Lunati cam and Pro Comp head discussion

[nlauffer]

I know I have posted an engine question before and I have read some cam and head discussions, but here it is again. 

I have my 1972 2 bolt main 350 block on the engine stand.  It has been bored .040, and crankshaft turned 10/10.  It has stock rods with new stock rod bolts and stock style dished hypertectic pistons.  Unfortunately, the motor sat unassembled for 10-15 years.

The block just needs cleaned and I'm thinking about zero decking it.  I don't know if it will be worth it, though.

The crank was stored with a coating used to seal up alcohol injection system.  After that long of being stored it appears to have penetrated the coating.  My question is, turning a stock GM crank to 20/20 costs about $75, but a new Scat costs $199.  Is it considerably beneficial to purchase a new crank or save a few bucks and refresh mine?

The pistons and rods have been soaking in WD40 because they are somewhat seized up.  I have been able to released them all.  I was thinking about replacing the bolts with ARP wavelocks.  Also, I thought about flat top pistons.

Now for an explaination of what I am building.  This will be a street driven daily driver.  Not much highway time and probably never on a track.  The truck already has 3.73s I believe.  If it has 3.42 I'll be happy, but if lower than that they will get changed to 3.73.  The Th350 will stay for awhile.  Maybe in the future a 700R4 will go back in.  Not until I get some more money though.

The top end I have narrowed it down to is a set of straight plug 190cc runner Pro Comp aluminum heads with 64cc chamber.  The cam I want is the Lunati 10120702: 
                                                        •Advertised Duration (Int/Exh): 262/268
                                                        •Duration @ .050 (Int/Exh): 219/227
                                                        •Gross Valve Lift (Int/Exh): .468/.489
                                                        •LSA/ICL: 112/108
                                                        •RPM Range: 1400-5800

I am not sure what the dish is exactly on these pistons, but it should put me around 9.5:1.  I could be wrong, though.  This is why I was thinking about zero decking the block.

I will probably be using headers, but I kinda want to use stock exhaust manifolds.  If I use stock manifolds, I am going to try to find some HO Camaro/Firebird manifolds.  I believe they are 2.5" output.  If I stick with headers, I would like to use the ball & socket flange.  I don't want cheapos, but I don't want to spend $600 either.  Ceramic coated would be preferred.  Has anyone used this header?  What brand, price, and vehicle fitment.  I know some have used mid length headers.

Carburetion is unknown at this time.  Quick Fuel makes a 680cfm Slayer that is supposed to be hot rod friendly.  My other option is the Street Demon 625cfm.  Let me know if anyone has used these specifically.
 

[nlauffer]

Update:

I dropped off the block, crank, pistons & rods at the machine shop to get cleaned up.  While talking to him we decided he would clean everything and check clearances.  He said the crank looks like a polish will clean it up.  I decided not to get a new crank at this time. 

When I asked him to deck the block, his response was:  save some money and use thinner head gaskets.  He said he would make sure the surface was true, but his opinion on this build was to use a .015 gasket.  I like the idea and think it makes more sense.  Some times I just have to here it from someone else or I'll take off down the wrong path.

As far as ARP bolts.  He said the rod bolts look like stock replacements.  I think I am starting to decide how to build this engine for real now.  I had all these grand ideas in my head, but once the work starts, reality comes to the front.

Before I left, I asked him about heads.  I saw some in the customer section, but none anywhere else.  He doesn't usually build to sell he said, but he has a set of RHS 180cc runner 64cc chamber heads that where given to him and another customer wants.  But, that other person hasn't been back for months.  At $450 I told him I'd take em.  Now I have to wait on him to decided whether the other guy will return.  I think that says something about the business he runs.

Header or manifolds??  that debate still goes on.  So does carb.

[Jason S]

It sounds like you found a reputable machine shop.  All things being equal, I don't see a major issue with the thinner head gasket.  If the block deck and head are straight, that shouldn't be a big issue. However, you may consider the costs associated with the gaskets versus decking the block and/or flat top pistons.

