Thread: how much hp

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i have a 355ci just got some dart iron eagle platinum 215 heads with 2.05 1.60 valves. holley street dominator intake 1" open carb spacer holley 650dp eagle cast crank stock rods flatop pistons 4 valve reliefs 1.5 roller rockers 1 5/8 headman long tube headers 488/510 lift cam 234/244 duration at .50 114 lsa. turbo 400 3500 stall B@m shift kit 3.73 gears. any guesses on power and compression not zero decked looking to run low 12's in my 3200# 87 camaro. thinking about geting a newer cam. thanks oh and do i need to get longer pushrods

What is your goal? Is this a strip car, a street cruiser, or what? We need to know to give you some accurate feedback.

I have no advice to share with you, but wanted to Welcome you to here. You will get good advice from others here, so keep checking and asking.

Jack

its going to be a strip car with weekend driving

Originally Posted by steve88crx

i have a 355ci just got some dart iron eagle platinum 215 heads with 2.05 1.60 valves. holley street dominator intake 1" open carb spacer holley 650dp eagle cast crank stock rods flatop pistons 4 valve reliefs 1.5 roller rockers 1 5/8 headman long tube headers 488/510 lift cam 234/244 duration at .50 114 lsa. turbo 400 3500 stall B@m shift kit 3.73 gears. any guesses on power and compression not zero decked looking to run low 12's in my 3200# 87 camaro. thinking about geting a newer cam. thanks oh and do i need to get longer pushrods

You have some mismatched components which are going to keep you from realizing your engine's full potential. First of all, those 215 heads are way too big which will cause you to lose lower end and some mid-range torque. There just is not enough cam to utilize that much breathing. And if you go to a bigger cam that would work with those heads, you do not have enough compression to effectively make the big cam work. I would sell those Dart heads and go for the new AFR heads if I were you. Go here and check out the 450 hp 355 sbc: http://airflowresearch.com/chevy_dyno.php. Now that is the kind of matching components you should be looking for. And that engine should give you the kind of performance you desire.

Or... if you haven't bolted the Dart heads on yet, you can put those back in the box and exchange them for the 200cc iron eagles or even the 180's might be even better for the street. The 200's would be good if you wanted to stroke it to a 383 later on down the road. As for horsepower, I figure you'll be right around 450hp with around 10-1 compression. You'll make more torque and a broader powerband with the smaller heads.

With your block being standard decked your compression should be about 9.5 to 1. Zero decking it will bring it to 10 to 1.

Yup, way more head then you would ever want on the street. Something in the 180 or 190 range would be much better suited to street use on a mild engine.

would anybody know the pushrod length and would thinner head gaskets raise the compression up.

It's always best to check your pushrod length with a pushrod length checker... Then you know you will have the correct length pushrods, though I don't really see anything in your setup that would require special length pushrods. Hopefully some of the chebbie guys will jump in here, but on any engine it is best to check pushrod length with the correct tool rather then guess.... A thinner head gasket would be a nominal increase in compression... You probably wouldn't want to be a lot higher then 9.5 with the cast iron heads and be able to run on pump gas. With aluminum heads, you can generally run about 1 point higher....

well the reason i got those heads is beacuse later on its going to be a drag only car and dont want to go through the hassle of geting new heads. but befor i put it together im thinking of geting a vic jr and a bigger cam like a 550 lift and 250 .50 duration

Well, with the setup you have now, it's going to be a pooch for mid range power and torque. Heads that size are made for zinging the engine to 8500, or a very large cube stroker running on the track only.... The way i see, a Victor Jr. is only going to compound the problem and take away more mid and low range power.... Dual purpose engines are a comprimise. You either wind up with way too much for the street, or not near enough for the track....

Even as an all out drag car, those heads are going to be too large unless you really build a screamer, then the cast crank isn't going to be up to the task..... I've run some very strong big inch strokers, 408 to 420, with roller cams, steel cranks, h beam rods, and never with a head bigger then 190...... That 355 would be a lot stronger, even with the bigger cam, with a set of 180's......

do you think i would be able tpo hit the 12's with the combo i have now.

run it. u will be close to the 12's i had an 82 chevy pickup that i street stripped 9.5:1 dart 230 heads 2.08 valves, #3600 12.50,s oh and a custom roller cam from comp

Originally Posted by steve88crx

would anybody know the pushrod length and would thinner head gaskets raise the compression up.

Your head gasket choice should be based on getting the correct amount of quench. If you have a stock block, you can assume the pistons are approximately .025 down in the hole, so you should look for a gasket that will put the quench at between .035 and .045 ideally. I would look for one of those thin .019 or .020 gaskets, and it will put you right on the money.