Small Block & Big Block Chevy Specific Mouse & Rat Motor Discussion & Conversions

for you big block guys?

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Old 01-08-2005, 12:59 PM
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How much power will a destroked 454 to 427 with peanuts heads, eldebrock intake and a hydraulic roller cam in the 236-248 duration make? this is totally a street set-up?
Old 01-08-2005, 01:11 PM
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i will rev like crazy i say maybe 500-600 range
Old 01-08-2005, 01:19 PM
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Originally Posted by eric69nova
i will rev like crazy i say maybe 500-600 range
What kind of quarter times do you think this set-up will run in a full weight 69 camaro 3.90 gears and a 700r4?
Old 01-08-2005, 02:43 PM
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if u get it to hook i would say probably a low 11

also depends what type of tires and stall u have man
Old 01-08-2005, 08:13 PM
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Um...dude, peanut heads are worthless in a hotrod. Port velocity is high, but can't flow enough for higher rpm. 500hp maybe if you use a blower/turbo/nitrous. Why destroke it? It will make less torque. If you want a higher peak hp rpm, use a bigger cam.
The peanut heads are good for trucks, but 5k rpm would be the cutoff.
Build it 454 with large oval port heads and you'll see a LOT better results.
Good oval port, the cam you mentioned,9:1 compression,2.19 intake and 1.90 exhaust valves, 850 cfm carb, dual plane, and headers should make about 450 hp if it's set up right. Major bowl work is necessary on the heads, too.
Old 01-08-2005, 08:24 PM
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427s are great motors if they're built right. You're not going to lose a lot of torque going from a 454 to 427, but with oval port heads, you're not going to make much power over 5,000 RPM, where the advantage of the short-stroked 427 would be seen.
Old 01-08-2005, 08:35 PM
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Originally Posted by That_Is_My_El_Camino
427s are great motors if they're built right. You're not going to lose a lot of torque going from a 454 to 427, but with oval port heads, you're not going to make much power over 5,000 RPM, where the advantage of the short-stroked 427 would be seen.
You're right, you won't lose a lot of torque, there will be a noticeable difference on the bottom end. And peanut heads are the ones that suck, as the large oval port heads can flow for a 454 to well over 6k without regular porting. Ever heard of Lingenfelter? He built some downright scary 496's with oval port heads in the early 90's(I think that's when it was). It's the bowl work and large valves that turn them on . The shorter stroke of a 427 would only be an advantage at VERY high rpm's, and that's not gonna happen on a street motor.
BTW-Why the small cam?
Old 01-08-2005, 10:02 PM
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This is not my combination, it is my brother's. He does have the stock oval ported heads, sorry I thought peanut heads were oval Anyway he is getting an eldebrock performer rpm intake with a 248 duration cam with I think a 610 lift. I been trying to convince him to get some better heads ( AFR-eldebrock, brodix, but he swares up and down that these oval port heads will be excellent for his combination.
Old 01-08-2005, 10:21 PM
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Peanut heads are small oval, truck heads. Large ovals are found on passenger cars, maybe marine applications, etc. There is a BIG difference between the two.
Rectangle ports are overkill for a street bbc under 540 MOST (not all) of the time.
Old 01-12-2005, 04:02 PM
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heads make or break a motor.please leave it a 454 ci and order some aluminum ones.lots of $$$$$ but well worth it.
Old 01-12-2005, 05:02 PM
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Originally Posted by slow trap
heads make or break a motor.please leave it a 454 ci and order some aluminum ones.lots of $$$$$ but well worth it.
Aluminum heads don't make any more power than iron, and under the same conditions actually make less. The heat dissipation of aluminum allows for higher compression ratios because the engine will have lower combustion chamber temps., but the lower temp. doesn't make as much power. Most people think that aluminum heads allow higher compression but the reality is that you have to run higher compression to make the same power(about 1 point higher). The weight advantage is also minimal and wouldn't even be noticed by most people on a street car. It is true that they cost a lot of $$$ though...
Old 01-13-2005, 11:46 AM
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i just said aluminum because you'll shave alot of weight off the nose.i'm sure if you run say 10.5 cr alum v/s 9.5 iron you will make more power even though iron retains combustion heat better.
Old 01-14-2005, 08:00 AM
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The factory Oval ports work great for a street/strip car. I ran 10's NA with a set on my 454 Chevelle. I ran 10's with Aluminum Sq Ports as well. Difference..much more gear and converter necessary for the sq ports. Also revved over 7500rpm. I'll take the Oval ports anyday. good torque and decent flow.
$.02
Walt
http://www.personal.kent.edu/~wbainey/CHEVELLE.htm
Old 01-14-2005, 07:36 PM
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Originally Posted by BlownShovel
The factory Oval ports work great for a street/strip car. I ran 10's NA with a set on my 454 Chevelle. I ran 10's with Aluminum Sq Ports as well. Difference..much more gear and converter necessary for the sq ports. Also revved over 7500rpm. I'll take the Oval ports anyday. good torque and decent flow.
$.02
Walt
http://www.personal.kent.edu/~wbainey/CHEVELLE.htm
What kind of cam you had?
Old 01-14-2005, 08:02 PM
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I totally agree about the peanut port heads being junk. That was like the worst head GM ever made for the BBC. I have a set on my 84 Chevy K30 truck and its a dog past 2k.

