Thread: choosing a cam w/ car.

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I am building a 355 SBC.

I have 10:1 forged Speed Pro pistons.

200 cc heart shaped alum heads, w/202 160 valves, & 63 cc chamber.

1.6:1 roller rockers

Rhoads lifters to help with manifold vacc at idel & power brakes.
Should make the cam SMALLER at low rps also.

Forged Scat crank w/ stock stroke.

Edelbrock RPM amnifold.

Holley square bore 750 dual feed vacc secondary carb. (Wish I knw the model #).

It will have stock 1988 corvette exhaust manifolds (because of clearance issues) into a 2.5" Flowmaster 40 muffler for a Camaro (two one in two out).

My car is a 2500# Pontica Fiero GT w/ manual 5spd.

Running 17" wheels & 40 series rubber.

I want to get in the 450 hp range & have it come in around 2500 -3K range. I do not want a lot of low end torque as it will explode my transaxle.

This will be a weekend only car, no drags.

I am thinking of Comp cams X-Treme energy 12-250-3 (from PAW book) spec are 264/296 aadvertised deg, 240/246 @ .050, .507/.510 Lift w/ 100 deg lobe speration.

Will this combo seem okay??

You should have enough compression to run that cam, it is really lopey, might not be good for a street car, it ain't gonna idle well or have functioning power brakes ( not enough vac to run the power booster ). your going to run in the need for higher gears and a 2,500 stall converter at least if you want it to pull itself out of the hole, otherwise it will be doggy out of the hole. I'd recomend CRN-113802 which is a cam operates in 2,500-5,500 range 222*/234* .467"/.494" it is a crane powermax cam, that is a Summit number. the 1.6 rockers are going to make the cam slightly hotter. the lifters will help make it slightly smaller but not much at all.

Originally posted by 1986GT V8 Fiero
I am building a 355 SBC.

I have 10:1 forged Speed Pro pistons.

200 cc heart shaped alum heads, w/202 160 valves, & 63 cc chamber.

1.6:1 roller rockers

Rhoads lifters to help with manifold vacc at idel & power brakes.
Should make the cam SMALLER at low rps also.

Forged Scat crank w/ stock stroke.

Edelbrock RPM amnifold.

Holley square bore 750 dual feed vacc secondary carb. (Wish I knw the model #).

It will have stock 1988 corvette exhaust manifolds (because of clearance issues) into a 2.5" Flowmaster 40 muffler for a Camaro (two one in two out).

My car is a 2500# Pontica Fiero GT w/ manual 5spd.

Running 17" wheels & 40 series rubber.

I want to get in the 450 hp range & have it come in around 2500 -3K range. I do not want a lot of low end torque as it will explode my transaxle.

This will be a weekend only car, no drags.

I am thinking of Comp cams X-Treme energy 12-250-3 (from PAW book) spec are 264/296 aadvertised deg, 240/246 @ .050, .507/.510 Lift w/ 100 deg lobe speration.

Will this combo seem okay??

To much head.Try a 180 cc head.

Only because I was looking at doing something similar, I'd have gone with 3.8L supercharged engine. West Coast Fiero sells all kinds of conversion items for these cars. The 3.8L can make the 450 HP that your looking for and take up less space. The Getrag trans will take the torque and should work with the Chev V-8.

I am running a 383 SBC in my 88 Fiero GT. I have a complete build up site located at 64.17.190.253 I have only put about 400 miles on the motor so far but it did dyno 416 horepower to the rear wheels using a Getrag 5 speed. That is well into your desired 450 horsepower desire. building a SBC to that level is not that hard nowadays, use a David Vizard book as a guide and follow his information. All the parts you have so far are looking good as far as producing that much power, the cam is pretty much a personal choice, I still have the tendency to over-cam my SBC engines, after 40 years. Maybe some day I will learn to tone it down.

My cam is a "292", regrind to match the original 292 cam ramps on the 350/375 horse 350's. It is a bit more duration than necessary for the street but the five speed helps keep the rpm up to take advantage of the strong duration. Also the increased cubic inches helps bring up the hp.

You might get a piece of desktop software and play with various cam designs to get a better handle on how much horepower each cam will allow you to crank out of the SBC.

