L98 should i bother building it

[montecarlo-ts]

ive been running what i was told when i bought it an LT1. after looking up numbers though i know its an L98. i dont know whats been done to it before i had it and ive only rebuilt the aluminum heads with crane gold aluminum rockers. it has an edelbrock performer intake and a holley 670 carb.the rest is stock though i believe. i was looking at the lt4 hot cam, 218/[email protected] and maybe a victor series intake with a new carb. should i even bother with it? anyone have any ideas on what carb and intake i should use, part numbers or links, and what rwhp im looking at if i do?

 

[khan0165]

I have a fairly built SBC with L98 heads. Read my specs below...

I do not know too much about the L98 motor has a whole, but I do know lots about the heads. These heads have 58cc chambers which is great for compression, but they have very restrictive ports. Even with larger valves and heavy porting, these heads will never flow as well as ones you can buy new these days. You can't get your money's worth from porting.

Even with a big cam, flat top pistons, tall single plain intake, and good carb, my engine is being restricted by these heads... With head technology these days, and such a huge SBC parts market, you can buy VERY good heads for very little... As little as $1000 for aluminum heads.

The L98 was a motor from the smog contious 80s, so it was probably not meant for serious horse power (just taking a guess here). If you plan to stay the SBC route, the best are the engines from the late 60s and early 70s... They had nickel addative in the casting which made them stonger, better for boring past 0.030... Many of these were 4bolt main caps, which I believe the L98 block is not. 4bolt mains are also good for strocked motors.

That being said... if you are looking to stay UNDER the 450 to 1000 horse power range, and want a well rounded engine, with decent fuel consumption, then a rebuild is fine with what you have. I think 2 bolt main cap SBC motors are good to 600hp before you send the crank thru the oil pan.

If you are looking to build a mild race motor (450+ horse power), there are better options out there...

With a simple change of heads, my motor can make a decent 480-500 hp with the current setup... but my ported L98 heads restrict it at 390-400hp.

The good news is, if you are feeling cash-strapped... the L98 heads fit on any pre-LT1 motors.

 

[montecarlo-ts]

yeah ive heard the l98's are 2 bolt mains, i havent dropped the pan to check myself. 400 hp or near that is good enough. id like to build a lsx block but that wouldnt be an option for years. im just looking to step up what i have for cheap but with the right parts. i dont know alot about engines right now, just the basics, so i dont know what parts work well with eachother. while its off the road i figure i should pull the engine to rework it and learn as i wait on a trans. thanks for the tips

 

[khan0165]

there is tons of knowledge base on SBC engines, in every shape and form. You're also not limitted to just this forum...
In either case, there are tons of knowledgeable people who'll be able to help you find the parts and combinations for whatever you want to build... whether its a cruiser, or an all out race car, and anything in between,

 

[79GP6.6L]

What aluminum heads are on your L98? Factory or aftermarket? Only the vette L98s came with factory aluminum heads. The F-body engines all got cast iron heads. Neither flow particuarly well, but the vette heads were desireable (to have ported) back before there was an abundance of aftermarket heads on the market.

 

[RITTER]

Those heads are horrible, you should just send those to me so you don't have to deal with them anymore

 

[nawlins-tim]

It ALL depends How fast is fast enough. There is no reason you can't get in a mid 12 second quarter mile with that 350. If that will do for now, go for it. Those heads are better than many stock GM heads but not as free flowing as a nice set of DART pro's. Its all up to how deep your pockets are.