FEOA Forums banner
1 - 20 of 25 Posts

·
Registered
Joined
·
373 Posts
Discussion Starter · #1 ·
I was wondering where i could get these for my 1.8. I want them for when i rebuild my engine. Also i was thinking about stroking the motor when i did it so i could get even more power out of it when i turbo it. I want forged rods pistons and i am assumingi am going to need a new crank if i am going to stroke it so i will need a new forged crank as well. If anyone knows where i would be able to find these items i would appreciate the info and i am located in KC MO if anyone knows a place around here. Thanks :-]
 

·
Registered
Joined
·
8,915 Posts
JE makes Pistons...you can get a set custom built for your car for like 500 bucks, thats what Donnie did in his GT...this will include the rods and rings I believe.
As for crankshafts, check around your town...there might be a place where you can take your old one and get it balanced and whatnot. I know there´s a place here in ft wayne called C&P Machine that does custom engine building...I´m going to end up giving them a call when I get my block so I can have em hone it, dip it in acid (to clean it further) and do the freeze plugs.
 

·
Registered
Joined
·
373 Posts
Discussion Starter · #3 ·
How would i get ahold of JE, is there a website i go to, and where are they located?
 

·
Registered
Joined
·
239 Posts
yo, liat time i check, yesterday, the was a set of pistond for the 1.8L on ebay for like $350 they had a C/R of 8.8.1

http://cgi.ebay.com/ebaymotors/ws/eBayISAPI.dll?ViewItem&item=2405819507&category=33623
 

·
Registered
Joined
·
1,346 Posts
If you´re going to stroke you WILL need that new crank you thought you´d need and you will probably have to have it custom made.

When I looked into it (still planning on doing it), the crank was going to cost about $3k and that was because my friend said he could get a hook up from the company that helped him with his 8sec chevelle.
 

·
Registered
Joined
·
911 Posts
I want some 11:1 pistons :( and some sport cams and cam sprockets.. This summer im buyin a new block and just buildin on that. I fear my engine is gonna blow sometime soon. It burns oil alot so i think the piston rings are fried.. and it has predetonation like a mofo(word to the wise...if ur timing goes out, make sure the place you take it to a place that will make sure the engine runs right after it has been timed...the place i took mine to didnt...noow i have pre detonation and i think it fried my piston rings...stupid f*cks)
 

·
Registered
Joined
·
8,915 Posts
Donnie had 11:1 pistons made. I think he´s willing to part out his engine and would sell them to you. Technically they were 10:1. I forget how he put it but he said they were built for an 11:1 ratio.
 

·
Registered
Joined
·
373 Posts
Discussion Starter · #8 ·
If the crank is going to cost that much couldnt i just bore it over and get lower compression pistons and get the same effect as stroking would?
 

·
Registered
Joined
·
911 Posts
Nope, those two techniques have different affects on the engine. Granted they both make horsepower, but not in the same manner. W/ boring it out, i believe its for using more fuel and more air to gain primarily torque acommpanied by horsepower, but with stroking an engine...that effect gives primarily horsepower with some torque.
so if u want overall alot of torque, bore it out. if u want more overall horsepower with little torque gain, u want stroke...
 

·
Registered
Joined
·
8,915 Posts
stroking will actually increase torque more than it will hp by further compressing the air/fuel in the combustion chamber (depending on how much of a stroke increase you make it). Boring will increase hp because you´re just burning more air/fuel.
 

·
Registered
Joined
·
911 Posts
thanks for clearin that up, i knew the stuff, just got them mixed. lol, i´m at work tryin to tech support computers so i get confused easy...doin 2 things at once.
 

·
Registered
Joined
·
373 Posts
Discussion Starter · #12 ·
But when you stroke it you are getting more air/fuel into the combustion chamber as well as compressing it more. What i am getting is with boring it you wouldnt get the increased compression you would just get more air/fuel into the combustion chamber.
 

