I was following Pauldana great build thread of his 427 sbc,it will make some great power.I want to spice up my current 427 sbc also .so I was looking around and found dart short blocks for sale for $3999,at Racing Junk .com . they sell the dart shp ,400,415,and 427 sbc .its a little more for upgrades ,but it is $1500 less then jegs or summit.I need a single plane intake and a roller cam.I can't decide between a hydraulic or solid roller comp cam.

 

Depends on usage and rpm needs.
Everyones got their favs love solids myself.

 

What rpm range do you want to make peak power in? Solid lifter valve train has the sound that i love, but due to keeping my rpm at 6500 rpm or less i opted for the hydraulic. Straub has hydraulic grinds that make power and have the capability to run up to 7200 rpm in a hyraulic roller with the right lifter with out the maintenance of a solid.

 

I want to make peak hp below 6500.I am looking at the comp 288hr and the 294hr .will the solid rollers cam have more lift for more power ?I like the 280 ,or the 286 solid roller grinds.I have a little over 10-1 compression with dart 215 aluminum heads .I use a air pan ,so I can run a taller single plane intake .I feel my rpm air gap would restrict air flow .I like the numbers of the holley strip dominater intake .I would like to try the AFR like Pualdana .

 

I think you could do well with a custom making peak power at 6300 and shifting at 6500, ive got the xe288hr in my 400 and shift ar 6000, sometimes 6200, i got heavy lunati street roller lifters and no rev kit, overall i like the cam but think that if id went with the solid equivelent it would have made more power. Being lazy i didnt want to adjust the valve train a bunch and figuring that my engine would live longer at a max rpm of 6500 rpm hydraulic roller was the choice. Now that 6200 comes so fast in first gear, i kinda regret not going either light weight valve train or solid roller. The thing abought solid roller cams is higher lifts with abought the same duration im running now which means more area under curve and more power. With out researching the 215's id guess that max lift would be around .650" lift and if you could get your cam to that would optimise the heads, which would probably be easier with a solid. I also believe that with the extra stroke and bore that your running a good single plane is a no brainer, im running the rpm air gap and for a while had an open spacer which made the top end scream, but went to a four hole and my bottom end picked up but now its not as fierce on the top end this with 3.08's, ive got a set of 3.55's on the garage floor and figure that when i go back to the open. with all this rambling, the point is with the extra stroke/ torque of the 427 and the port size of the dart 215's an open plane would probably yeild the best results.

 

By saving money on racing junk are the internal pieces inferior?

It was my experience that the 294 cam was kind of wimpy for my 427. I would also stay away from the crappy pot metal Comp Cams and get the billet steel with a sleeved dizzy gear

does the intake port size match up to the Dart 215 port size without mods?

Holley#510-300-25
Strip Dominator Intake Manifold
Small Block Chevy
4500-7600 RPM
Single plane/open plenum
No heat crossover provision
Height: 5.11" front/5.97" rear
Port size: 2.05" tall/1.22" wide
Square flange/4150 carb pad

 

Measure your Dart 215 intake ports. They usually run quite a bit bigger than advertised.

 

Aint that the truth dont know why they stilll do that
Their newer 200s are about 200
180s are over 190
My old 200s were about 220. WTF

 

I know why. Great flow numbers when compared to competitors. They do the same thing on the exhaust side going 10 CC bigger than everybody else to boost flow numbers. They sell a lot of heads to those that compare them on paper and feel they are getting more bang for the buck. This is not the case if you expect and design your build for a specific port size and you get 10% bigger ports than you expected. Been there, done that, was pretty pi$$ed when my intake ports were not even close to matching my heads.

 

We did a buildup with a Dart SHP package for Corvette Enthusiast magazine a couple of years ago. We upgraded to forged crank and pistons and assembled it with as cast Dart 200cc heads. Took everthing out of the box and assembled it without any fancy stuff. We used a custom solid roller cam from Comp.

We tested it with a 2x4 WCFB carb setup and a Dart dual plane and a Weiand single plane using a 750 Holley.

