Mouse cams

[dolt]

I ask because I have seen the Big Boyz Head Porting Site and was wondering if it was worth the added expense?

Big Boyz Head Porting Job
$299.00 ....Head Porting (inc perf Valve Job)

1) Send in your heads completely assembled
2) Heads are disassembled and checked
3) Heads receive a FULL port job (reshape and texture both intake and exhaust ports)
4) Combustion chamber surface is refinished (carbon, factory powder coat and rough surface is removed)
5) Heads are cleaned and receive a Performance Valve Job
6) Heads are cleaned again and assembled
7) You receive your heads back fully assembled and ready to bolt on your engine

OK, you want to get into the weeds.

1. You need to understand that the later OEM heads flow almost as good as Bean's "street" ported heads; not quite but close.

2. Torque is all about compression. Installing the 48s in an other wise stock or Stage I 96" motor sets corrected CR at about 8.9. A good target corrected CR for a street build is 9.3-9.4. To achieve that corrected CR, your head chambers would need to be measured and volume set at about 83cc; OEM chamber volume is 85-86ccs; I have seen some go 89ccs. So that means your chambers have to be measured and volume equalized and the heads decked to reduce the chamber volume to achieve the optimum corrected CR. That cost is not included in the $299 and will add $95 to your head work. Not much point in having head work done if one does not optimize.

3. Personally, I don't see the value in head work unless the valves are replaced with larger valves. Bean retains the OEM valves and springs. The OEM springs are fine but replacing the valves will add another $100 or so to the cost.

4. There are some "Stage I" head packages available for about $500 that include what Bean's street port includes plus larger valves, measuring and equalizing chamber volume and decking the heads for the target compression for the selected cam. So if you are seriously considering head work, you should be talking to a couple of other head porters that I can recommend.

5. As I said in my previous post, if you go down that road, you might as well start looking at other cams like TMans 577 or 590; S&S 570 or 585 or the Andrews 54 or 57.

The way I see it, you can spend the $299 for Bean's street port, replace your OEM head gasket with a Cometic .030" MLS gasket and with the 48 cams your corrected CR will be about 9.2 which is pretty close but, IMHO, the cost/benefit is not in your favor. Don't misunderstand, the street port and the compression bump from the .030" head gasket will improve performance but given the circumstances and the work involved spending a bit more for a full port job and a different cam swings the cost/benefit your way.

Either way will increase performance and Bean's street port is a good value for what you get; he does good work. I just think you get more bang for the buck going all the way if budget allows. As always, this is JMHO.:s

 

[spdrcr]

Thank you Dolt for the explanation. I just needed confirmation that the upgrade to the 48's would be the best, quickest, and easiest bang for the buck. You did confirm that! Thank you for your help!