·
Registered
Joined
·
709 Posts
If you bore the engine out and use pistons with the same design, you will increase the compression. You have a larger displacement being squeezed into the same size combustion chamber. this increases the compression ratio. for example if the displacement of one cylinder is 400cc and the combustion chamber is 40cc you have 400:40 or 10:1 compression. if you bore the cylinder out the displacement will increase. for sake of easy math, say it increases to440cc. the combustion chamber is still 40cc. this gives you 440:40 or 11:1 compression.
 

·
Registered
Joined
·
2,188 Posts
Since birddog addressed the bore, I´ll address the stroke:

<TABLE BORDER=0 ALIGN=CENTER WIDTH=85%>[TR][TD]Quote:

[/TD][/TR][TR][TD]
But when you stroke it you are getting more air/fuel into the combustion chamber as well as compressing it more.
[/TD][/TR][TR][TD]

[/TD][/TR][/TABLE] Generally, to stroke an engine you´ll need special pistons (with a shorter distance from the pin to the top) or to have your stock pistons milled down, if that´s even possible, to keep them from hitting the cylinder head. So the compression ratio can be decided upon by what pistons you choose.

One problem with stroking is that you reduce the rod/stroke ratio which means lower VE (volumetric efficiency). This is why F1 cars use long rods and short stroke. A short stroke means less movement of the piston (lower piston speeds) while the large rod/stroke ratio means that the rod will leave the piston and meet the crank at more efficient angles (more straight up and down than side to side). This allows for higher revs and better efficiency. When you stroke you´re forcing the piston to move faster and causing the rods to travel through a larger circle putting more stress on the crank and the bearings... although the additional travel of the crank also means more torque.

So, if you´re planning on building a high revving racy engine, avoid stroking unless you plan to deck the block for additional rod length. If you want better driveablity around town and like laying rubber strips, you may want to consider the stroke.
 

·
Registered
Joined
·
373 Posts
Discussion Starter · #16 ·
Ok, thanks i think i get it now. I guess when i rebuild my engine i will bore it over and put lower compression pistons in there to keep the compression raio the same for when i turbo it. Thanks beverboy and birddog! :-]
 

·
Registered
Joined
·
2,188 Posts
I may have sounded a bit biased about the stroking.

It does have it´s advantages, and if you want to build one you CAN get them to rev just fine without decking (extending) the block, but you´ll need lightweight forged pistons and rods to reduce inertia on the crank. It´s just that for the additional hassles and cost, stroking isn´t the way to go unless you´ve got a big pocketbook and a need to win some races.
 

·
Registered
Joined
·
709 Posts
Stroking a motor is not for everday driving. anyone who does is just wasting money and time. If you need all the power you can get at the strip when you don´t need to be able to drive 100,000 miles then yeah stroke the sucker and lighten the bottom end up. I tend to favor a mild overbore with good heads and intake. quality lightweight pistons and tuned exhaust. thats good for daily use.
 

·
Registered
Joined
·
19 Posts
When looking for parts for the GT enigne remember that it was used for a little bit in the miata. SO search for the miata 1.8 and you might find some more parts.
 

·
Registered
Joined
·
1,346 Posts
Yeah the 1.8L miata motor is the same base BP block except the waterpump bracket is different, but you can fab around that.

Either way, stroke or bore you´re increasing displacement.
However you can get more displacement out of a stroke. More displacement will increase both horse and torque, because you will be pumping a higher CFM rate.

THE MORE AIR IN THE MOTOR, THE MORE AIR OUT OF THE MOTOR, THE MORE POWER YOU PRODUCE....COMPRESSING THE AIR IS JUST HOW I CHEAT :-] [Artificial Cubic Inches]

My friend Rob thought we could get close to a 4" stroke with enough money for all the custom parts. Our goal is to get the 1.8L to a 3.0L :-o :p 3L I4....is that just sick or what? ;-)
 
1 - 20 of 25 Posts
Top