DIY 1.6 cylinder head rebuild/port and polish project
 

Hey guys, I've got a couple of spare 1.6's lying around and I'd like to experiment with some porting and polishing. I was planning on doing it myself just as a project, it doesn't really matter if I stuff up as I've picked them up for close to nothing over the past year.

So I was thinking just setting up a DIY flow bench with a shop vac but I'm a bit confused of how I'd go about measuring velocity of the air through the head.

I was initially going to start with just cleaning up the casting marks in the 1.6's head as there are a few flaws which could be cleaned up to improve flow. Also perhaps just a port match as well and polish up the exhaust ports, whilst leaving the intake ports as is so I don't ruin the characteristics of the air velocity and turbulence as it makes it way into the combustion chamber.

Does anybody have any pointers and tips especially on the DIY flow bench rig and what I'm missing out on?

dont touch the port "floors". clean from the cast marks up to the "ceiling"

I heard that somewhere, if I was to touch to port ceilings, would it be a good idea to clean up the rough edges on the valve guides?

Also, is there any way I can DIY a 3 way valve job or would that be too hard? I have access to a lathe

cant do a 3 angle on a head with a lathe lol

i didnt touch my guides as its not a race head but a dd/track car.


link

link

these should give you an idea of what your getting into

Thanks twibs! that really does help! So how does modifying your guides effect the operations of the engine?

valve temp will increase a little and valve guide life will decrease a little.

Oh okay sweet, so I've been reading a fair bit with some DIY head port and polish and I've found the best way to go for a DIY home job would be to polish up the sides of the combustion chamber, clean up the casting marks in the bowl, ie getting rid of the ridge, and polishing the exhaust ports to help with the scavenging effect.

Did you reuse the stock valve springs or replace them?

polishing per-say isnt really needed. get the exhaust side smooth 300 grit or so is good enough. keep the intake side rough 60-80 grit.

blending the bowls is nice but ideally done by someone whos done it for a living.

youll be fine reusing the springs just make sure you keep note of where they go and which side is up or down.

personally, i went with a full head rebuild so new everything

Cool cool, this motor if it is going to go into my car will only have to last a few months and its not my daily. I was thinking of skimming the head, adjustable cam gears and raising the CR up to 10.5 and run it solely on E85 and drop my 255" cams in. I hope to make at 130whp.

My proper build is a 1.8 with a BP4W which is getting the proper headwork with 275ish cams and a GT2560R

Do you have on intake and exhaust gasket?

Slide them into place. It surprised me how much extra material was there.

I ported to the gaskets both intake and exhaust.

Yeah I've got plenty of old gaskets lying around. Plan to port match, I still need to do a bit more reading into it as my knowledge is pretty vague when it comes to port matching and being careful not to remove too much material

For the port matching, just do exactly that. You dont want to open up ports too much and lose velocity on a NA motor. Don't worry if the gasket is alot bigger than the actual ports you are matching.

Twibs is exactly correct with the valve guide area. The amount you will pick up there is not worth the issues it may cause.

If your feeling real crazy you can unshroud the valves a bit. The easiest way to do this is to have a few junk valves turned down so they are real thin where they hit the seat and use them as the safety barrier for your new valve job.

Sounds like you have a bunch of 1.6's to play around with. I'd love to see someone actually do the Singh thing.

Yeah I do mate haha. I'll start a worklog when I strip the motor down and start the DIY goodness and post back results, pretty keen to get it on the dyno for tuning and see how much power I make :)

Hey guys, I'm going to start buying parts soon and I need help with choosing parts, there's so much to choose from!

My plans have changed a little, and I was thinking about bumping the compression up to 10.5 by shaving the head, and possibly ceramic coat the pistons to hopefully reduce/eliminate the risk of detonation since I'm seriously considering on slapping a GT2560 later down the track.

I'm going to be running E85 as the main choice of fuel, and with the MS3x setup with a fuel flex sensor and possibly meth and water inj, I'd like the flexibility to run RON98 pump fuel when I can't find an E85 station with just reduced boost and timing retard (5PSI instead of 10) via separate fuel/ign/boost control tables and at reduced power of course.

My power goal is 200HP, does this sound feasible? I spoke to an amateur car nut a couple of weeks back he told me I was crazy to boost on 10.5. And yes, I would be crazy to boost on pump gas, but E85 is a whole whole different story! What do you guys reckon?

Gates Timing Belt kit
Hondata phenolic intake gasket
Aftermarket waterpump (I've heard somewhere that aftermarket pumps aren't as good as genuine Mazda, this only needs to last me roughly two years/25,000KMs ish, will it be fine?
There will be the neccesary seals, ie front main, camshaft, cas, rear main, half moons etc.. which I'll just source locally.

So I'm hoping that all my spare 1.6's, that best case scenario, the pistons are within spec. So all I need would be a re-ring.

Now onto the bearings and rings choices..
NPR B6 piston rings
ACL Race Main and Rod bearings (Will I need these or will I be fine with just ACL OEM specs which are more than half the price?
ARP Head studs and main studs (again, do I need these? or just OEM spec?)

The motor will basically running 255* reground stock cams with HLAs, and 99% of its time on E85, I also have a set of COPs which I'll slap on to help me with cold start issues on our cold winter mornings, a coolant reroute is on the cards and the turbo intercooling piping and log manifold will be custom fabricated by a good friend of mine.

I already have a new stock headgasket, will that be fine or should I consider a cometic? I will be running adjustable cam gears to workaround the shaved head and timing issues. But all in all, what do you guys think? And what am I missing out on?

I havent heard too many high comp boost setups on here, but 10.5:1 is only the stock comp on a VVT engine. From the talk around here our engines arent very knock resistant, not like the newer better designed combo chambers.

E85 and 10.5 CR boosted to 10PSI should hold up though right providing a good tune?

From what I know, E85 is magical shit, its very knock resistant, but one thing to be weary of is that once it does knock, it will just give way without warning.

And on pump gas, knock it back to 5PSI tops with the addition of a meth/water injection? And also ceramic coating to reduce the probability of detonation, I'm aware that I'll always have the small safety margin but with these said precautions, can I reduce my chance of a blown engine?

By raising the compression ratio, am I raising the temps of the BMEP? and to reduce the probability of a knock, I need to cool the induction charge to safe levels? Sorry for the noob question, I just really really like the idea of a high compression boosted motor that will have similar characteristics to a 5.0L V8. And plus I haven't been able to find much info on high comp boosted motors

by your own coating material and coat the stuff yourself.
Coat the valves

Why do you want to bump compression and start doing more exotic stuff like coating pistons if you're after 200whp? AFAIK that's pretty attainable from a 1.6 by just upping the boost, and should still be pretty reliable.
What's your goal here?
If it's 200whp just up the boost until you hit it & call it good.

Just my $0.02