According to the TPIS insider hints book, they found that installing the 1.6 rockers on both the intake and exhaust reduced the idle quality. Has anyone done this on a stock L-98, and if so can you provide some insight as to how bad the idle is?

PS: Sorry if this has been asked before.

Thanks

Bob T

------------------
1990 Roadster

 

It is not that bad at all, it is a little choppy but not enough to effect any acessories.

 

Do you think it would mess up an emission test?

------------------
1990 Roadster

 

Do they help performance though? I saw a members site that said he had put on 1.5's on the exhaust side and 1.6's on the intake side. What performance gain did he get, I wonder?

 

On my L98, stock cam and shortblock, adding the Crane Crane Gold 1.6:1 rollers didn't make much of a difference at all in idle quality. Emissions were no problem.

Most articles or dyno's I've seen show an 8-12hp increase for using 1/2 1.5's and 1/2 1.6's, and as much as a 12-15hp change using all 1.6's. If used on a hotter cam, you won't see as much of an increase as you would on a stock cam since the cam is already allowing better flow thru the heads.

I did mine at the same time I did my heads, so I can't say exactly what the increase was. My stock cammed L98 and shortblock dynoed at 271 RWHP 345 RWTQ, got better gas milage on the highway than stock, and passed emissions easily. I did stay with the same 1.6's when I went to the 383. Even with teh cam I've got and the rr's, it still passed emissions an has a reasonable idle.

------------------
KevinP92Z
92 Z28 383 SLP cam,SLP headers,SLP 2ontheLeft,Trick Flow TW heads & pistons,Edelbrock base,Accel SuperRam,52mmTB,Scat Crank & forged ConnRods,MSD 6AL,SLP convertor,Baer 13/12" Track,Moser axles,Hotchkis,Genuine GM 3.42s,SLP HD Torsen,17x9" chrome SS rims
96T/A w/SLP Ram Air,SLP 2ontheLeft, Bilsteins, Baer, Hotchkis, Genuine GM, Torsen
76 4X4 Blazer 400TPI project