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Discussion Starter #1 (Edited)
Hi

I'm rebuilding my bbc. 454 +0.060 over bore. making it a 467.

I have headers, dual 3 inch exhaust, torker edelbrock intake, 750 speed demon vacume carb, merlin cast iron heads (3003). Rear end gear is lower than stock, but I don't know low.

I plan on buy this rotating assembly:

scat 9000 series crankshaft.

scat I - beam 4340 con rods

speed pro forged pistons with a compression of about 10:1 to 11:1.


I'm thinking about one of these cams:

"Competition Cams Magnum Series 280H hydraulic camshaft for Chevrolet BB 396-402-427-454 1965-1996. Great for street rods. Needs headers & 9:1 compression. In 396-402 use 2500 stall converter & lower gears. Has a rough idle.
280/280 advertised duration
230/230 duration @.050"
.520/.520 lift with 1.7 rocker ratio
110 degree lobe separation
RPM power range 2000-6000"

or


"Competition Cams Magnum Series 286H hydraulic camshaft for Chevrolet BB 396-402-427-454 1965-1996. Needs 9.5:1 compression, 2800 stall converter, headers, & lower gears. Has a choppy idle.
286/286 advertised duration
236/236 duration @.050"
.556/.556 lift with 1.7 rocker ratio
110 degree lobe separation
RPM power range 2200-6200"

or

"Competition Cams Magnum Series 292H hydraulic camshaft for Chevrolet BB 396-402-427-454 1965-1996. For street/strip applications. Needs 10:1+ compression, 3000 stall converter or 4-speed, 4.10 or lower gears, and aftermarket intake manifold. Has a very rough idle.
292/292 advertised duration
244/244 duration @.050"
.550/.550 lift with 1.7 rocker ratio
110 degree lobe separation
RPM power range 2500-6500"


What do guys think?

I'm looking for about 500 hp.

The Engine is for a street driven 68 camaro, so I need my vacume brakes.


Sune
 

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Without having ported heads, I would not recommend going with a single pattern cam. Your motor will make more power with a dual pattern cam unless you have heads that flow really well on the exhaust. As far as the power range, I think you are in the right ball park. I would recommend the XE274H (230 236 @.050 .552 .555 lift) for a daily driven vehicle. With that cam and heads, I dont think 500 hp is at all out of the question. As far as compression goes, I would not recommend any more than 10:1 if you are going to want to run pump gas.

Good luck,
Adam
 

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Discussion Starter #3
Hi Adam

Thank you for your response.

I thought that the merlin heads did flow pretty good ??? (it is the rect. port type), I bought them used, they where on a 687 hp engine.

About the gas quality. we have 95 octane readily availably here in Denmark. I was told that that is fine for 11:1 ?

sune
 

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Two things stand out to me-

1. the torker intake

2. the rectangle port heads- with your powerband, you'll never see the potential of rectangle port heads, they along with the torker intake will absolutely kill the low end, something you really dont want on a street car. Id look into buying or trading a for a set of oval ports with a performer rpm intake.

Also, is that rotating assembly balanced?
 

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Discussion Starter #5
Scat says that the crankshaft dosen't need to be balance, it is balanced to oem spec. They say that you can use it right out of the box, this only for the stock stroke not the stroker (+0.250) crankshaft. If it is necessary to balance I will go with the stroker 4.250 crankshaft since it is only $ 20 more.

The torker intake worked very well the engine before. The car would spin the tires if I stomped the gas and really pick up and go.

Also keep in mind it is not a daily driver, It is only for fooling around. But I have never taken it to the track (not to many tracks over here).

But I have to admit I have been thinking about the intake. if it would be better to get the new air cap or as you suggested performer rpm. my problem is that I have nothing to compare with....

What about cam.

I forgot to mention in the first post that I don't care about idle quality as long as it idles under 1000 rpm and I can use my power brakes

sune
 

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With that much head I would look for something in the high 220 range and go with a 1.8 rocker. Lobe sep around 108 or 109. this will give you snappy throttle response and work well with the brakes.

Chris
 

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As far as the head flow goes, those heads do flow good. But for a single pattern cam to be appropriate, I think the heads would have to be ported. As far as compression goes, 11:1 with iron heads might work with 95 octane fuel, I am not sure though. If you know of people who have done that, then I guess it can be done. I would agree that the rectangular port heads are a little much for your combo. To really match them on your motor, you would want a single plane intake (something like a victor) and a fairly large cam and stall; I realize though that that is not what you are after. I guess that If I was in your situation, I would go with the cam that I recommended or maybe the XE284H (2300-6500 .240 [email protected], .574 .578 lift), and a Performer RPM air gap intake. Then run around a 3000 stall. That would match your heads a little better, and the stall would get you in the power range you want to be in for the heads and cam also. You might notice a little squishiness in the brakes, but I think they would still be adequate. If worse comes to worse, and the brakes are bad, I have heard of some people using vacuum canisters. I don't know how effective they are, but it is an idea.

