waid1017

For my 77, I was planning to purchase the GMPP Vortec Heads with GMPP 350HO cam for a 330hp build. I saved up little more and now I am thinking about the aluminum head top end kit.

I am really considering the Edelbrock E-Tec Top End Kit #2099. This is the 435 hp & 435 ft/lbs. w/ retro-fit hydraulic roller cam.

http://www.edelbrock.com/automotive_...ek_chevy.shtml

What is interesting about this kit is that the performance results are obtained on a 350 c.i.d. shortblock w/ 9.5:1 compression.

Additionally, Edelbrock sells a complete crate engine with this top end built with a new "ZZ" 4-Bolt 1-Piece Rear Main Seal block with compression of 9.5:1.

http://www.edelbrock.com/automotive_...etec_435.shtml

My 77 motor has 8.5:1 (maybe 8.2:1) compression with 76cc heads. With 64cc heads I will be around 9.5:1 (or 9.2:1). The thing I am not too crazy about is the cast crank and two piece mains.

I want to pull my motor out only once and I have a feeling I am going to regret it if I don’t get Edelsbrock’s top end kit for more power.

I need some thoughts and opinions on this kit (pluses and minuses). My car is not a daily driver but just a weekend fun car.

Thanks

Waid

OzzyTom

A complete kit like that provided by Edelbrock takes a lot of the guess work out of matching the components.

My motor is based on the Edelbrock 383 signature series specs.
Edelbrock rate it at 460HP/460 lbft with 9.5:1 cr.
I have a touch more compression at 10.3:1, and recent dyno results put down 373 hp and 396 lbft at the rear wheels. I''m happy with that.

There may be other kits available, but the Edelbrock components in my motor certainly work well together. I'm sure the kit you're looking at for your 350 would also meet specs.
Bear in mind the need for lower diff gears and stall converter (if auto) to maximise driveability and performance.

waid1017

With my setup Edelbrock (most likely) or Vortec, I am planning on 2500 stall converter & 3.73 gears. I really want the 4.10 but with a TH350, the engine would be running high rpm at highway speeds.

Waid

waid1017

Here is the power graph

fitter

Your compression ratio will be higher with smaller cc heads. I have Edelbrock performer rpm heads and a performer rpm air gap manifold on my 383. I do like Edelbrock however: I think their numbers on HP and torque are on the exaggerated side. Good luck with your build.

63mako

Your plan is ok if your bottom end is really solid and rpm is limited. I would not expect 435 HP out of that combo with 170 CC heads. Seems optimistic to me. The problem is bumping the HP to over 400 hp on a 35-40 year old cast bottom end with components that have 6500 RPM capabilities. You are doubling the forces that stock bottom end was originally designed for and increasing the potential redline 700 RPM. The weak link always breaks. I have seen many seemingly good factory bottom ends fail once the top end is rebuilt for more power. Check compression, leakdown and make sure you have good idle oil pressure at a minimum before going this route. Low mileage is a plus too.

waid1017

The botton end is my biggest worry. My car/motor has 37,000 miles on it and the botton end looks fine - what I am able to see. This is the hardest part about deciding if I should go for a mild vortec build or go all out with the Edelbrock top end.


Carcraft made 348hp with stock vortec GMPP 350 HO with Hedman headers, Borla 2 1/2-inch stainless steel Pro X/S mufflers and QuickFuel 650-cfm carb.

http://www.carcraft.com/techarticles...h/viewall.html

With Comp XE268 cam, Carcraft managed 377 hp and an amazing 415 lb-ft of torque on the 350.

http://www.carcraft.com/projectbuild...l/viewall.html


Thanks

jackson

seems your 77 has L48 base motor? If so, it has low compression Dished pistons.

also seems that EB kit's ?hp numbers were found with higher comp flattop pistons.

a good used pair of either ZZ4 aka L98 (~58cc) GM aluminum heads or GM iron Vortecs (~64cc) ... along w/ a new, but typical HFT cam&lifter kit will easily get you to 325fwhp and, even more.

but don't buy used stuff unless you Know how to separate the wheat from the chaff; and Know how to balance potential machinework against new costs.

jackson

also
me thinks EB kit 2099 has too much cam (2201) for a lower comp motor.

instead of 2099, me thinks EB kit 2088 has a better cam (2208) for a 9:1 motor ... and 9:1 is about where a Dish-piston L48 ends up when using 64cc chambers.

