18 Degree Intake vs 23 Degree

[jreiley]

I'm rebuilding my sbc race engine from the ground up. I will be replacing the heads, intake, valve train, etc. Would going to a 18degree top end make sense? I'm shooting for 700hp.

[TS1955]

With the right components you can get 700hp from a 23 deg motor.

TS1955

[curtisreed]

But not as easy as from a 18° motor. We have a 406 that made 705hp with 23° heads and it has had quite a bit of port work on the heads and intake, 15-1 compression on alcohol, with a pretty aggressive cam.

Curtis

[jreiley]

If the dollars are basically the same to buy a new top end, I would think the 18degree is the way to go.

[ccperf721p]

If you are already planning on spending the money, might want to consider a 15 degree setup.

[jreiley]

Don't the 12,15 and 18 degree heads use the same intake and exhaust.

[cncmotorsports]

Don't the 12,15 and 18 degree heads use the same intake and exhaust.
12, 15 and 18 degree take the same intake
700 HP is easy with either 23 degree or 18 degree

[zipper06]

Don't the 12,15 and 18 degree heads use the same intake and exhaust.
12, 15 and 18 degree take the same intake
700 HP is easy with either 23 degree or 18 degree

I respectfully disagree, it's not easy to make 700 HP with 23* heads without spending a ton of money. (why don't you tell us how much you get for a 23* head motor making 700 HP guarenteed/dyno'ed. without additaves/nitrous) Exceptionly/good 23* heads flow maybe 340 CFM. Good 18* heads flow 400 CFM plus, with a 434" it's possible to make 800HP plus with 18* heads for less than $10,000.00 without additaves,
Carb to pan.

JMO

Zip.

[curtisreed]

Don't the 12,15 and 18 degree heads use the same intake and exhaust.
12, 15 and 18 degree take the same intake
700 HP is easy with either 23 degree or 18 degree

I'm with Zip on this. 700hp with 23° heads is not "easy". If it were that easy for you guys I would be seeing a lot of CNCmotorsports sbc motors out there, because you guys could sell them cheap, and hearing a lot of buzz about them. Or at the very least you would be selling quite a few of those 23° heads you are using to do it. Not saying it can't be done just saying it ain't easy.

Curtis

[jreiley]

Pretty much decided to go the 15/18 route. Not being totally sure what I need to look for other than heads and intake, what else special do I need to look for?

[curtisreed]

Headers, and pistons are different.

[jreiley]

Pistons I wasn't aware of. Can the flanges the header's are welded to be changed to give the correct angle, or just buy new ones? What about the valve train?

[ccperf721p]

Valve train will need to be a shaft setup with offset lifters, custom length pushrods.

What will need to be done to the headers depends on the heads you choose. A spreadport exhaust will need the middle tubes positioned a little farther away from each other. Different flanges can be welded on.

[zipper06]

:) ccperf721p,
You beat me too it, we must have been typing at the same time,
Shaft rockers are also different some take .250 offset intake rockers, requiring a .180 or .200 offset intake roller lifters. I've got a set of Brodix 10's RP,FP's 23* spredports that take the .250 offset rockers and lifters. I bought the T&D rocker from Randy Roberts with the mud truck, that he had on his 18* heads. I'm not sure that all 18* heads require the use of offset lifters. I think this engine will make about 750 HP with injection on alcohol.
I've got a set of Lemon 2"X2 1/8" with 4" collectors that are Malibu specific, but they weren't cheap by any means.

JMO

Zip.

[jreiley]

I've looked at Lemon headers, and your right, they are not cheap. The car all this is going into is a 85 Camaro.

[JEFF69Z28]

I've looked at Lemon headers, and your right, they are not cheap. The car all this is going into is a 85 Camaro.
HIS HATS ARE EXSPENSIVE..I BROUGHT ONE FOR 1600 DOLLARS AND HE GAVE ME THE HEADERS FREE....LOL

[zipper06]

I could not afford those prices, but i really lucked out. There was police officer in Lansing Mi. who parterned with another person, his motor the officers car. The headers were never ran but installed. They parted company and the cop had them on RJ for $400.00, i got in contact with him and says hey i just put them on Ebay, starting bid $350.00. had 8 egt bungs, all the whisles and bells.
I was the only bidder, because they were made for a 1980 Malibu same as my car, one of the best deals i ever got in my life. He sent me the original bill from Lemons and it said $1350.00, plus bungs.