Adam
 

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firestone said:
As far as the head flow goes, those heads do flow good. But for a single pattern cam to be appropriate, I think the heads would have to be ported. As far as compression goes, 11:1 with iron heads might work with 95 octane fuel, I am not sure though. If you know of people who have done that, then I guess it can be done. I would agree that the rectangular port heads are a little much for your combo. To really match them on your motor, you would want a single plane intake (something like a victor) and a fairly large cam and stall; I realize though that that is not what you are after. I guess that If I was in your situation, I would go with the cam that I recommended or maybe the XE284H (2300-6500 .240 [email protected], .574 .578 lift), and a Performer RPM air gap intake. Then run around a 3000 stall. That would match your heads a little better, and the stall would get you in the power range you want to be in for the heads and cam also. You might notice a little squishiness in the brakes, but I think they would still be adequate. If worse comes to worse, and the brakes are bad, I have heard of some people using vacuum canisters. I don't know how effective they are, but it is an idea.

I have to disagree with this cam. Too big. Case in point, I just got done with a customer and a 502CID boat engine. 9 to 1 pump gas, 34 degree timing, single plane intake, 975 CFM carb, a set of untouche Canfield 305cc square ports. Engine made 560#/ft of torque at 4200 rpm and 579HP at 5500 rpm. Camshaft was under 230 at .050" and right at .600 lift. Most over cam and by doing so narrow up the powerband.

Chris

Adam
 

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I understand what you are saying, but my concern is a mis-matched combonation. A set of rectangular port heads on a 468 arent going to start making good power until at least 2000-2500 RPM, and they will want to make power until 6500-7000. On a 502 it is different because of the added cubic inches brings the powerband of the heads down. If you use a 1500-5500 cam with a set of heads that make power from 2500-6500 on your motor, your effective powrband will only be 2500 to 5500 RPM. I think the reason that your 502 made power to the RPM that it did is because of the associated lift. A hydraulic flat tappet cam 225- 230 duration at .050 range will only have around .500 - .530 lift. I would think that if he used the cam that is rated for 2300-6500 RPM, and the intake manifold is rated at 2500-6500 RPM and the heads are going to want to make power from 2500-6500 RPM that that would match better than using a smaller cam. I could be wrong about something, and if I am, tell me. This is just what makes sense to me.

Adam

Something to look at, these are not merlin heads, but they are unported rectangular port heads with a 305cc runner which is about the smallest a rectangular port head comes in, and the suggested RPM range is 2500-6800, I would assume it would be the same for a similarly sized merlin rect head.

http://www.strokerkits.com/305cc_bbc_as_cast.htm
 

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Discussion Starter #10
????

Hmmm now I'm even more confused....

I plan on buying the rotating assembly from these guys:

http://www.fastengineparts.com/

So I would like to buy the cam form them also. to keep the s&h to a minimum (I live in Denmark)

I have been trying to find a dual pattern cam, but they only seem to carry dual pattern cam for marine applications.

If you guys don't mind could you please check out their cam selection and recommend one, that will be good for my use??

Ohh yeah one last thing, I have been trying to find some info on my intake. But I can't find anything. All I'm getting info on the Torker II and not the Torker. As far as I understand it is a single plan manifold.

sune
 

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I would not risk the assembly not being balanced. The imported cranks from China are all over the place. Yes some are okay when spun up with the bobweight, some are not. I'ts not worth the extra $200 not to balance the assembly.

You may want to try www.midwestmotorsportsinc.com They are a WD for most lines and a full shop. Address any e-mails to Brett Meier, owner. They can ship international and prep the parts for you for easy assembly..

Marine Cams/Drag Cams/Circle Track cams, doesn't matter. A cam is designed to make power in a specific rpm range. Cam doesn't know whether its going in a boat or a drag car. Labels like these are for marketing.

Adam is correct, you have a large set of heads for combo. For the CID you have, a camshaft with short duration and moderat lift will get the charge into the head and shut the valve quick. This packs the cylinder at low rpm and gives you good cylinder pressure. This will build a broad power band. Street engines need to make stop light to stop light power. . .torque.

Chris
 

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I understand what Ctsraub is saying about the cam. Regardless of what route you take, I will be interested in how it runs.

Good luck,
Adam
 

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Discussion Starter #13
Hi Chris

If I need to have the whole assembly balanced, I might as well go with the stroker combo (4.250 stroke) Right??

Also I checked out that site that recommended, but they don't seem to have any big block parts.. ??

I never thought about cams the way you described it, but it all seem to be making sense. But what do you consider "short duration" and "moderate lift" ??

Again thank for taking time to answer all my stupid questions, it is really appreciated!

sune
 

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Sune,
No such thing as stupid questions.

The owner, Brett, has been in the industry for several years. He just bought Midwest about a year ago. They do mostly circle track stuff but his background is drag engines. He is doing a set of 632CID boat engines right now.

For street and marine their is no replacement for displacement. Just rememember with a stroker you are going to have some grinding and will need a notched oil pan (I am in no way trying to sell you one of our pans just stating the facts). 8.1 Liters over on your side of the pond would be impressive. Better match for your heads. Could push a legit 600HP with 11 to 1 compression if you wanted.

Camshaft would change, but as for the 468 CID, duration in the high 220's and around .600" lift. I like 1.8 ration rockers on bbc. Gets the valve open quick. Helps with throttle response.

I would e-mail Brett and ask him for a package deal.

Chris
 

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camshaft/intake

i used an xe cam from comp. call comp. with details of your motor for proper cam selection. also, i used the edelbrock airgap duel plane intake. this combo gave me plenty of power and vacuum. also, plenty of rumpty-rump. this combo worked fine on my street driven 468 bb.
 
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