j69camz28

Hey guys -- I'm going to be building a new engine starting in late Jan or early Feb. Its gonna be a 427cu small block. Here is what I'm thinking so far :

World Products 'Motown' block w/ splayed caps.

Forged Crank, Forged H Beam Rods, Forged Pistons, approx 10 - 10.5 compression. (want it to run on pump gas on the street)

AFR 210 "Race" Heads (the competion heads flow a little better, but not $500 more better)

Comp Cams mechanical roller - 248/254 .576/.582--but Im going with 1.6 rockers(shaft) which makes the lift .614/.621

Edelbrock Victor Jr

Holley 850cfm double pumper

MSD billet dist. / MSD Digital 6

Hooker Super Comp 1 3/4" prim. 3" coll. headers

What do you think of what I've come up with so far? Nothing is bought yet, so I can adjust the combo still. I'm looking for this thing to run anywhere from 10.50-10.80 on the engine. I will spray it down the road. It will be going in my 69 Camaro that weighs approx 3100, has a Strange S-60 rearendw/ 3.73s, TH350 w/3000 TCI convertor, MT Drag Radials. The car has been as quick as 11.01 @ 118.55 on a 100hp shot with my much milder 406sbc(11.89 @ 112.65 on the engine). Thoughts, suggestions? I

Trevor86TA

What size headers are you thinking?

Are you going to put more converter in it?

You could likely go with more compression - especially if you put more cam into it.

84firebird383

I think you will will hit your goals no problem with that combo. That cam is almost identical to mine,I have Brodix track 1's about 10.7:1 for compression 383 cubes, 3.73 gears with a the 350 and TCI super street fighter converter and I run low 11.s @ over 120MPH in a full weight street car that has zero suspension or chassis mods.The extra 44 cubes and a better chassis should easily have you in the mid 10s.

IHI

iTrader: (1)

Sounds like a very good combo, and not to be a nay sayer, but I had 3 very close racing buddies jump from nice 406cid combo's upto 420 and 434's thinking they were going to gain ET with more cubes, granted they bolted on everything from their 406's on top and changed cam to go with larger cid, but once tuned expetations were not met. While the extra cubic inch looks good on paper and in theory, when only jumping up an average of 20cid it does not generate as much as one would think it would.

Biggest thing holding back power when going big inch is the heads obviously, since they are the limiting factor in air flow. The 210's are a good head, but stepping up to a 220 or 227 would be the wiser choice with this combination to really maximize what you laying out. The 210's can be worked over to provide over 300cfm of flow from the base set your starting with, but a typical clean up port job starts about $500 from a place that knows what they're doing and flows during process to see gains are being made. Once you get past the typical clean up and get into really hogging them out to the max, $1000 is about the normal rate from a good shop/guy. But then your in the boat where it would'v been cheaper to buy the bigger head initally...same situation I'm in right now myself with mine and reason shop advised me after I dropped heads off initally to get checked out to run them as they were and see how I like them since they could easily get another 15-20cfm from them with a clean up which equates to approx .1-.2 on the track

From experience, give Bullet a call for your cam. http://www.bulletcams.com/ I can say this based off the truck I run has a higher compression 383, shaft rockers, cam specs are identical to mine as far as actual duration, and LSA but lift is a hellava lot higher, truck is also 800lbs lighter than I am but only running consistantly .3 faster than me. I actually laid down higher tq at the wheels than the truck did on the engine dyno. Same goes true with my brother in laws car, another comp cam with outragious spring eating specs and for what it is, it does'nt run what you'd think it should. I got feedback from many racers before talking to Bullet and I heard nothing but great things and I also can say nothing but good things...more with less. Many of the guys that run the place are former cam designers that got the other players in the cam business up and running with the newer dual pattern cams and grinds...just my opinion, but I'd never have a comp in any of my engines based off everything i've seen-too much advertising/hype and not enough performance

You can safely go upto a minimum .630 total lift with no spring problems on the street so long as springs are good quality, so keep that in mind as well. I know my grind coupled with a vacuum can provides great pwr brakes, and drives as easily on the road as my dialy driver truck-exactly what I was after when laying out my combination.

If sticking with that duration you'll need a good 4500 convertor and the right tire/rear gear combination to work right, otherwise your shorting yourself. Header size should work well with given cam specs, if going to a larger druation it will raise powerband and thus require exhaust to exit a little better so jumping to a 1 7/8" pri and 3.5" collector would be better off, but for now it should work fine.

Overall, with no more than you weigh you should easily achieve you goal of high mid second 10's, just know you could get below that goal pretty easily for the same or tiny bit more cash lay out...and still be streetable!!

ross

I have a 434 on the stand I picked a set of dart cnc 227 heads for it but when I was almost done with it I found what I think is a better set of heads.I just ordered a set of 260cc raised runner heads. I want to go bottom 10s on pump gas and then spray it with a 300 hp kit. From the people I've talked to you just cant get to big of a head on the big inch motors.Also to get the comp. you want you're pistons are going to be very weak if you want to run nitrous. Try and use a 5.85 long rod and a .043 top ring. And for what its worth I have flowed two set of the AFR 210 race heads both were very disappointed flowed somewhere around 285s cfm on the intake. I had a pair of AFR 195 heads that flowed almost that number 277 cfm intake

itsjustabird

iTrader: (1)

My opinion is run the larger afr's use a supervictor intake run a cam with more duration than what youve mentioned and keep the lift in the 630-640 range (unless the heads need more lift) and run right at 11.1 comp. and you should make very good power.

five7kid

iTrader: (14)

I've heard a similar story as IHI. Guy at the track with a tricked-out '89 Vette had a stock-block 434 that broke through a cylinder wall (they're pretty thin). He rebuilt it with the Motown block, which was fairly new at the time. The shop doing it for him (his sponsor, actually) screwed up and ordered the 400 block. But, in the 3 seasons since, he's running faster now with it than he was with the 434. Of course, that's with other changes, but the point being the cubes aren't the final word.

