66Chevelle350
Member
Posts: 78
Loc: Falmouth, Mi. , USA
Reg: 02-12-02
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05-27-12 08:19 AM - Post#2230286
I have the folowing engine and am thinking about a Thumper Cam and Head change. Would this see any major change? Maybe an intake change also. The heads I have now are ported.
350 Engine
ZZ-2
Bored .30 over
Align Honed
Deck Squared
Rotating Assembly Balanced
ARP Main and Rod Bolts
General Motors 5.7” Pink Rods
TRW Forged Pistons Flat Top 10.40 Compression Ratio
Hastings Molly Rings
Crane Camshaft 509/528 Lift @ 1.5 Ratio with 222/230 Duration
Delco Roller Lifters
Molly Push Rods
Comp Cams 7/16 Studs and Roller Rockers
GM Part # 10088113 (Complete Head # 10185087, Bare Head # 10125374) (L98) Aluminum Heads Ported for Street
GM Part # 10185024 High Rise Intake Manifold
Richmond T-10 4-speed Transmission
3.73 Posi-traction
66 Chevelle
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C10 Sleeper
Valued Contributor
Posts: 3426
Loc: Redding Ca
Reg: 03-17-09
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05-27-12 02:21 PM - Post#2230408
In response to 66Chevelle350
I think you would be better off staying away from the thumper cam.
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66Chevelle350
Member
Posts: 78
Loc: Falmouth, Mi. , USA
Reg: 02-12-02
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05-27-12 04:56 PM - Post#2230479
In response to C10 Sleeper
One of the things I would like to know is if anyone has changed heads, and gained power?
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 davidchristopher
"4th Year" Gold Supporting Member
Posts: 1664
Age: 42
Loc: Saint George, Ontario, Ca...
Reg: 08-02-09
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05-27-12 05:08 PM - Post#2230485
In response to 66Chevelle350
I thought L98 heads were... like 58cc or something? What's your compression ratio?
1951 Chevrolet Styleline Special. (350 4 Muncie '55 Driveshaft CE crossmember Heidts Mustang II front suspension, 3:10 Posi)
The '51 Chevy Blog
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 navygunner08
"2nd Year" Silver Supporting Member
Posts: 644
Loc: New London, CT
Reg: 02-13-11
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05-27-12 07:23 PM - Post#2230543
In response to davidchristopher
I would be willing to bet that if you stuck with your current cam and changed to better heads you would see a hue improvement. Those heads are restricting your cam from reaching its full potential.
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C10 Sleeper
Valued Contributor
Posts: 3426
Loc: Redding Ca
Reg: 03-17-09
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05-27-12 07:58 PM - Post#2230560
In response to navygunner08
I agree with navygunner.
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66Chevelle350
Member
Posts: 78
Loc: Falmouth, Mi. , USA
Reg: 02-12-02
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05-28-12 05:31 AM - Post#2230647
In response to C10 Sleeper
They are 58 cc heads, my compression I was told by my engine builder was 10.5.
I was thinking about Dart Heads.
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66Chevelle350
Member
Posts: 78
Loc: Falmouth, Mi. , USA
Reg: 02-12-02
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05-28-12 05:32 AM - Post#2230650
In response to 66Chevelle350
Would a new intake make any difference?
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C10 Sleeper
Valued Contributor
Posts: 3426
Loc: Redding Ca
Reg: 03-17-09
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05-28-12 07:30 AM - Post#2230697
In response to 66Chevelle350
You have to look at the whole picture and pick a combination of parts that are going to work together. Throwing random parts at it is likely to do more harm than good.
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navygunner08
"2nd Year" Silver Supporting Member
Posts: 644
Loc: New London, CT
Reg: 02-13-11
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05-28-12 07:43 AM - Post#2230704
In response to 66Chevelle350
You should be able to keep the intake. You may want to port match the intake to the new heads if you get them. A dual plane intake, like the one you have, is better for lower RPM (below 6000RPM) performance. The Intake, Heads, Cam, Torque Converter and Rear End Ratio all need to be matched to get the best performance out of your combination. Your intake and cam are fine. I would get a set of good heads in the 180cc to 195cc intake runner size range. Since you are running a manual transmission you dont have to worry about matching the converter, but your gear ratio's are important to think about as well. Your rear end gearing is right in line as well so you shouldnt have to do anything with that. Dart makes good head and they recently came out with their SHP aluminum heads that are very well priced for the value. You can find a great deal on RHS ProAction Heads at competitionproducts.com. Those are even better heads at around the same price.
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 gchemist
Senior Chevytalk Moderator
Posts: 20885
Loc: Austin, TX 78748
Reg: 05-09-00
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05-28-12 08:06 AM - Post#2230712
In response to navygunner08
"The ZZZ and ZZ2 motors were 350ci, 345hp @ 5,250 rpm and almost 400# XXXXX torque, four bolt mains, 9.8:1 cr, Corvette aluminum "D port" heads, 1.94/1.50 valves, angled spark plugs, five quart Z28 oil pan, "pink" rods, a single profile roller lifter hydralic camshaft with .480" lift/.235" (@ 1.5 rocker ratio) duration which gave it a nice rumbling idle characteristic, but more for mid range and top end rpm performance. The later ZZ3 and ZZ4 motors have split profile cames which gave better low end and mid range rpm performance. The later ZZ3 motor was still rated at 345hp, but the ZZ4 got upgraded to 355hp.