Good luck with your project.

Andy

edited to correct web site location. It works now

Originally posted by Andy Keene
I am running a 383 SBC in my 88 Fiero GT. I have a complete build up site located at www.64.17.190.253 I have only put about 400 miles on the motor so far but it did dyno 416 horepower to the rear wheels using a Getrag 5 speed. That is well into your desired 450 horsepower desire. building a SBC to that level is not that hard nowadays, use a David Vizard book as a guide and follow his information. All the parts you have so far are looking good as far as producing that much power, the cam is pretty much a personal choice, I still have the tendency to over-cam my SBC engines, after 40 years. Maybe some day I will learn to tone it down.

My cam is a "292", regrind to match the original 292 cam ramps on the 350/375 horse 350's. It is a bit more duration than necessary for the street but the five speed helps keep the rpm up to take advantage of the strong duration. Also the increased cubic inches helps bring up the hp.

You might get a piece of desktop software and play with various cam designs to get a better handle on how much horepower each cam will allow you to crank out of the SBC.

Good luck with your project.

Andy

Your linky no worky!!!

Originally posted by 1986GT V8 Fiero
I am building a 355 SBC.

I have 10:1 forged Speed Pro pistons.

200 cc heart shaped alum heads, w/202 160 valves, & 63 cc chamber.

1.6:1 roller rockers

Rhoads lifters to help with manifold vacc at idel & power brakes.
Should make the cam SMALLER at low rps also.

Forged Scat crank w/ stock stroke.

Edelbrock RPM amnifold.

Holley square bore 750 dual feed vacc secondary carb. (Wish I knw the model #).

It will have stock 1988 corvette exhaust manifolds (because of clearance issues) into a 2.5" Flowmaster 40 muffler for a Camaro (two one in two out).

My car is a 2500# Pontica Fiero GT w/ manual 5spd.

Running 17" wheels & 40 series rubber.

I want to get in the 450 hp range & have it come in around 2500 -3K range. I do not want a lot of low end torque as it will explode my transaxle.

This will be a weekend only car, no drags.

I am thinking of Comp cams X-Treme energy 12-250-3 (from PAW book) spec are 264/296 aadvertised deg, 240/246 @ .050, .507/.510 Lift w/ 100 deg lobe speration.

Will this combo seem okay??

put it on a 108LSA, use a adjustable timing gear, install cam straight-up, then try it 4* advance, use performer rpm air-gap
brain storm a new solution on the headers (custom, shorty) play with spacers this will get you close to 400+ hp

Originally posted by 1986GT V8 Fiero
I am building a 355 SBC.

I have 10:1 forged Speed Pro pistons.

200 cc heart shaped alum heads, w/202 160 valves, & 63 cc chamber.

1.6:1 roller rockers

Rhoads lifters to help with manifold vacc at idel & power brakes.
Should make the cam SMALLER at low rps also.

Forged Scat crank w/ stock stroke.

Edelbrock RPM amnifold.

Holley square bore 750 dual feed vacc secondary carb. (Wish I knw the model #).

It will have stock 1988 corvette exhaust manifolds (because of clearance issues) into a 2.5" Flowmaster 40 muffler for a Camaro (two one in two out).

My car is a 2500# Pontica Fiero GT w/ manual 5spd.

Running 17" wheels & 40 series rubber.

I want to get in the 450 hp range & have it come in around 2500 -3K range. I do not want a lot of low end torque as it will explode my transaxle.

This will be a weekend only car, no drags.

I am thinking of Comp cams X-Treme energy 12-250-3 (from PAW book) spec are 264/296 aadvertised deg, 240/246 @ .050, .507/.510 Lift w/ 100 deg lobe speration.

Will this combo seem okay??

This combo. will have very poor throttle response.The heads will pull to 8,000 r.p.m.s. and the cam is done at 6,500.I would look into heads that have a max. port volume of 180 cc.