MrDude_1

above everything else, you're better off going to a better head design with a 18 or 15 degree angle..

you would go faster doing that then adding cubes..
that does throw a couple monkey wrenches in, but nothing you cant buy.
you're already planning on big cash for the valvetrain (shaft rockers arnt cheap) so thats no real issue.
piston choice might change with the diffrent valve angle.
header choice will most likely change.. but they make EVERYTHING for 1stgen camaros, so its not a big deal.
of course, the intake manifold has to change to match the heads.

but the overall result is a motor that flows much more air then any 23* would....

Free Bird

iTrader: (1)

I agree, it's almost impossible to keep up w/ a 18-15* set up unless you're running the same. But they like a lot more compression, and a bigger cam.

MrDude_1

no, they're just better heads. you dont NEED more compression.. you dont NEED a bigger cam. it just so happens that a majority of the people spending the dough for the heads also go all out on everything else.

what happens when you put extremely well flowing heads like thoes on a otherwise mild motor?

you end up with a very civil motor thats making far more power then you would expect. this is how the LSx engines, new hemis, and even the 3 valve fords are making the big HP numbers..(big for OEM..)

once you have that great airflow, it helps everywhere.

daverr

iTrader: (1)

Im in middle of building up a 426 sbc dart block.I decided not use a 23* head ,because they dont flow enough for a big inch smallblock and therefor would be waste to use on a big inch motor.So i went with a set of 18* heads.

U almost have to run high compression with these heads.they come with very small chambers.I am going to run a big cam with this motor.Why wouldnt i , the heads flow well into the .800 lift range.

I know this setup is high dollar but is well worth it(i hope).Using a 23* head nowadays is waste for na applications.there alot of better heads out there, such as RI,18,15,sb2 etc.

goodluck with your project.

mw66nova

iTrader: (13)

how would the 18-15* heads perform on say...a regular 350...

j69camz28

Thanks for all the input, guys. I will look into a 18* head setup. IHI, you have (had) a setup similair to what I was thinking. You seem to think I could hit close to 10.50s with the 23* head setup. This is my goal, and I can spray it into the 9s from there. But I also see your point about going with the 18* head to begin with. I will study it out some more. Again, thanks guys...

ross

If your goal is 10.50s with motor you can do it with a set of 23 deg.dart ,afr,or brodix 227 cnc heads. The darts I have some info on them they will use standard rocker arms and lifters. And on the flow bench I use they flow 305 on the intake side out of the box. With a 400-434 ci motor and 11 to 11.5 to 1 comp and a solid roller with around 260 deg of duration at .050 You should make your #s

IHI

iTrader: (1)

The combination your considering is very affordable, will last a long time with minimal stress to parts and hit your ET goal no problem, and all easily attainable with 23* stuff-which in the grand scheme of things is very affordable and easy to build/set-up.

I agree with the superior flow of the 18, 15, and 12* stuff, but then your opening up a whole nother can of worms in itself with actual components, thought of components working together to get proper compression-if you were going strictly race and high compression no biggie, but alot more thought goes into a combination using the race only inspired stuff.

Personally I would tweak a few thing in the original idea/post for an overall syncronized drivetrain, but that's me and like I said for the same money you could change up a few things and get more out of it.

10.90streetcar

If you dont think a 23* headed 434 will out run a 23* headed 406 you are mistaken. I took the heads, cam, intake, carb from my 406 and built a 434 and picked up a solid 4 tenths with no other changes. the 406 ran 10.50s the 434 ran 10.0s with a best of 9.97. I am now building a 434 with sb2.2 heads. That should really wake this thing up.

IHI

iTrader: (1)

Not arguing with you, but you've stated .2 were from adding the carb pan and running the dominator as compared the 950HP after the 434 was running good, as I recall you were consistant 10.30-10.20's after the swap and inital tune which supports my original statement of the extra cubes wont gain you a ton. Ur sheeot runs great for a sbc, no doubt but realistically those few extra cubes are not the "ultimate" answer for going alot faster, but in a sport were tenthousandths of a second mean the world, any little bit helps.

jrsfast84

My 2 cents, i sold my buddie a 383" AFR 210 race heads that are hand ported by me, that flow 314 int., 245 ext. at .700, AFR heads like the Edelbrock # 2925, with a 2" spacer, comp.13.5, comp cams- .720- .683 w/1.6 rockers, the car weights 3325lbs. and went in semi good air 10.05 @ 131, th350, 12bolt 4.88,5500 stall, the 383" is a great combo.