As far as quality, everything fit as expected and it's been running fine with no issues at all.


JIM

 

I think people get way too excited about specific port cc's. It's not about the cc's..it's where those cc's are within the port.

You could have a hogged out bowl way out of proportion to the throat area that would kill flow a lot more than if the short turn or runner was opened up and matched to the intake runner correctly.

A "good" set of "big" heads will still make more TQ than most think....while at the same time a poor set of "big" heads may still not make the big top end power. Same thing holds true for "small" heads....they may not do that well down low..yet some of them do well up top.

Look for combinations that are proven to do what you need rather than worry about a specific airflow number or head cc.

JIM

 

You know Jim, ive seen you post this other places and haven't been able to get the link you usually post with it to show me the combo. Can you post the rest of the build.
Thanks in advance Blue

 

When they switched to Auto Enthusiast most of the older Corvette Enthusiast stuff was lost on-line.

It used forged flat tops and 64cc heads to end up with 11.0 compression. The heads were out of the box Dart 200 cc heads. The point of the build was to take everything out of the boxes and bolt it together in a weekend and strap it to the dyno. I didn't do any hand massaging at all...and that's tough for me!

I knew it would ultimately end up with the 2x4's and WCFB's. It went into an original 283/270 car and the original engine was stored. This one was disguised to make it look as stock as possible. That poor old intake was ported to within an inch of it's life. We'd have taken out more but the integrity of the casting would have been compromised. Even after porting it was obvious it was too small to feed 400 cubes...and the dyno sheets show that.

The cam was selected after lengthy discussions with Billy Godbold who is Comp Cams head designer. We spent a lot of time discussing "where" the restriction was. The carbs(no), the ports (no)...the intake (yes). Same discussion on exhaust...was restriction in the head (no)...the headers (no)..the factory manifolds (yes)...the exhaust pipes (yes)...the mufflers (yes). Spec'ing the cam a little differently allows you to play with the compromises. You do the best you can...and in this case it worked pretty well when the restrictions were lifted by adding better intakes/carb.

You have to think a little of the differences in a NASCAR type motor with killer heads and a tiny 390 cfm carb...or a circle track motor with weak heads and a 2BBL. Both are restricted on the intake side...but they both need a different cam based on where the restriction is.

In this case we used a 248/248@.050 on a 109 LSA cam. It used the intake lobes from the XR286 cam on both intake and exhaust with 1.6/1.5 Comp rockers to create .614/.576 lift. This was a good bit of duration but we had to add some to deal with the restriction issues. If running with either of the "good" intakes and headers it would have likely had less duration on both sides with a 4-6* split and a tighter LSA. When it was done it made power right where we wanted it to.

Our shortblock came with a .021" deck and with the .039" gasket made for .060" total quench which is more than I would have preferred..but it turned out OK with a final 11.0 compression. It works fine on 93 octane in Houston heat.

I highly recommend ordering the forged pistons on any engine like this. I would also suggest upgrading to 7/16" rocker studs if using a solid roller in any smallblock.

I used a stock Melling oil pump with a high pressure spring. The oil pan was a stock GM passenger car pan to keep stock look.Not even a "good" one with baffles...just a plain pan. Certainly a better pan would have helped power even more.

Here's a video of when we fired it up on the test stand to give you an idea of what it sounds like with open pipes and manifolds.

JIM

 

Thanks for sharing.

 

Sure, if you have any other questions about it just let me know.

JIM

 

thanks guys for all the great input .I will start researching intake runner dimensions.I will get a intake that can port matched to my current heads .I should flow the heads to help pick a cam ,I mite consider having them ported first .what cfm should I be looking for at .500 and .600 lift ?.I want a cam that will create a pump gas friendly DCR .I would like 11" of vacuum or more .with a 3.875 crank ,my piston speed should be slower then that of a 4" stroke sbc 427 right ?

 

If you're thinking about porting heads....yu might ck with Chad Spier Racing heads. He's got some neat smallblock packages or the alternative is to go for some nice CNC ones out of the box.

JIM

 

I believe valley heads does a good job too.