my dirt cheap 454 build

[rumblebox]

I know the term, "cheap," is relative, but I'm used to LSX engines..... So I got a K20 with a 454 that has a subtle rod knock. So I'm going to freshen it up and add dome pistons, a mild cam, air gap, ebay headers, rebuild the Q-jet, and do some mild work to the 781's that came on it.

The plan now is to just buy a complete rebuild kit from summit, but I'm very open to cheaper options of good quality parts, if available.

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[bucket]

Your plan sounds pretty good to me!

 

[68post]

Bet a 489/496 is only A $100 more !? You can buy a Scat stroker crank cheap.

 

[rumblebox]

Bet a 489/496 is only A $100 more !? You can buy a Scat stroker crank cheap.

Im keeping the factory crank and rods.

 

[Don5]

It sounds like a pretty good plan.

 

[hirschdalechevy]

If you are having the heads done , I would try an find some early model ,(big oval) closed chamber heads ,(063 , 290 , 215 , 702 ,etc..) and get them done instead. They are not the best for flow but with stock pistons and a thin head gasket , (.025) you would bring the compression up to 9 to 1 or so which would be way better than what you have now. But that's only if you were to do the heads.

On the early heads dont forget they need seats put in for unleaded gas.

 

[Nasty-LSX]

be sure to post pics of everything. WE LOVE PICTURES!!!!

 

[rumblebox]

If you are having the heads done , I would try an find some early model ,(big oval) closed chamber heads ,(063 , 290 , 215 , 702 ,etc..) and get them done instead. They are not the best for flow but with stock pistons and a thin head gasket , (.025) you would bring the compression up to 9 to 1 or so which would be way better than what you have now. But that's only if you were to do the heads.

On the early heads dont forget they need seats put in for unleaded gas.

Heres an update on my build plans, since we can't edit posts here:

- bowl work and singh grooves on the 781's (1975 castings), poly locks, 924's(probably)
- 33cc domes (~10.6:1)
- .039 gaskets
- .02 deck shave to tighten the quench so it doesn't ping
- dual plane, port matched
- freshen then Qjet (or holley if the cam is hard to tune)
- 1.75" headers
- 3" x-pipe with bullets and 24" magnaflows
- flat, solid, around 290ish duration and like .6ish lift on a 112-114 split, 4/7 swap
- shot peened stock truck rods
- factory steel truck crank
- etc

 

[bucket]

I personally would want the compression down a bit if it's going to be street driven, maybe 9-9.5 or so. I'm also a firm believer in going roller cam these days. Yeah I know it's a lot of money, but a failed cam will end up costing even more money if it happens.

 

[rumblebox]

I personally would want the compression down a bit if it's going to be street driven, maybe 9-9.5 or so. I'm also a firm believer in going roller cam these days. Yeah I know it's a lot of money, but a failed cam will end up costing even more money if it happens.

10.5 is not high compression. Plus, compression=efficiency anyway. I will eventually go with a roller cam when i can throw more money at it, along with EFI, lighter rods, etc

 

[bucket]

You said it yourself, your an LS guy Big blocks make heat, if you don't want to deal with detonation on the street in the summertime, it would be wise to keep the compression down a bit.

 

[rumblebox]

You said it yourself, your an LS guy Big blocks make heat, if you don't want to deal with detonation on the street in the summertime, it would be wise to keep the compression down a bit.

Damned iron heads

 

[bucket]

Damned iron heads

I wouldn't blame it on the iron really, just the stout heavy ass castings. A small block can generally get away with a little more compression even with iron heads.

 

[rumblebox]

Typically yea, but the 4/7 firing order swap puts the hot cylinders in front, allowing them to get coolant first, along with the .039 quench and singh grooves. It shouldn't ping in the summertime. Of it does ping, I'll just bump it down to 25cc domes.

Im also putting huge E-fans on it and setting them at like 180F.

 

[rumblebox]

I'm basing the 10.8:1 with 33cc domes on the heads having about 119cc chambers like most machinists are reporting. I'll know for sure what pistons i need after I physically measure the chambers. If they're closer to 115cc as advertised, I'll use 25cc's and make 10.4:1.