luckyou03

iTrader: (8)

Hey guys I'm home from basic training for 2 weeks and I'd like to finish assembling my motor. It's just a short block right now. I have

Bore size: 4.030"
Rod length: 6.00"
Stroke: 3.480"
Compression height: 1.260"
Dome volume: -3.5cc Flat Top Pistons with 2 Reliefs

My cam is the LE1.6 ( .573/.568 lift )

I'm looking at the Trick Flow® GenX (TM) Street/Strip Cylinder Heads for GM LT1 part number TFS-30400010.

I see that they have 62cc chambers and

Intake Runner Volume (cc): 195cc
Exhaust Runner Volume (cc): 75cc

I've read you need to get these milled to get a good compression ratio. That is fine. I don't have time to wait for a set of ported heads. I know I need to measure piston to deck height, but I don't know how thick of a head gasket I need to get or how much they need to be milled to get the correct chamber cc.

This car will see 99% street time and only a few times at the track. I will be running pump gas 93 octane.

luckyou03

iTrader: (8)

I did a little computing and I came up with this:

with the felpro 0.039 head gasket I will get

* Cylinder head Volume (CC) = 62.00
* Piston Top Volume (CC) = -3.50
* Cylinder Bore (Inches) = 4.030
* Cylinder Stroke (Inches) = 3.48
* Piston to Deck Height (Inches) = 0.030
* Head Gasket Thickness (Inches) = 0.039

Compression Ratio is 11.0 to 1
__________

With the impala 0.029

* Cylinder head Volume (CC) = 62.00
* Piston Top Volume (CC) = -3.50
* Cylinder Bore (Inches) = 4.030
* Cylinder Stroke (Inches) = 3.48
* Piston to Deck Height (Inches) = 0.030
* Head Gasket Thickness (Inches) = 0.029

Compression Ratio is 11.3 to 1

Does this compression ratio sound good? I'm not sure what an ideal compression ratio is.

Abdullah

iTrader: (2)

11.3:1 compression looks good.

i suggest you run the AI CNC 215cc TFS LT1 heads (which are originally the TFS 195cc LT1 heads) they are $2,495 from AI http://www.advancedinduction.com also with AI's custom cam and ported
LT1 intake .

or wait for the TFS LT1 21* head CNC'd by AI that will be available by late Jan or early Feb. which what i'm waiting for for my 1996 impala SS.

th3brandon

im doing a build now and have these heads...im running flat top piston and going to stay right around stock 10.8.1 or so

CNTLOSE

Whatever you get post your results and the price you came up with. I am just now starting to look into heads for my car.

luckyou03

iTrader: (8)

Well some of my calculations were wrong from the initial post. I have a 3.5cc piston not a -3.5 so that puts my compression to 10.1:1. So I need to get these heads milled to lower the chamber volume. I am going to call lloyd today and see what compression ratio he recommends for the le1.6 cam.

Ray@Nitrous Outlet

for street duty 11.5 - 12:1 should be fine