crank and rod questions
- Thread starter alec296
- Start date
- Joined
- May 26, 2001
Certainly it can be done, but it is not a good idea?
First, turning the rod journal that small will remove a lots of material which joins the off-set journals which will greatly weaken the crank in that area.
Second, that rod length will require an expensive custom piston.
First, turning the rod journal that small will remove a lots of material which joins the off-set journals which will greatly weaken the crank in that area.
Second, that rod length will require an expensive custom piston.
88 to 91 3.8 pistons show a 1.377 compression hieght which could work and are cheap. how weak will cutting the crank to this size make it? should handle 250 to 300 hp? the long rods should help with low end. stock buick 350 pistons are the same as 3.8 pistons so that does little to help
750H.P.V6
Brutal 6 Racing
- Joined
- Sep 4, 2001
'84 heads will work on a 225. In regard to your crank question if it's the crank from the 225 v6 it's an odd fire and should have 2.0" rod journals.
Neal
Looking to see what I can do with my 65 special. The 225 is stronger then a 231 so just thinking what I can do with what I have around the garage.Will a 3.625 crank fit a 225? Maybe a stroker with ported 84 heads and a 4 barrel. I'm not looking to put a intercooled motor right now just some more power.
dr_frankenstein
Mad Scientist
- Joined
- Mar 17, 2008
[quote="alec296, post: 3324500, The 225 is stronger then a 231.[/quote]
where did you hear this?
where did you hear this?
ek02
Well-Known Member
- Joined
- Jan 31, 2008
Horsepower rating for the 225 with a 2 barrel carb was 160 HP. The 1975 231 was rated at 110 HP. The rating procedure may have changed during that time. I think a late model 1980 or newer 231 has more power than a 225 due to a better head design, and will make a lot more power when modified. The high port 231 heads will bolt to a 225, but according to Pat Ganahl's V6 Performance book, water leaks are possible. If you used a 3.625 crank, you would have to change the engine over to even fire and use custom pistons, unless you found a odd fire stroker crank. That means the cam, damper,and distributor would also have to be changed to even fire. I think there is a difference in cam bearing diameter also. You could also just port and mill the 225 heads, change the cam, intake, carb, and get a set of headers all made for the early engine. A complete engine change to a 4.1 would be a much cheaper and better option, and then you could modify from there. After you do all that work and spend all that cash on the N/A V6, a stock V8 will have as much power.
dr_frankenstein
Mad Scientist
- Joined
- Mar 17, 2008
The problem is there is no fun in a NA build... particularly with an odd fire. Takes crazy compression and heads to make any usable power. Ask around the B4B section, lots of NA experience in there.
Well limited fun. In a big heavy car not much.
Maybe we should start the conversation over. What are the goals for the car? What will be the main purpose (driver, race, etc.)? What is your budget? And finally, what are your expectations? Going N/A with a V6 isn't all that cheap if the goal is 400HP for example.
Maybe we should start the conversation over. What are the goals for the car? What will be the main purpose (driver, race, etc.)? What is your budget? And finally, what are your expectations? Going N/A with a V6 isn't all that cheap if the goal is 400HP for example.
ek02
Well-Known Member
- Joined
- Jan 31, 2008
One HP per cubic inch is realistic, so figure 225HP on a 225. To get 300-325, you will need a stroked 4.1 with a roller cam and good heads. To get more than 1 HP per cubic inch, a 225 would need very high compression and a good cam and heads, plus all the other parts to go with a radical engine like gears and a converter to make it driveable. If your budget will not allow a 4.1, I would build the 225 with a Holley or Offenhauser early intake, a 500 CFM carb, a cam with 210-224 duration at .050 and a 110 LSA. Port the heads and open the valve pockets. Find a set of early headers and get a looser converter like a 2500 RPM stall, assuming you have a 3 speed automatic and not the old 2 speed. Use some Hyper pistons that would give 9.5 or 10-1 compression. It would be streetable and not too expensive. Keep in mind that a 4.1 with a stock stroke would look almost the same as your 225, and would only cost a little more to build since you would have to buy a used engine. It's easier to find parts for the later design. Good luck, and have fun no matter how you build it. I would recommend a 100 shot of Nitrous to get the HP up where you want it, but it may eventualy cause you some grief and $ in broken parts.
20psiofevil
Active Member
- Joined
- Feb 10, 2013
A ford 4.2l will get you there with a cam swap and a bump in compression. My friend made 280rwhp through a t5, .600 lift cam, 10.5:1 and cleaned up heads. Stock heads flow 210-220 intake @ .600.
Anyone know the weight of a turbo crank and stroker crank for comparison? My scat cast steel crank weighed 44lbs.
Anyone know the weight of a turbo crank and stroker crank for comparison? My scat cast steel crank weighed 44lbs.
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