Steve40th

Did anyone catch this show? They did a Lazer cam swap where it changed the firing order on cylinder number 4 and 7.
Just curious if any one ever heard of this and if it is capable of being done on a LT1 computer controlled car.
They gained some power, but I have seen where another engine didnt with this same kind of thing. I know GM changed the firing order on the LSx engines, and NASCAR has done this for years, but there in need of every little bit of power.

Old SStroker

Yeah, their 30+ hp gain seemed way too much to me. It's difficult to hold everything constant in a cam swap. A couple more degrees duration and a slightly different LSA or built in advance/retard could have more effects than the 4-7 swap. That's one of the problems when your sponsors supply the parts. Would you rush out and pay $90 or so more for 10 hp on a 500 fwhp engine? Probably not.

It's been done on LT1s. Sometimes it even helps.

Steve40th

Thats why I posted it here. I saw an article in a magazine where it was negligible. But this show said it was identical cam with the exception of 4/7.
Now if it made the idle smoother, that would be a bonus too.

96silverram

iTrader: (12)

I was also wondering about that 4/7 swap and what benefits it would really have on a LT1 if any ?

borninatransam

iTrader: (4)

ask the ls1 boys. standard ls1 firing order is 4/7 swap. look at the similarities and differences thread started earlier today. i dont even know that they make a 4/7 swap cam for an lt1 though. it would be an interesting comparison from one cam to the next.

MrCadillac

well, if they make any 4/7 swap hy-rollercams for a SBC, I think you can make it work for an LT1. In the article I read, it said that the ford 5.0 had the 4/7 swap already done. ALtho the ford way of listing the cylinders is different. I think it came down to if it was a max effort motor, that it balenced the pressure on the bearings better, so it was a worth while piece. But on mild cars, you would actually lose a slight amount of power. I know it was in a magizine, I forget which one. it was either popular hotrodding, hotrod, or muscle machines. I'll see if I can find it. they ended up using 2 sets of identical cams, in 2 different motors.

Chris 96 WS6

iTrader: (1)

They forgot to mention if the cam profile was different. I have no doubt there was more lift and duration on the swap cam.

And no I don't think its possible to do with an LT1. The easy answer would be to just swap the 4 and 7 injector plugs and plug wires, but then its going to goof up fueling once the PCM starts reading O2s and adjusting injector pulse widths.

Perhaps someone with a knowledge of PCM innards could physically modify it to work.

MrCadillac

http://speedtalk.com/forum/viewtopic...r=asc&start=45

check it out.