oil pan 4

iTrader: (1)

I just picked up an old C2500 suburban with a 454, TH400 and 10.5 inch 4.10 rear. The 454 is not staying in there because I have the 6.5L twin turbo motor I built that is less than 4 years old to put in, the 454 also knocks a little, only gets 7mpg and the radiator leaks.
The worst mileage my 6.5 diesel has gotten is around 14mpg and gets a little over 20 on the highway. Numbers this C2500 cant even imagine so long as that 454 is in there.

So that leaves me with a 454 laying around that might need a new crank.
It has 150,000 miles so I assume it will need to be bored a little.
If it needs a new crank I am thinking stroker crank. There is a machine shop right down the street from me that can do all the machine work, so I don't have to go to drag the block 100 miles to and from Lubbock.

Until then I want to play with it a little before I remove it. The Q-jet on there is running really rich. I want to replace it with something I know how to tune. For carburetor and intake I have an edelbrock 1405 to put on. I already have rebuilt and tuned these with my advanced tuning kit and wide band O2 meter.
I am not going to put the edelbrock on top of the cast iron spread bore. I ordered an edelbrock air gap intake manifold with oval ports.
I am pretty sure that wont fit under the stock hood of the Camaro later on but I will burn that bridge when I get there.

I would really like aluminum oval port heads to put on after the machine shop freshens it up. The smaller the intake port and combustion chamber the better for me since I want street motor.
But it seems hard to find anything with less than 300cc intake runners and everything seems to have 115cc combustion chambers. 100cc chamber aluminum heads under $2000/pair would be nice.
Anyone know of something I might have missed?

Reading the BBC header swap post it looks like 2nd gen Camaro headers are the way to go. Any chance they would fit on a C2500 too?
I would put 2nd gen Camaro headers in the C2500 before I pull the motor for my own enjoyment, if they will fit.
I can bend and build my own exhaust after the headers easy.

The Camaro has a TH700R4 that needs a rebuild. There is a transmission shop in Lubbock I found that will rebuild the 700 so that it can live behind a reasonable BBC when in a car. The TH700R4 has 2 things the TH400 does not have and that I really want, mainly an overdrive and a lockup converter. (I expect gas to go back up well over $3/gal before I put it all together)

AlkyIROC

Reading through all that it was really difficult to find out what you wanted to know but I'll give you info on heads.

115-119cc BBC heads are the best and I wouldn't recommend anything smaller than 310 cc runners unless you're building a stock replacement engine. Large open chambers to allow large 2.19/1.88 or larger valves so they won't become shrouded by the combustion chamber walls. The larger runner size allows more air into the engine as well. If you need a higher compression ratio than what a flat top piston will allow then use a dome piston to get the ratio you desire. The BBC canted valve head design works better with a dome piston than a SBC head design does.

My race engine has 119cc chambers. The heads flow somewhere around 400cc (rectangular port) and the dome pistons I use gives me a compression ratio close to 15:1 which works perfect with alcohol fuel.

Swap headers for a BBC into a third gen are never easy or inexpensive.

oil pan 4

iTrader: (1)

Yes stock rebuild is kind of what I am looking for but with a twist. I more or less would like aluminum heads for the weight savings and build an engine with torque and horsepower that emulates the legacy 454s of the early 1970s that made 380 to 425 horses and 500 to 600 torque. So nothing that hasn't been done before.

That's good news to me on the runners because 310 and 320 cc oval intake runners seemed to be most common.
I believe all the oval port aluminum heads I could find had 2.25 inch intake valves.

Raising the compression is a must here. The briggs and Stratton inspired 8:1 compression isn't good for anything besides reducing NOx, that compression that has to go up. The air is thin here, 4400 feet above sea level. Taking an engine from sea level to up here has about the same effect on compression as if you stayed at sea level, took you engine changed pistons or heads and lowered your compression by about 2 full numbers.

oil pan 4

iTrader: (1)

How much more room will an edelbrock air gap (7561) and edelbrock carb want to stick up above the stock hood?

I have always liked the IROC Daytona hood for some reason, think it give around +2 and 1/4 inch over a stock hood. Would that be enough?

polluxj

I am in Lubbock and been having trouble getting my 1989 Camaro started. Do anyone In Lubbock can help with this problem.

oil pan 4

iTrader: (1)

Ok finely the engine is just about done.
The final build is:
Edelbrock 650cfm carb that will be changed to an 800cfm after break in.
Edelbrock air gap intake, oval port
Bow tie oval port heads with 110cc combustion chamber, 2.25 intake valve.
-17cc kb cast +0.030 stroker pistons
Stock truck rods with arp bolts (installed by the machine shop)
Cast 4.25 stroke internal balance crank
Which gives me about 11:1 compression
Headbolts and main studs by arp
Compcams hydraulic roller cam retro kit with RE270XE cam.
File fit rings.
All balanced by the machine shop.
I am also installing twin 600 watt block heaters.

Now all I need to do is figure out ignition timing. I live at 4400 feet above sea level so the air is a little thin.
Any idea where I should start?
The old 650cfm carb is set up to run correctly in the thin air here, I may go one size up on the primary jets. That is why I don't want to just slap on an untuned carb on there and glaze the bores.
Before starting I am going to pump all the fuel in the tank out into my wife's car and put 5 to 10 gallons of fresh premium gas in there.

oil pan 4

iTrader: (1)

For the ignition timing info I can find seems pretty generalized.
For a 270 cam 10 to 12 base advance.
For this style of combustion chamber max of 34 to 37 degrees.
But this is an 11:1 compression engine. Mid 30s sounds like a lot of advance because that seems suspiciously close to stock setups. Or would mid 30s be alright with the thinner air?
This is my first high compression engine. I don't want to mess it up before I break it in.

The first fire up of this engine should be some time in September I hope.
All the machine work is done, machine shop is paid up, all the parts are in my possession. All I got to do is put it together and drop it in.

Just remembered I don't have push rods, unless the stock ones will work. I was expecting to need something besides stock length push rods.