Regular oval ports like the 049's and 781's are a good oval head to use. I have some leads on 781's
Old 01-14-2005, 08:58 PM
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Originally Posted by texada
What kind of cam you had?
The best cam I had with the Oval ports was a Solid roller..Ultradyne 269/275 .700" lift.
I had this and some other cams in the Sq portcombo. 270/278 .725" Sonny Cam 274/278 .710".

I also used some street roller grinds with the OVal port combo Anything from Crane 234/244, Comp 246/246, Comp 264/264

Walt
Old 01-16-2005, 07:56 AM
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I agree with what PWR2W8 was saying, a destroked motor you're gunna have to spin really hard to make it go into its power band,it will have tons of power up top but not a lot down low..Go with a stroker 454 or something and now your gunna make some power and get some good cubes to go with it..And if you have a BBC High perf head I would just put Iron heads on it they make good power for what they are..Or buy some Edelbrocks or something..
Old 01-21-2005, 10:20 AM
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I dynoed mine
My motor is a 454 truck motor out of a 85-88.
I know it has a "mild" cam according to the guy I bought it from but he has no clue what cam it is.
I think it's an RV cam because.......
My set up is a 454 4-speed tranny
Edelbrock Air-Gap intake and power-shot breather
Holley 750 double pumper
Holley fuel pump
Hooker headers
MSD ready to run distributor and all the other MSD goodies (coil, wires, 6AL)
Flowmaster exhaust

It's tuned just OK, meaning it's not running rich or lean, just about right but it's very difficult to start in the cold with no choke. Since I have no clue about what cam is in it, it's really a guessing game getting the timing perfect.

Anyway, with that set-up, it dynoed 288rwhp, 450rwtq. Peak power at 4500rpm
Needless to say, I was disapointed but it will get better.
Mine has the "peanut port" heads and I KNOW those have to go.
I have never had it at the track so I can't say how fast it is, but it's a tire skorching torque monster
Old 01-21-2005, 11:55 AM
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another vote stating peanut ports are NOT the head of choice.

Factory oval port heads are nice, but they fall into the same catagory as most of GM production heads (meaning what was available stock) when compared to today's aftermarket heads. Go with an aftermarket head if possible.

A good friend of mine with a speed shop here in Gainesville had a nice set of 60's vintage ported oval ports on a 454 and they did quite well, but a set of out-of-the-box edelbrock performer rpms made a 3 tenth difference, and figure 1 tenth of that was weight. The compression ratio came down somewhat (about 1/2 a point), but he no longer had to mix race gas and pump gas.

I also agree square ports are usually overkill for most street/strip motors (like pwr2w8 I said most, not all).

Derek



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