What heads do you plan on running? The Dart line-up would work very well be it Pro 1 or Iron Eagle. They offer many different sizes and configurations. You can choose the style that best fits your needs off their recommendation charts. Here are a few:

165cc----street/strip performance & towing w/stock engine.
180cc----street performance, max torque/response under 350ci.
200cc----street/strip performance, 327-350, 6000rpm
215cc----serious street/strip perf. 383-400, 7000rpm

Hope this helps. Might can get more info at WWW.DARTHEADS.COM

Originally posted by camaro_fever68
What heads do you plan on running? The Dart line-up would work very well be it Pro 1 or Iron Eagle. They offer many different sizes and configurations. You can choose the style that best fits your needs off their recommendation charts. Here are a few:

165cc----street/strip performance & towing w/stock engine.
180cc----street performance, max torque/response under 350ci.
200cc----street/strip performance, 327-350, 6000rpm
215cc----serious street/strip perf. 383-400, 7000rpm

Hope this helps. Might can get more info at WWW.DARTHEADS.COM

What people forget is a good bowl blend and any port work done also installing larger valves change the flow characteristic's of cylinder heads.I would tend to choose a smaller head for any street car to try and keep the port velocity a little better.After all you won't be lauching the car at 5,000 r.p.m.s at every light.

Originally posted by erik erikson
What people forget is a good bowl blend and any port work done also installing larger valves change the flow characteristic's of cylinder heads.I would tend to choose a smaller head for any street car to try and keep the port velocity a little better.After all you won't be lauching the car at 5,000 r.p.m.s at every light.

Here we go again...........NOT. Let's get together and sue Dart for false advertising or even better yet YOU can design a line of heads because if Dart can't even get their recommendations right they surely can't build heads right.

Also this guy well states he don't want eye pulling bottom end in his post. Anyway, I am almost certain that this combo will produce more torque than a stock 350 @ any given RPM. This is not going in a 4x4 or a stepside truck or being used to pull a camper on the highway. You have to spec a engine to it's use. A 2500lb car and a manual trans does not need to pull a house and I would really hope that all the modifying to set a small block in it was for the purpose of speed, not tractor pulls. PEACE OUT

Originally posted by camaro_fever68
Here we go again...........NOT. Let's get together and sue Dart for false advertising or even better yet YOU can design a line of heads because if Dart can't even get their recommendations right they surely can't build heads right.

Also this guy well states he don't want eye pulling bottom end in his post. Anyway, I am almost certain that this combo will produce more torque than a stock 350 @ any given RPM. This is not going in a 4x4 or a stepside truck or being used to pull a camper on the highway. You have to spec a engine to it's use. A 2500lb car and a manual trans does not need to pull a house and I would really hope that all the modifying to set a small block in it was for the purpose of speed, not tractor pulls. PEACE OUT

UMMM,can you please stop your drama?I sorry you can't bear to have some else put their opinion out there.I really don't think Dick would like it if we tried to sue him.Maybe you are un-sure of how a bowl blend,larger valves and port work change the flow rates.I think you might want to read my post again before you go jumping to conclusions.Do YOU really think Dart can't design cylinder heads?Keep in mind those are rough guide lines for choosing a cylinder head.OH,Later Gator.

Originally posted by erik erikson
UMMM,can you please stop your drama?I sorry you can't bear to have some else put their opinion out there.I really don't think Dick would like it if we tried to sue him.Maybe you are un-sure of how a bowl blend,larger valves and port work change the flow rates.I think you might want to read my post again before you go jumping to conclusions.Do YOU really think Dart can't design cylinder heads?Keep in mind those are rough guide lines for choosing a cylinder head.OH,Later Gator.

Quit picking on me. I will one day learn to build engines.

Don't quote me and give any opinion you want to. Dart builds excellent heads and has so for a long time. I don't want to bowl blend and resize the valves or port the runners. AS-CAST DART HEADS perform great out the box. I bet Dick would like to hear that. lol

WISH I WAS COOL TOO!!!

Here is what I bought...

Comp Cams XE-285H-10
Rhoads lifters (hopefuly to help with vac on the low end)
Vac canister (to help brake booster)

no name alum heads ( 63cc, 195 runners, large valves)

elect water pump

6AL ignition clone

HEI

etc.

Shorty headers

Nice try Erik. You told 'em 3 times that the heads are too big.

Ray and Fiero, Erik does this stuff for a living. You would be well advised to listen to what he has to say.