switching gm to dart

[the pollinator]

i currently run the double humps on my 355 with 220 dome pistons roller cam and alot of head work done to them with a stock victor jr intake. by switching to the dart iron eagle 64cc 215 runner heads and the dart iron eagle single plane intake what amount of horse power or advantage are we talking about?

[want-a-be]

have them decked to 60ccs to bump the compression. You should be able to make over 500hp pretty easy. No matter how much porting your old heads have to them they will never be as good as the Darts your looking at. Depending on your target RPM you might consider the 200s though.

Thanks, Don

[lun40119]

What cam are we talking about????????

[Awesome Bill]

I should of said if your running a street car or a heavy car, your larger head will not always produce more power. Your getting about 55 more cc's of intake volume. You will not like it if you DO NOT CHANGE a ton of stuff.

That stuff being converter, cam, push rods, even some times ignition has to be adjusted for the loss of bottom end power and you may even run slower! Yeah, kill the bottom end really good so the engine won't leave, it won't pull hard threw the shifts and will be a flat dog because the head is to big.

215 on a very well prepped 350 would need somewhere around 8000-8400 rpm to work WELL! Little engine, slow piston speed, huge head, it will not run well. The carb won't have signal worth a dime and it will be very hard to jet let alone not make any torque. Just Be careful how large you go. I have some old double humps getting it done out there with 383 engines. So its not the size of the ship but how she cuts the water. Air speed has a ton to do with performance, more so than runner size, and when you get them both where they need to be for cubic inches, it will fly.

You can not pay any attention to stock car guys who run in the dirt especially the ones who can't drive or are learning to drive. Everything you give them feels good and most of them could not drive a pencil threw a wet tissue and never get any better. There are very good drivers out there and can win. That is why when Ronnie Tobias, Carl Davis, car owner and manager, got together with me and wanted to run my engines, I told him to just let me build them and you'll see Ronnie lap the field. I am no stranger to roundy rounders and just quit doing those engines because I needed a change. So I speak with a ton of wisdom threw trial and error when I give advise.

I can assure you we did not have any thing close to 190 cc runners in 1994-95-96 and we used the old bowtie steel heads untouched. We could only do bowl work 1 inch from the seat and these were standard tri track rules.

This was an 8.8-1 engine, we were allowed 9:1, and we could use any intake and any camshaft. Everything else was spec. Ronnie won the majority of the races and we were pulled down every time after the races to see if we were cheating and we had to start dead last every time because of the way points were set up, the tear downs was because of who I am. We never failed tech and we ran away with the championship so bad we did not have to run the last 3 races. So when someone shows how child like he or she can be on a board where we are trying to give and receive information, try not to pay attention to wannabees, I apologize to everyone for having to put up with this type of behavior and will see about it with Dart about correcting it.

[want-a-be]

toning down:p

[Dart Vader]

There are more than a few people on these boards who have some expertise putting engines together and tuning them.
I encourage as many of them as possible to give their take on any particular question, as this will hopefully allow the more successful techniques to emerge as such down the road and encourage the best possible environment for people to get really good input on their setup.
Acting like everything you say is infallible doesn't get anyone anywhere.

Want-a-be: Tone it down and try to support your point of view with information as much as possible, we want posts that other users can gain some knowledge from.

Awesome Bill: Try not to act like your the only one here with engine building experience. You may even pick up some useful knowledge yourself from some of the forum members.

I'm not trying to be a nazi, I always try to make it clear that I encourage people who have dissenting opinions to express them, I believe that it encourages learning and the spread of knowledge.

Remember, no one has a monopoly on engine building advice here... Keep it civil.

[lun40119]

I have tried the larger runner heads on the smaller cube engine.....I was successful in gaining hp and torque in every rpm from 3500-7500. The only issue that I had was idle quality with the lower idle vaccuum signal. A simple initial timing adjustment and a recurve cured it for me. I was running an Iron head from World. Switched to the aluminum head from dart and am EXTREMELY HAPPY :D

I sent you a pm with the number comparisons.