63mako

with jackson. Yes, ZZ4 uses a flat top piston and 58CC heads and is 10 to 1. Substitute 64 cc heads and you drop to 9.5 with a thinner gasket. Subtitute dish pistons and you are at 9 to 1 maybe a little more with a 1094 gasket. Cam don't match. Trickflow does make a 56 CC 175 intake port head that flows way better than the gm 113 heads. They will get you to about the correct compression for that cam but you still have a RPM limited factory cast bottom end and the cam specs in the 2088 kit are really crappy for a 9 to 1 roller setup. The difference between advertised duration and duration @ .050 are wider than most flat tappet cams???
I would look at the trickflow 175 intake port 56 CC chamber heads with a 1094 head gasket, a better roller cam
http://www.summitracing.com/parts/HRS-CL110245-10/
and a matching Performer RPM intake. With your 3.73 gears and 2500 stall it will be a good combo with a cam in the operating range to use the converter and gears but not pull past your bottom ends capabilities.

bluedawg

I'd go afr 180's & there website has a few dyno proven combos that make 420 or so horse all in by 6 grand that you could copy off of. Like others have said the crank shaft and pistons are the weak points so the use of forged components helps to insure that you'll get longevity. If you have the deck height set @ .002'' and use a .039'' that would keep your quench in good working range. If you don't want a two piece main seal, put your original engine on a stand and moth ball it, get your self a good 1 piece rear main seal 4 bolt main block and start with that. if you wanted you could always stud or splay the mains on your original block, but it is 34 years old, and probably more valuable as an original motor. Good luck with your porject & staying within your budget.

waid1017

The compression on my 77 motor with 76cc heads is 8.5:1 with dished pistons and it might actually be as low as 8.2:1 with stock 0.039" head gasket. If I get 64cc heads, the compression will go up by a full point to 9.2-9.5:1. It might even go higher with Fel-Pro 0.015" shim head gasket. Most llikely I will get the 0.029" - GM Performance Composition Head Gaskets #10105117. With 64cc heads & 0.028" head gasket, I will have minimum compression of 9.5:1.

Agree?

The other alternative is to stick with Vortec heads and use Howard Roller Cam / Roller Lifter combo with my Q-jet and I can still keep it under $2000. Howard Cam has the lowest price on cam / retro-roller combo. My target is 400hp.

Heads - GMPP Vortec 12558060 $600.00

Cam/Lifters - Howards Cams CL110245 $500.00
--Duration @ 050: 234-238 Lift: 0.539-0.548
-
Intake - Edelbrock Performer Vortec 2116 $180.00
Carburetor: Stock Q-Jet - -
COMP Cams 1.5:1 Aluminum Roller Rocker Arms 1015-8 $175.00
GM Performance LS6 Springs 12499224 $68.00
Comp Cam Magnum Pushrods 7.8" CCA-7372-16 $100.00
ARP Head bolts ARP 134-3601 $77.00
ARP Intake bolts ARP 134-2002 $18.00
Cloyes Gear Timing Cover 9-221 $116.00

$1,834.00

63mako

I think that is the factory roller cam cam. You want the retrofit roller. with the same part #. 5.25 lift.
http://www.summitracing.com/parts/HRS-CL110245-10/ or
http://www.summitracing.com/parts/HRS-CL110245-12/
I ran your numbers through a compression calculator. With a l48 12cc dish piston, 64 cc head. .028 gasket, 4.165 gasket bore, .025 deck height, 3.48 stroke your at 9.2 to 1. The 56 CC head puts you @ 10 to 1. Using the 1094 gasket with the 64 CC head puts you at 9.5 to1. The cam will work well with either the 9.5 iron head combo or the 10 to 1 aluminum head combo. Both will work with your 2500 stall and 3.73 gearing. I see 400 HP with either setup with a performer RPM intake not the performer but probably more with the 56 CC trickflow aluminum heads. They will come assembled with the springs. If you figure vortec heads they are limited to 4.50 lift. The beehive spings bump that to about .550 but figure spring cost, locators, retainers and locks plus they need to be setup to 1.800 installed height. Either is a better setup than the eldebrock top end kit.

waid1017

The difference between the CL110245-10 & CL110245-12 is the Lobe Separation (degrees) 110 vs. 112.

Which is better for my application. The car is not a daily driver and I want more muscle car sound.

CL110245-10
Duration at 050 inch Lift 225 int./231 exh.
Valve Lift with Factory Rocker Arm Ratio 0.525 int./0.525 exh.
Lobe Separation (degrees) 110
Fair idle, street/strip. Automatic OK with 2,500+ stall.

CL110245-12
Duration at 050 inch Lift 225 int./231 exh.
Valve Lift with Factory Rocker Arm Ratio 0.525 int./0.525 exh.
Lobe Separation (degrees) 112
Fair idle, street and mild performance usage. Crisp throttle

63mako

If you want more lope go with the 110 LSA. You will want to buy a $20 pushrod length checker and measure for your pushrod length. They will be around 7.2 -7.3 length depending on valve length , head used , lift, cam base circle, lifter length. Don't buy pushrods until all is assembled and you check for length.