Do you know the "cc" on the piston dish?  The volume of the piston and head will allow you to compute the actual compression ratio.  With a stock deck height, you'll likely have some safety margin but may not gain the C/R you want.  If the piston is below the deck height, then you will have the cc of the piston plus the cc of the volume to the deck plus the cc of the head to calculate the actual C/R.

Not racing and a daily driver, you will probably be fine with the stock replacement rod bolts.

Since you said the truck will be a driver, headers overall give more horsepower and torque, but can be more troublesome (especially with cheap headers). Manifolds are generally trouble free.

As for a carb, I prefer the Q-jet for gasoline.  Other people will have other opinions. However, somewhere around  600 CFM will probably be adequate for your build.

Ultimately, the decision is based on what you want to build and how much you want to spend...

[nlauffer]

Part of my problem with this build is that I don't know exactly what cc the pistons are.  It was rebuilt 10-15 years ago and put away in storage torn back apart.  They appear to be nothing special pistons.  Some places I have found 7cc dish is standard and some kits have 12cc dish as standard.  If it is the 12cc dish, that is where I want to try to make up in the deck or gasket.  I have computed the numbers a few times, but I can't get anything for sure without knowing the dish and what I am losing in deck height.  I have used some generic numbers, but even those I notice vary on deck height.

64cc heads are a must for me on this build.  I am tired of low compression 76's.

[78C10 sleeper]

if your truck is an auto u may have to get a mild stall converter like a 2300-2500. and those heads should work well with that cam and add a nice dual plane intake with a 650 it should be torky

[Jason S]

There are ways to determine exactly what cc you have from the pistons. It can be tedious, but at the very least you can determine what volume you have to work with.

Essentially it involves assembling the short block on an engine stand, turn a cylinder bank to vertical, bring a piston to TDC. 

Take a piece of plexiglass with a hole drilled through it, place plexiglass over the cylinder ( cylinder positioned in the vertical).

Fill a buret or graduated cylinder and write down the filled measurement. Carefully fill the cylinder with water from a buret or graduated cylinder through hole in plexiglass until cylinder is full to bottom of hole in plexiglass.

To determine the exact volume of the piston at TDC, subtract amount of water poured into cylinder from original amount in buret. 

The same would apply to the cylinder heads. Decking the heads, valve jobs, etc can reduce or increase the advertised volume on a head.  Checking to see exactly what you are dealing with can aid in determining the gaskets used and other build parameters.

[nlauffer]

So it's been awhile, but I talked to the machinist a few days ago. He said between harvest and working on some irrigation motors he hadn't finished mine yet. Dang rural Kansas. Everything gets put on hold during harvest and the start of corn irrigating. He did say the crank will be fine, but he said the cylinders are too lose for the .040 pistons. It looked like someone re honed the cylinder to get rid of a little bit of ridge. He recommended going next oversize. I told him to go ahead. I asked about flat tops and he said it would be too much for anything other than stock cc heads. I told him that's what I thought but I was still wanting to buy the RHS heads he has. He told he probably would sell them to me. Still not a definite yes but I am starting to understand his personality now. I think when the day comes I will own them. So stock hypertectic it is. I'll find out what the dish is that way. I do like the idea of cc'ing the cylinder after short block is assembled. This way I get exact. He said I'd be around 9.5.
So with a .060 block, RHS 64cc 180cc intake heads, lunati cam (see above for specs), stock pistons (12cc I think), comp magnum roller tip 1.5 rockers, edelbrock or weiand dual plane intake, stock hei, stock qjet (most likely), stock manifolds, vortec serpentine belt setup, and worn th350 and 3.73 gears what can I look for in numbers.
Anything I'm forgetting or should change?  I think this will be a much improved, reliable build. And cheap.

I currently have 3.08 gears but I have a set of 3.73 and install kit waiting for someone to put in. Any takers?
Also looking at a Chance transmission rebuild for $650-$800. $800 includes shift kit, hardened internals, extra clutch plate, and torque converter. I thought about going one step up on cam and upgrading to 2000-2200 stall.