[the pollinator]

its for a circle track car with eagle forged crank 6.0 eagle rods srp dome pistons bowtie 355 block and a flat tappet cam 3500-7600

[lun40119]

Your original question had something to do with how much of an advantage you would have by switching from the factory gm head to the larger Dart head. I sent you a pm with my number comparisons for your operating rpm. However my comparison is from a set of World 200cc heads to the 215 Pro 1. I would guess you could even see more of a gain. If you would like to hear the real world difference on the dyno, I would be more than happy to send you the links. They are on youtube. There are lots of videos of engines screaming on dynos. Some with crazy sweeps that sound like they are the best thing since swiss cheese. My pulls are in the 300-500 range. I don't claim to know half as much as the PROS on this forum.........I am basing my opinions off of hard concrete evidence. My engine combo is blowing right through the off the shelf converter I have in the car right now. Unfortunately, I am working with MY money, and I cant order the new one just yet..........however rest assured when it is in the car........MY LITTLE TINY STREET DRIVEN TURD WILL BE QUICKER.

[Scott McMullen]

My Last Combo I am In the Racers Gallery.
355 ci
GM Steel Crank
6 in CAT Rods
12.5 to 1 Compression with a Lunati Taylor Nitrous Piston
Milodon Oil Pan with Diamond stripper windage tray
Moroso Oil Pump
Camshaft Innovations Solid roller .660 Lift 258-262 @ .50
Dart Pro 1's bought as Seconds AS IS From Swap Meet Brand New just bad casting Flaws Dart would not sell them as new so I got them for a Great Deal oh and BTW they Are 215's
Box Stock Victor Jr Intake
Pro Systems 780 cfm Carb with all the proper vacuum Ports
1 3/4 headders
MSD 6 Series Ignition
4500 Stall convertor
Th350
All of this in a 3625 lbs (Milan Dragways Scales) through 2 1/2 Inch Exhaust with V-Force Mufflers and Full tailpipes.
1.57 sixty
11.46 1/4
118.90 mph
Street Driven was driven to the track

[want-a-be]

have them decked to 60ccs to bump the compression. You should be able to make over 500hp pretty easy. No matter how much porting your old heads have to them they will never be as good as the Darts your looking at. 215s ought to do you fine. If you're even remotely concerned then take the conservative route and do the 200s.

Good racing this year.

Thanks, Don :cool:

WCRE

[Awesome Bill]

That is not to bad, your weight and hp factor is around 430hp and maybe 10% for a throw away being your real street. Your carb is a vacuum secondary?

[Awesome Bill]

The 500 range is our base line that we also use. I use around 200 and capture it every 50 rpm when looking for small changes in areas we are hoping to pick up. The dyno sessions your talking about are for the general public that have never seen them. We only use the pretty pulls to keep down on the time used on the site. We were one of the first, if not the first to start posting our customers engines and has become a very nice addition for everyone. My son is very good at getting that stuff out so people can see it. So don't be hating because of some nice looking video's that give people a nice view of what a dyno does. They don't have to understand all the technical very fine points of what condtions we have to duplicate to be dead on, they just want to hear and feel the power. Kinda like watching drag racing on TV.

I know all about some people claims of their dyno #'s that are not there @ the track and they always blame it on something. When your down 100-150 hp, as most are, thats when it becomes a problem. Most people don't even understand what even goes into dyno testing correctly. Every dyno in the world should be within 5% given correction factors and real driver error. Those load sensors, air temp, humidity, barometric pressure, grains of water per pound are all math that can be calculated. When my dyno #'s are within 1-2% at the track, where it counts, that is all that matters. The nice fast pulls get the point across. Hopefully it motivates to have their stuff tested by a reputable dyno facility that has a service for such guys wanting to know the real deal.

[lun40119]

Agreed.... thanks for clearing that up.