing work better ?

After re-reading this i have the 2925 victor jr. intake. Put the 600 cam in and sounds great in the garage. Hope to race it tomorrow and see what it can do. Some say the 600 cam may be good for low end torque. Motor comes out to about a 413. Should be healthy.

2925 is a super victor which will be better for you. I would of liked to see the 3.875 stroke with the heads you picked but it will run fine as is. Good luck

750 probably isn't enough carb for it. Good rule of thumb is 2cfm for every cubic inch. I'd want an 830 on it.