[nlauffer]

What are opinions on Lunati Voodoo cam?

What are opinions on RHS heads?

[nlauffer]

Sorry so many back to back posts, but I like to hear ideas and opinions. I'm not an expert and can definitely use the help.

I have purchased the brackets froma Chevy dealer for a 98 Chevy serpentine setup. I still need a new AC compressor, alternator, water pump, power steering pump, and pulleys. The brackets aren't too expensive especially since I can't get anyone near me to sell me used stuff.
What kinds of issues am I looking at with this swap?  I know I need to adapt AC lines and power steering lines and a reverse water pump which I believe takes slightly different heater hoses. What abou clearance issues?  How do I upgrade alternator wiring for the 105 amp alt from the 60?  Do I even need to? 

I have seen you can just take new and old power steering lines and splice together. Is there another option?
Should I splice AC lines the same way?  Do I need the newer style drier?
So many questions but I just am  not sure.

[Fairlane514]

I built a 1996 Vortec motor for my 84 and put the serpentine system on it from the same motor.  You can reuse the original power steering lines from your steering box, they with scerw right in  to the new P/S pump, so no need for splicing. You can also use your original A/C lines, just mount then horizontally on the new compressor. I bought all new original style A/C components and everything bolted right together. 

You will need an new lower radiator hose because the old one will contact the serpentine belt. If you install the old one, you will see where it needs to be straight instead of the bend that contacts the belt. Also get a thermostat housing for an early 90's truck, it will point away from the brackets and you can use your original top hose.For the alternator you only have to use your original heavy red wire and the small brown wire, the other red wire is not used. The heavy red goes to the large stud on back of the new alternator, the small brown connects to the second "pin" down from the top next to the locating "tooth."  When you look inside the new alternator plug outlet you will see what I mean.

A/C you will have to search for a pigtail to adapt your old harness to the new A/C compressor.

You also have to make sure all the holes on the front of the heads are drilled and tapped to accept the serpentine system. if you use some Vortec heads they are already drilled. You may consider the Voretc's they are 64cc and could handle your cam with a little spring area work.

You will have the clearance the alternator bracket if you are wanting to use a Qjet and the original metal line from the mechanical pump.

On the new water pump, I just capped off the outlet I didnt use, it will make sense when you see it.

if you want you can call me 281-435-7843  Steve

[nlauffer]

So my 83 GMC steering hoses will attach directly to the new 98 Chevy power steering pump.  Also the AC lines from my 83 will work on the 98 AC compressor?  Do you have a part number for the lower hose?

I am using RHS heads and believe they are already drilled and tapped for acc. mounting.

[Fairlane514]

I did the conversion to my 84, so it should be the same for your 83.  Its a Dayco hose and I am looking for the part number.

I can take some pictures and send them to you if you want.

Alos, I would try to find all the stock bolts and fasteners for the serpentine system, it makes it A LOT easier......check ebay, be specific for a 98 system.

[nlauffer]

Thanks, will do. 

So with a .060 block, RHS 64cc 180cc intake heads, lunati cam (see above for specs), stock pistons (12cc I think), comp magnum roller tip 1.5 rockers, edelbrock or weiand dual plane intake, stock hei, stock qjet (most likely), stock manifolds, vortec serpentine belt setup, and worn th350 and 3.73 gears what can I look for in numbers.
Anything I'm forgetting or should change?  I think this will be a much improved, reliable build. And cheap.

[Fairlane514]

Probably somewhere in the 300-325hp/ 380 ft lbs range.

Another thing to remember with a flat tappet camshaft, you will need a high zinc content oil. Without it you will be taking a chance on ruining to surfaces between the lifters and cam lobe. You can use an oil additive, I believe Comp Cams offers something and a few others.

[nlauffer]

I was looking for something locally, but its just a small Napa store.  What is your thought on running it long term versus during break in.