Does anyone know the cam specs for a lb9?
and lt1?

trying to compare the two since i'm hearing good things about the lt1 cam swap.

thanks

 

 

so it looks like the tpi cams have more lift, but the lt1 cams have more int/exh duration....

 

I think you may be looking at the charts wrong. The weakest LT1/4 cam has more lift than any of the TPI cams. The LT1 chart is on top and the TPI chart is on the bottom.

Some of the TPI cams have a slightly longer duration than some of the LT1/4 cams, but they also have a tighter lobe separation angle. The LT1/4 cams all have wider LSAs to be more emissions friendly AND provide better cylinder charing with the radically different intake type.

With the exception of those provided in the 'B' cars (Caprice, Impala, Roadmaster, Sedan De Ville) the LT1 cams are at least effectively equal in duration and will more than outperform the TPI cams on the lift alone.

The last two items in the top (LT1) chart are Comp Cams stock replacements, not factory cams. Both of those work in an LT1 without PCM reprogramming. Of course, there are far more aggressive Comp and other aftermarket cams for both LT1 and TPI engines, many of which require ECM/PCM reprogramming, increased axle gear ratios, higher stall speed converters, etc. Personally, I would not bother replacing a factory TPI cam with a factory LT1 cam, except perhaps in a 305 with no heavy modifications. New87 did that and picked up some nice power gains, but reportedly is removing the LT1 cam in favor of an aftermarket for even more gains in his 305.

 

yeah, this is an all stock 85 305 tpi, with maybe some intake porting when i have time.

getting the cam for free, can't beat that.

not dumping much money in a 305. i know better than that.

how much of a gain is the lt1 cam worth? anyone have dyno numbers?

 

No dyno numbers, but new87 has time slips:

87 Z28 305 TPI, Auto,
LT-1 cam (@.50 418/430, 194/199, LSA 111);
roller timing set;
2.73 rear gears;
Gutted air boxes;
K & N fillters;
Dyno Max 3" cat back;
8.8 mm spirals, air foil;
BFG Drag radials;
170* Stat.

Old Best Time: 15.414 @ 87.47.
New best on stock tires: 15.006 @ 89.55.
- w/ drag radails 14.72 @ 92.10

 

your gains wouldnt be as good as others seeing as you already have a decent cam... 85 has basicaly the same specs as the l98..... also, you wont be able to use the LT1 cam anyways as its a roller cam and the 85's are not roller blocks.

 

doh