|03-01-2013 11:12 PM|
use a 750 cfm carb
and roller that is better,not the same
110885-10 NA 278 278 225 225 .525 .525 110 106 Hyd. Hyd. 1,2
2000-5800 Fair idle, Street high performance. 2200+ stall, aftermarket intake, headers.
|03-01-2013 10:59 PM|
So I bought the packaged sale. The heads are Edelbrock Performer Rpm 70cc straight plug, square exhaust port. There is no model # stamped anywhere just a casting code 6061. Guess thats how Edelbrock did it back in 1994. Might be useful info for someone down the road. Does anyone recognize this brand of roller rocker?
This site has been really useful learned alot. I pretty much have my engine planned out. 2 things left though Roller cam or flat tappet and which rotating assembly?
From what I have been reading a Scat cast crank and hypereutectic dished pistons to keep compression down sounds good. The build so far:
Edlebrock rpm performer heads 70cc Combustion Chambers, 170cc Intake Ports
-Xtreme Energy XE268H, Hydraulic Flat Tappet Camshaft Lift: .477''/.480'' Duration: 268°/280° or roller cam not sure yet.
-Edelbrock 1806, 650 CFM Carb
-1 5/8 hedman long tube headers
-1980 l82 corvette 4 bolt main block
Thinking about switching to roller cam after reading about wiped cam lobes and break in procedure. Anyone know what the XE268H equivalent of a roller cam would be?
|02-27-2013 04:14 PM|
"Can a 9.5 compression ratio still run 87 octane?"
I know its possible. Todays FI cars do it. Every engine is different. Lots of variables. From what I've read a tight squish(distance between flat portion of piston and flat part of head)(.035"-.045") is one of the most important factors in reducing the chance of detonation by increasing the turbulence in the chamber, but then thats just what Ive read and have no 1st hand proof.
One of the most influential is inlet air temp. Cold air induction is a big plus. I know that from experiance.
Rear gearing is another major factor. The higher the engine load the more likely it will detonate. A tall gear like a 3.08:1 is more engine load than a low 4.11:1. Sharp edges in the combustion chamber/piston crown will get hot enough to cause pre-ignition and/or detonation. The lower the rpm the more time unburned mixture is expossed to more heat/pressure/load that can induce detonation. Oil getting past the guides/rings and into the chamber can cause detonation. A lean AF ratio is another.
I think that if you polish the chambers/piston crowns/valve edges(exhaust anyway), use a quality ignition system, correct air/fuel ratio and no oil, cool air, and a tight squish that you can use 87 octane with aluminum heads at 9.5:1CR, but thats just my opinion. Your location and ambeint air temps/fuel quality as well as what I mentioned and other factors I haven't all play a part.
I usually run 91 octane on my carbed iron head 350 with about 9:1CR and sometimes have detonation after heat soaking on a hot day.
Maybe someone else can chime in?
|02-26-2013 10:42 PM|
|02-26-2013 10:11 PM|
|vinniekq2||A 350 roller cam engine will make more power than a 383 flat tappet motor if funds are an issue.400 hp if the heads flow enough and 87/89 friendly|
|02-26-2013 09:36 PM|
|Chad.||Yes the casting # is 6061. I called Edelbrock the best he could tell me is they are either 64cc or 70cc Performer RPM heads. Wondering why they just didnt put model #s on them. Didnt mention anything about runner size but for what I want it to do I think 170cc Intake runner would be just fine. As for the fluidampr I will just sell it. Thanks ssmonty I narrowed it down to a low compression 383 stroker at least, and that combo looks pretty good for what I want the engine to be. Can a 9.5 compression ratio still run 87 octane? I read somewhere it has to be 9.1 or less. Yea I know I am cheap lol|
|02-26-2013 07:38 PM|
roller cam and 9.2:cr will make 400 plus horse power if you use dart shp or better heads. I would run that on 87/89.I would not expect that power from a flat tappet hydraulic.
Maybe someone else would do it or try,,,?
|02-26-2013 07:18 PM|
Somthing to consider. Hope it helps.
|02-26-2013 06:37 PM|
Just my two cents.
I haven't used a Fluidampner, but have heard a lot of people say they wouldn" use one if it was given to them. Doesn't get the job done.
I had a set of the Edelbrock valve covers, and the oil baffle for the pvc valve/breather is a joke. Gave them away along with the plastic socket head capscrew plugs they came with to make them look like a two piece cover.
I can say from experience that I wouldn't waste the energy to throw the ACCEL distributor in the dumpster. Google it.
You can use a roller cam if you buy "retrofit" roller lifters, but they're not cheap, but may be less than a ruined engine from a wiped-out lobe on a flat tappet cam which is happening all the time now. Google it.
400 HP from a 350 on 87 octane? Aint saying it can't be done. Good luck.
To make higher horse power usually means raising the rmp where the torque is made. Raising the rpm usually means a cam with long duration. That usually means raising the compression to make it run efficiently, which usually means higher octane to keep it from self destructing from detonation.
Easier to make more torque with more cubes. If you are going to buy a new crank, might as well make it a stroker for a bit more money. Check out the cost of a 350 Scat crank(3.48" stroke) vrs. a 383 Scat crank(3.75" stroke) at Summit. With a 12cc dish piston, 5.7 rods, 4.166 bore gasket .039" thick, and a zero deck, the 70cc heads would make for about 9.6:1 static comp. ratio. and a DCR of 8.0:1 with the XE268 cam. 412HP using Cam Quest software.
|02-26-2013 04:25 PM|
[QUOTE=Chad.;1650620]Yea that sounds close, lower compression 400 hp or so 383. I plan on using my 1980 L82 4 bolt main block with a Hydraulic Flat Tappet Camshaft though not a roller too pricey and would it even work with my block? I dont know[/QUOTE
I was introduced to my first roller cam in the 70s
since then I see no reason to use a flat tappet cam
|02-26-2013 04:11 PM|
Sorry about that. I was going by Edelbrock's website that shows 60619 as a bare single head.
Edelbrock.com - Cylinder Heads - Chevy - Small Block - Performer RPM Small-Block Chevy
I should have known better because my pn 6073 heads have 6061 cast into them also. As I said earlier they are straight plugs heads, but 70cc.
I believe you'll find the actual part number on the end of the head where the accessory mounting holes are located. If they are that old they probably have the flat tappet cam springs installed.
Some here have said that you shouldn't try to do any porting on them, and that they are optimised from the factory.
I don't agree, and believe they can be improved with a little time and effort.
Again sorry about saying they were angle plugged. Just trying to help.
|02-26-2013 12:38 AM|
|vinniekq2||By the time you by all the additive for your oil changes,it might be cheaper to get a roller cam|
|02-25-2013 10:38 PM|
|Chad.||Yea that sounds close, lower compression 400 hp or so 383. I plan on using my 1980 L82 4 bolt main block with a Hydraulic Flat Tappet Camshaft though not a roller too pricey and would it even work with my block? I dont know|
|02-25-2013 10:31 PM|
|vinniekq2||so a 9:1 383 with small hydraulic roller,380 plus HP?|
|02-25-2013 10:17 PM|
|Chad.||I dont mind reselling actually its fun for me. Nothing too crazy not planning on racing or anything like that. I just want a nice cruiser that I can take to work sometimes and drive on weekends but still make decent power. Also the lower octane I can run the better 383 stroker or 355 What I dont want is an obnoxious beast that will launch me from every red light like I am heading down the quarter mile.and a tame stall/stock converter|
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