sbc 388

[badfast47]

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

Read more: http://thedirtforum.boards.net/threa...#ixzz3MlGUsJUQ

[50j]

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

[badfast47]

Maybe 215's ?

[DaveBauerSS6]

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

[badfast47]

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.

[Brian Gray]

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

[ford396]

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

[badfast47]

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

[50j]

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

[Lizardracing]

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

[Brian Gray]

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.

[50j]

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.

[Lizardracing]

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

[50j]

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

[let-r-eat]

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

[stockcar5]

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

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

[badfast47]

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

[badfast47]

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 ?

[stewie]

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.

[badfast47]

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.