Need some basic info.

[Anonymous]

Would'nt this be the right size. I think it's what I had on mine 280 ZX Turbo back in 82. http://cgi.ebay.com/ebaymotors/ws/eBayI ... gory=33742

 

[Anonymous]

just a question, but do the inlin 6 cranks have to be shot-peened if u want to turbo it?

 

[xctasy]

just a question, but do the inlin 6 cranks have to be shot-peened if u want to turbo it?

No, not at all. A turbo will reduce the need for High rpm if done correctly. The crank will suffer less load in a 200 hp Turbo 250 than a 200 hp non-turbo 250. The combustion pressures are more even, and the crank is under less cyclic load. The crtical loads that break engines are morespeed related, not so much hp related.

Of course, a 98 hp 250 will be under more stress with a 200 hp turbo, but not as much as a camed, carbed, and headered six producing 200.

The US crank runs a very heavy duty front snout, not shared by the Aussie 250 engines. I'll bet that it is even stronger than the Aussie 250's. Turbo'ed, Aussie 250 cranks are as tough as nails.

 

[Anonymous]

thanks xecute for the great reassurance, so all i gotta worry about is the valvetrain then, maybe get some aluminum roller rockers and a 260 deg. cam?

 

[xctasy]

The truth is roller rockers do diddly squat bar three things.

1.They allow your guides longer without wearing, and can be far more reliable if you have the right quality needle rollers in the ones you buy. 2.The valves are not hammered as hard, but you won't see any extra opwer out of roller rockers of the same ratio untill about 100 000 miles. On unleaded gas, you can use tighter clearances without hurting guides as there is less side loading.

3.They are durablity modifications for those who really want them.

The stock rockers should handle the racket, and are cheaper and easier to replace, and sometimes, there are very specific oiling requirements.

If you want to drool, read up on Azcoupe, Ricksmol, Jimbo65. They have used them on there Aussie 2V's.

They look a million bucks, don't cost a million bucks, but I doubt you'd ever need them even on a hydraulic lifter engine reving to 5400 rpm.

 

[addo]

One advantage of the roller rockers is the side load reductions, as XE referred to. With the significant protrusion of the guide bosses into the teensy log head valve bowls/ports, a set of roller rockers, shorter bronze guides and milling down (max 100 thou) of the guide boss in the bowl area, can all work in concert - flow, flow and more flow. I realise all this is big bucks, but thought it might be of interest...

Adam.

 

[Anonymous]

thanks guys, i figure instead of buying a header, i might as well turbo charge it for about the same if not a little bit more $$, but i want to make sure everthing in the engine can handle the turbo. there has been enough turbo info on how to install the turbo so i think i might be able to do that, but i certainly dont want to put too much stress on the valvetrain or anything else. my plans for the year are to upgrade my head to a ported and polished head with a custom 2BBl intake unless i can find a good one at the wrecker that has a detachable intake already (no luck yet), i would like to put in a new cam (possibly a 260 or 240 deg.) but i dont know if i should upgrade the rockers, cause that seems to be pushing the budget (but if it needs to be done then it will), then for the turbo i would like a fairly mild one with about 8 psi (would i most likely find this on a 2.0L?) right now i am saving up to get the front end replaced, hopefully this or next week.

when i get around to the turbo I'll be sure to post lots of pics and questions so i dont screw up. anybody know of a really good book on turbocharging (preferably for inlines cause i have a small book on big V8's) yea the $$ is starting to come in a bit faster now that winter is through, but i'll use my income tax to probably do the turbo (or get another car so i can afford gas )