Powering an N/A 1.8 DOHC?

[DiamondBlue1]

Hey guys i had a question real quick and was wonderin if anyone could help me out.
I found a guy that works wit me that has a friend that works at a machineshop and when i talked to this guy about boring my engine, he said he would bore my engine to what ever size i need for $35 for all 4 pistons
My question is how big should i go to get the most power without going to far to weaken the block & what piston size should i get?
also how far should i shave the head of my engine?

[protégébob]

does that price included honing the cylinder after the bore?

[cat34evr]

My question is how big should i go to get the most power without going to far to weaken the block & what piston size should i get?
also how far should i shave the head of my engine?

I've heard 84.5mm is the max, but if you aren't going to increase the compression ratio or go turbo, there are 85mm piston sets available. Depends on the condition of the block, how you plan on driving, etc, etc.

Is the head warped? I would only shave it the absolute smallest amount needed to square it up. I think I have read you can go 0.020", but the increase in compression from shaving the head is tiny compared to using taller pistons.

That's a great price for machine work! I worked at a place that had a machine shop (non-automotive) and the lead machinist used to do machine work for cheap.

[DiamondBlue1]

Sorry for being late on replys. went out of town and had to take care of stuff. anywayz, what is honing? i want to get a big compression on my block. my block is in good condition. the head isnt warp but i want it to get resuface. i also want to prot and polish my head. how big should i get the head and valves ported out? one other thing, do they make smaller piston rods for our blocks? they said that might also help get a bigger compression. if they do what size and what do you guys think. thank

[Turpro]

if your looking for a cheap alternative than you can get the 10:1 pistons from a (i think)2001 miata. if you want more than that then you can get the wiseco pistons for a miata in a 11:1 and i think a 12:1. look at spending 400+ for those though

[DiamondBlue1]

Thanx bro. but do you know how big i should port out the head when i do a port and polish on it. Also i got some solid lifters off of an 97 mazda protege with a DOHC 1.8. all i need to do is install them in right or do i have to get the springs and valves too or just adjust them right in? any help info would do. i also got the injectors off of the protege. are they bigger than the 91 1.8 DOHC or just the same? thanx

[DiamondBlue1]

for i forget, when installing a exintake cam mod wit a adj. cam gear, what degree do i set it on again? i totally forgot and i just wanted to get reminded.

[Jho]

Thanx bro. but do you know how big i should port out the head when i do a port and polish on it. Also i got some solid lifters off of an 97 mazda protege with a DOHC 1.8. all i need to do is install them in right or do i have to get the springs and valves too or just adjust them right in? any help info would do. i also got the injectors off of the protege. are they bigger than the 91 1.8 DOHC or just the same? thanx

When you bring your head to the machine shop, tell them that you want to resurface it and port and polish it. They will know what to do.

Keep your fuel injectors. Both injectors have the same fuel injector rate: 250ml/min, so there will be no difference.

Check out this thread for answers to your exintake cam question:

http://www.wihandyman.com/forum/showthread.php?t=20392&highlight=solid+lifters

There is more to the solid lifter swap than you think. You have to install shims and measure valve clearances.

[DiamondBlue1]

thanx for the info Jho. it was really helpful. can any one else tell me on flywheel specs. im tryin to get the 9lb findanza but in case funds is tight, i heard that the flywheels on other bp from other cars have different weight? whats the lbs on the other flywheels on the other bp's? which is the lightest? thanx

[DiamondBlue1]

for any info my pro is a 5 speed.

[Tweeaks]

Yeah for the lifter swap you need the lifters and measure out your cold lash and order the appropriate shims. Don't know how much they are now, but two years ago they were ~ $5-$8 on average I think. Remember that's per lifter. I can't remember off the top of my head but I believe I spent ~ $150 on the shims alone. Remeber you need the cams too!

[Jho]

thanx for the info Jho. it was really helpful. can any one else tell me on flywheel specs. im tryin to get the 9lb findanza but in case funds is tight, i heard that the flywheels on other bp from other cars have different weight? whats the lbs on the other flywheels on the other bp's? which is the lightest? thanx

for any info my pro is a 5 speed.

Only manual transmission cars have flywheels, so we all assumed that your car was a 5 speed.

If you can't afford an aluminum flywheel, you can just get yours lightened at the machine shop.