Zip.

[wmeabates]

Jreiley,I have an 18 deg. head motor in a 83 camaro,same as your 85.I have edelbrock victor 18 heads,lemons headers 2 in. pipe 3.5 col.t&d rockers .550 intake .170 exhaust offsets,.180 offset lifters,18 deg. pistons. Stock body with a cage,stock type suspension,10 in.slick.Best-1.36 60,6.15 112 1/8 9.67 140 1/4.Street legal antique plate car.Good luck with yours.Bill Bates.

[jreiley]

Hope mine will run as well as yours. Thanks............

[cncmotorsports]

Don't the 12,15 and 18 degree heads use the same intake and exhaust.
12, 15 and 18 degree take the same intake
700 HP is easy with either 23 degree or 18 degree

I respectfully disagree, it's not easy to make 700 HP with 23* heads without spending a ton of money. (why don't you tell us how much you get for a 23* head motor making 700 HP guarenteed/dyno'ed. without additaves/nitrous) Exceptionly/good 23* heads flow maybe 340 CFM. Good 18* heads flow 400 CFM plus, with a 434" it's possible to make 800HP plus with 18* heads for less than $10,000.00 without additaves,
Carb to pan.

JMO

Zip.

Here is our 427, 759 HP
http://www.cnc-motorsports.com/product.asp?ProdID=29625&CtgID=29564

I will agree 18 degree will make more power, but unless you plan on buying used parts, $10,000 is a tight budget carb to pan.

Just saying 23 degree heads can make 700 plus horsepower.

[jmarksdragster]

I'd be curious to see the UN-corrected dyno #'s on that engine.

[curtisreed]

I'd be curious to see the UN-corrected dyno #'s on that engine.

I started to say something about that but deleted it. :roll: :roll:

Curtis

[yedister]

Don't the 12,15 and 18 degree heads use the same intake and exhaust.
12, 15 and 18 degree take the same intake
700 HP is easy with either 23 degree or 18 degree

I'm with Zip on this. 700hp with 23° heads is not "easy". If it were that easy for you guys I would be seeing a lot of CNCmotorsports sbc motors out there, because you guys could sell them cheap, and hearing a lot of buzz about them. Or at the very least you would be selling quite a few of those 23° heads you are using to do it. Not saying it can't be done just saying it ain't easy.

Curtis
If your end goal is 700 horsepower and you will never want to get more power, then a 23 degree will be expensive, if a chance exit that you will want more than that in the future, then 15 degree will be the ticket. Initial cost could be higher but, the power potential is far greater. Post your question on this forum http://www.yellowbullet.com/forum/forumdisplay.php?f=14 also if you search the post you will find a wealth of information.

Yedi

[TheRabbit]

This part was edited after I saw Todds post deleted when I posted mine.

Todd, I've posted right behind two of your post tonight on different threads and by the time mine posted yours had been deleted.
You do that or somebody else do that?


I ran a BBC with 502 GM block, Eagle 4.25 crank (548ci), GRP rods, JE pistons 13.8 - 1, world products heads (not the best choice, but Curtis at RFD got 399 cfm out of one and 400 out of the other head), Comp cam, and a vacuum pump and made 868hp. Don't spend as much as I did on the heads, use eagle H beam rods and you could be at 700hp no problem within a decent budget. My motor ran for over two hard racing seasons no problems.

[Tod74]

I deleted it after deciding it was off topic .


I suggested a 540-565 BBC based on EAGLE OR OHIO parts and a merlin or Dart block. 700-800 HP RANGE EASY for 10-12 k.Buy box stock heads from any of the good manufacturers and buy all the parts from a jegs catalog.

No Fancy high maintenance valve train. A big HP small block is very cool but they are more sophisticated and require more maintenance and know how.

any decent gearhead can maintain and tune an engine like I described

[TheRabbit]

Gottcha. I saw it and replied to your post then it was gone.