Ive got one of the 10% tin 20% nickel 4 bolt main 350 blocks that I plan on building to replace my 305.

I had been planning on making the standard 383 stroker motor although I was probably gonna go .040 rather than .030 but the more I think about it the more making something like a 302 10,000 RPM screamer would rock pretty hard. But once again I would at least go .030 so it would be more like a 306. But I plan on going full float rods roller cam aluminium heads etc...

What do you guys think? Which would be easier, make more hp, more torque etc? I was thinking the de-stroked motor would be easier cause you wouldnt have to deal with clearance problems, and as far as I know not as many people do it so it would be a little more unique.

Any feedback is apreciated.

 

Cheaper parts and more torque, 383. Building a high RPM 302 engine doing 10k RPM isn't going to be cheap or easy on parts. Unless limited by class rules to a 5 liter setup, go big.

JMO

 

I choose a destroked motor but i will not have to spin the rpms. If you are wanting to do a 10k rpm motor valvetrain parts are going to get really pricey.

All depends on what you want though. I went with the destroked motor to take away some of the tq and put up some more hp.

With costs of packages if that is what you are going to do the 355, 383, 396's are very off the shelf pieces but the crank is going to be the same cost roughly.

What is the car going to do? drag, street, roadrace, etc... whats the motor for?

Steven

 

Destroke for class requirements (cid).
Destroke when the cylinder head is a design restriction.

Otherwise build the largest engine you can afford. It will provide greater reliability at lower revs, especially for a street motor.

Take care

 

What the Dr. said.

An idea for you:

Build the 383, but tell your buddies that it's a 306. Now, tell the tach it's a 6 cyl., not and 8. 6500 at the engine will read about 8700 on the tach!

You'll be very quick and a hero to your buds. The best of all worlds.

Yeah, it's been done before.

 

If you were building a Winston Cup restrictor plate engine, with a minimum CID of 350 (or whatever NASCAR rules say now) and the max bore of 4.200 (I think that's the limit), would you build a 3.160 stroke for the lower friction hp and piston speed?

 

Not only would the 306 have less torque because less displacment but in order to get power at 10k you will need a big cam. The big cam will make the engine ilde above 1000rpms. To top it off youl need a +4500k stall converter. So all this together means the engine will be totaly unstreetable and be slower than a 383. What i would recomend is to build a streetable 430 hp-450 ft/lbs 383. You wont have to use any exotic parts like billit crank and rods like in the 306 or spend 2 grand on valvetrain parts to stop float. Theres no replacment for displacment.

 

I am running a v6 gauge cluster after my engine swap and it is awsome! Granted i don't know where the car is shifting but it is so cool to see it peg at 7k when you get on it. And the look on peoples faces when they see it is unreal too. Go for it!

 

You could probably find comparisons on the web for 377s versus 400s since that is more often talked about.

 

Alright well that was a landslide, I had originally intineded to go with a stroker but I was beggining to get intimidated by all the clearancing problems, and thought maybe I would cheat and destroke. But the way I figure it if I buy all my peices first and then take them to a machine shop they can take care of everything at once. I mean chances are they do these halfway often

 

Just multiply the tach reading by 6/8 or .75 to get the real rpm.

7000 = 5250, etc.


To carry this one step farther, it wouldn't be too difficult electronically to make the tach non-linear. 1000(engine) would = 1000(tach), but 3000(e) might = 4000(t), 4000(e)=6000(t), 5000(e)=7000(t), and 5500(e)=8000(t), or something like that.

Or, if a '60s muscle car manufacturer whose engines had a 5400 or so rev limit wanted magazine writers to see a 6200 rev limit, they could have just 'massaged' the tach inner workings. Hey, if you then mounted the tach on the hood where it was easily seen, these magazine guys would just go nuts. Could that really have happened?

 

LOL how did the thread regress into this I'll just change the thread name to all baout how to make your friends think your runnin 10 grand.

 

To echo what others (who are much smarter than myself) have said, I see no reason to use less displacement than you can reasonable fit into the cylinder case unless there's class limits. I'd much rather deal with the minor clearancing issues caused by a stroker than try to get a SBC valvetrain to live at high revs and still maintain longevity under street conditions.

It would be a riot to build a high-revving 302 sometime, but I'd save it for a "tossable" car, with a manual tranny, and that won't see much street use.

 

I have considered this as well. I can be parts binned too. Find an L99 (4.3L LT1) rob the crank and rods. Use the 350 pistons. You need to add weight to the crank to balance, but it can be done cheaply. The benefit. Well, on a stock head stock LT1 cam, you breather really really nicely. Pretty damn efficient, and good breathing past 6500 (stock LT1 falls off ~5500 RPM). GM engineers actually played around with this combo when they were developing the Gen-III engines (LS1, LM7, LQ4, LQ9, LM4, LR4, and LS6) and they were playing with bore/stroke combinations.

The reason why I thought about doing this is that I wanted to turbo as well, and improve fuel mileage. Finding T-03 turbos (Mopar 2.2, Turbocoupe) that would flow nicely for a 302 was easier than a 350. That, and I always want the best of both worlds. I might still build it for the heck of it, but I think for streetability and bang for the buck, go 383.....

 

i dont think i'd expect to use 4.3 lt1 crank and rods in a turbo app that would turn those kinds of rpm's. next to that its a royal b**** to try and get the stock ecm to run in a blown application and with the stock ecm taking a dump at 7k rpm unless you've got major money to throw away it wouldnt be as cool as it sounds. if i was doin it i'd just go with an aftermarket ecm the lightest billet crank i could find and some long aluminum rods and short pistons. no need in putting it together only to have it take a dump on ya the first time you smack 8500 rpms. and if i was doing it i would start with something close to what i wanted like a ford 5.0. i just dont see any point in all the money it would take to make a combo like this work. i mean granted if you had a light wieght car like a datsun z yeah then it might be cool to gear the wee out of it and spin it to 7k. i'll admit i do think it would be a hoot but not worth the money in my book.

back to the original question, if you're intimidated with the clearancing whats wrong with just leaving it stock. nobody said anything about that. a 355 might be a good comprimise for him in this case still a relatively high rev ability and still decent tq curve. lots and lots of off the shelf cranks that are tougher than hell too and can be had for cheap. just my .02