The ZZZ and ZZ2 had forged steel cranks, manual fuel pump pads, side and front motor mount pads, one piece rear main seals, a GMPP aluminum high rise manifold and an "improved" HEI ignition (@10 degrees BTDC). They also had steel timing chain covers rather than the later version composite w/ O-ring timing chain covers. All ZZ series motors came with 8" harmonic balancers. The dip stick was on the passenger side of the motor. They came with long water pumps which most people promptly changed to a short pump. The ZZ series motors all require 91 or better octane fuel.
The one major caveat about the ZZZ and ZZ2 motors was the offset wrist pins in the pistons. Until the motors came up to operating temperature, they had a distinctive clattering in the top end. Some people thought there was something wrong with the engine for that reason. The later ZZ series motors got an improved piston
From: http://www.justanswer.com/chevy/1e3cf-trying-co nfi...
'83 Silverardo XST - ZZ4 powered
'96 GMC Jimmy LS |
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66Chevelle350
Member
Posts: 78
Loc: Falmouth, Mi. , USA
Reg: 02-12-02
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05-28-12 01:40 PM - Post#2230812
In response to navygunner08
I have not heard of the RHS ProAction Heads
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busterrm
Contributor
Posts: 999
Loc: Wichita Falls, Tx
Reg: 08-31-10
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05-28-12 06:58 PM - Post#2230923
In response to navygunner08
You should be able to keep the intake. You may want to port match the intake to the new heads if you get them. A dual plane intake, like the one you have, is better for lower RPM (below 6000RPM) performance. The Intake, Heads, Cam, Torque Converter and Rear End Ratio all need to be matched to get the best performance out of your combination. Your intake and cam are fine. I would get a set of good heads in the 180cc to 195cc intake runner size range. Since you are running a manual transmission you dont have to worry about matching the converter, but your gear ratio's are important to think about as well. Your rear end gearing is right in line as well so you shouldnt have to do anything with that. Dart makes good head and they recently came out with their SHP aluminum heads that are very well priced for the value. You can find a great deal on RHS ProAction Heads at competitionproducts.com. Those are even better heads at around the same price.
I agree RHS makes a very good head, I used a set of RHS 200cc heads on a 385 and they worked very well. A set RHS pro action 180cc are like 880 bux at competition products, which is a good price for those heads.
==== BOB ====
If I can't smoke the tires I want more!
1976 Chevy Nova
2007 Chevy 1500 1/2 ton
2005 Yamaha Vstar 1100 midnight custom |
Edited by busterrm on 05-28-12 07:05 PM. Reason for edit: No reason given.
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66Chevelle350
Member
Posts: 78
Loc: Falmouth, Mi. , USA
Reg: 02-12-02
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05-29-12 07:24 AM - Post#2231056
In response to busterrm
I have found 180cc & 200cc heads several places, but now the question is what brand? Also what cc heads? 180cc or 200cc and which 64cc or 72cc.
When the time comes for a new lower end I will be going with a 383 so I want something that can be used then also.
Thanks
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C10 Sleeper
Valued Contributor
Posts: 3426
Loc: Redding Ca
Reg: 03-17-09
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05-29-12 09:12 AM - Post#2231090
In response to 66Chevelle350
My advice is figure out some realistic goals for your intended use and budget. Then do some research on what it will take to reach those goals. There is a website and I can't think of the name off the top of my head but it has several sbc combos posted. Between the parts list and power numbers it might give you a starting point of what to shoot for.
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 rumrumm
"12th Year" Silver Supporting Member
Posts: 1790
Loc: Macomb, IL
Reg: 10-18-01
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05-29-12 11:30 AM - Post#2231160
In response to C10 Sleeper
IMO, I would hold off until you build your 383--why pay to do things twice? Now if you plan on selling your 355 and purchasing or building a 383, then that is one thing, but if you are planning on turning your 355 into a 383, hold off. You will want to change a lot.
Your present cam is a good choice for a 355, and if you upgrade to a better flowing set of heads, choose a head in the 180-190 cfm range with a combustion chamber around 64cc's. 200 is too big--better for a 383 than a 355. Depending on how much you want to spend, AFR, Profiler, Brodix, and RHS aluminum heads are very good choices.
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66Chevelle350
Member
Posts: 78
Loc: Falmouth, Mi. , USA
Reg: 02-12-02
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05-29-12 05:56 PM - Post#2231285
In response to rumrumm
Thanks, and if the same head would not work for both engines I will just wait.
Thanks Again
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busterrm
Contributor
Posts: 999
Loc: Wichita Falls, Tx
Reg: 08-31-10
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05-29-12 08:30 PM - Post#2231336
In response to 66Chevelle350
Thanks, and if the same head would not work for both engines I will just wait.
Thanks Again
I agree with Lynn, why waste time on 355 when you could put the bottom end in it now and have a 383. With that number of cubes I'd go with at least 200cc heads.
==== BOB ====
If I can't smoke the tires I want more!
1976 Chevy Nova
2007 Chevy 1500 1/2 ton
2005 Yamaha Vstar 1100 midnight custom |
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