Jump to content
HybridZ

First question... engine build up


Recommended Posts

First off, Hi my name is Josh and I'm an alco… oops wrong board. You start things off with a joke right? Ok the fun part. I've spent the better part of the day, reading through the forums and trying to use the search function (I found a couple things I was looking for). And all I have to say is "nice". There are some really nice Z's in here with people that know what there doing. I look forward to picking your brains and hopefully contributing something myself. Oh yea my question.

 

I have a 1978 Datsun 280Z, currently I have a 305csb/T-5 combo. I have been running this combination for two years and it's time to something more to the car. I'm debating on destroking a 350 with a 305 crank, and running forged components. I would like to run this combination for a year to "break" in the engine, and then go with forced induction and fuel injection. My goal is a high revving low torque V8. Dose this sound like a step in the right direction for my goal? Secondly I'm curious on what the power limits are on the R200 rear end and the frame. Sorry to make this so long winded, any ideas, criticism, or flaming is welcome. Thank you

:D

Link to comment
Share on other sites

Guest Z-rific

Well, it's not that a smaller stroke engine revving quicker is a "falacy", it's just hard to prove either way. At what point does less friction and rotating mass exceed the ability to out rev a stronger, more powerful combustion...yada yada yada.

 

I think if your looking to rev high and fast, do it with proper valvetrain combinations. I think a 327 w/ roller cam and lightweight springs/rockers/flywheel, etc. would make for a nice high revving engine.

 

What gets a little trick is picking the right cam. You need to know where you want your power band. How often will you be in the 7000 rpm range vs 4000? Will your heads flow enough to support a cam that's power band is 4-7000 rpm?

Link to comment
Share on other sites

The idea behind building the power in the higher rpm, is to relieve the corkscrewing stresses on the chassis. The higher rpm would also help keep the turbo spooled, and help the lighter car hook up on launch off the line. I have never built an engine, but I know enough to surround myself with those who know what they're doing (I learn better with the hands on). I'm hoping to have a better understanding of it before it gets torn into. Where are the holes in my line of thing here? Thanks guys for all the info so far. :wink:

Link to comment
Share on other sites

RPM's don't keep a turbo spooled really. To get boost, you have to have load , ie: be accelerating.

 

Depending upon your turbo setup, the time from flooring it to boost is probably near to same at 3000 as it is at 5000, because the turbo is just goin' wit' the flo' unless the engine is under load, when it starts spooling.

 

The reason I say nearly is there will be some small variation, but at higher rpm cruising, the turbo may be spinning faster in cruise, but it has to speed up more to produce the same amount of boost as it would at lower rpms - pretty much a wash.

 

I stated previously that I wanted a real long rod 302 and turbo it. I still say this because I want something quiet and tame to drive daily, but when I stand on it I want to GO! I don't WANT a lot of off-idle torque that ci's give you...so stick with your plan...

Link to comment
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

×
×
  • Create New...