Engine build up

[elliotaw]

I'm finally after months of tracking down parts about to put my engine back together. I've had nightmares with the valves and pistons due to the distributor 'Fabre' in Sydney being the most useless bunch of people I've ever had the misfortune to deal with. Anyway, got a few pictures of the heads as theyve just come back from the machine shop.

Picture above showing heads with the new valves just resting in position. The valves were custom made by manley. The exhausts are +1mm and the stems are 1 thou oversize. Guides have been reamed and exhaust valve seats re-cut to suit the bigger valves. Heads have been ported and skimmed.

Close up view. I dont think you could go much bigger on the standard exhaust valve seats.....

Inlet port, not polished, but been advised to leave it with this finish. Ports have been matched to the inlet manifold.

Exhaust port..again port matched to the stainless exhaust flange.

I am no expert in engine building. I've built a few motors in my time so i know the basics. If you see something that I'm doing wrong or could be doing better, please say something, I'd appreciate any feedback. Cheers

Elliot

 

[Lextreme II]

Exceptional Job.... Absolutely Awesome..... Do have any more info on the oversize valves?

 

[elliotaw]

Not much to say about the valves. Manley in the US made them from their gen 3 blanks from some weird alloy that i've never heard of. They are a dimensional copy of the original 1uz valves in every way apart from the exhausts being +1mm and the stems +1 thou. I wouldnt say they are exceptional quality. The tips need cleaning up as they are slightly burred and unevenly chamferred.

Elliot

 

[elliotaw]

The machine shop who worked the heads said that the valves do not need lapping against the seats as theyve been machine ground to match the valve angles. I disagree strongly with that advice, I dont see why you wouldnt do it while its in this state.
3 weeks ago I had an accident at work involving an angle grinder and my left hand...nothing terminal but it's put my left thumb out of action for 3 months at least so its made valve lapping impossible....so I went out today and bought one of these --->
http://www.autotools.com.au/catalogue/product.php/10/49/449

Not the most amazingly engineered piece of kit in the world, but jeez, what a little beauty.... as disabled as I am at the mo, ive just been outside and lapped 5 valves in about 1/2 an hour....

Elliot

 

[Lambo]

hi Elliotaw, Yes that would make the job easier, for years i have used a old manual hand drill, just grab the stem and turn back and forth and lift every now and then, done in no time at all,and there is nothing like the seal you get when you do the job manually with Valve paste
Regards
Lambo

 

[Anaema]

i dont claim to be an expert in engines and airflow, but it seems pretty foolish to leave the ports so rough. maybe it will have the golfball effect, i dont really know.

 

[Toysrme]

I also like hand lapping them.
<- drill press
Quick, light hit of emory paper (If they've been installed to knock the carbon buildup off of them)
Followed by a quick cleaning with a de-greaser (Simple green on a shop towel, kept damp)
Then to go overboard, followed by a quick polishing
Then de-greased again to get the polish residue off (that would otherwise sit on the valve & burn - defeating the purpose in the first place)


Wish I could give you some quantafyable data showing hand lapping is OK, but I can't - other than years of doing it & never regretting doing it from 4-stroke R/C glow engines to cars.
(Admittantly that doesn't make it right & I've always been a big stickler for actual data & breaking molds/traditional things that just are not true.)

 

[bango]

Yeah,i agree lapping the valves are a good thing,leaving the port as is seems the way to go these days,have somthing to do with the swirling of the airflow which mixes the fuel/air better,i was told..
I was thinking why only 1 mm oversize on exaust valves?Is that the limit of the size that you could go?What valves springs ?How much did all the head work cost..?

 

[Zuffen]

My ported heads look just like those in the photos. Rough as guts but that's the way to get the air moving.

My head man said flow isn't as important as speed. If the port is too big the air speed drops and cylinder fill suffers.

The rough surface prevents a boundary layer of air forming and effectively making the port a smaller diameter.

 

[elliotaw]

Everyone has a different opinion on the surface finish on the ports. But, of the experts in the field I have spoken to, they all say the same thing....dont polish them shiny. We could argue about it all day and if you search this forum as I have done its been covered many a time already... Personally, I'd like to polish them, but I wont as the experts should know what theyre talking about more than I do.

The heads cost me AU$600 to get ported and matched to the manifolds. They werent flow tested though, but the guy who did them had previous results from a 1uz that he had done which looked impressive....comparing apples with oranges there a bit I know...

The original valve seats in the heads have some meat on them. +1mm looked fine to machine out of them, but I dont like pushing things to the extreme at the sacrifice of reliability, so thats as far as I went. Im sure new bigger seats could have been pressed in, but there goes the budget......

Elliot

 

[Lextech]

I personally will never assemble heads without lapping the valves. Once when I was a young mechanic I assembled a brand new Mitsubishi head with brand new valves, then installed it and got it running only to find out one of the intake valves was very slightly bent. I have lapped every valve every time since. Besides, I think it makes for a better job.

 

[bango]

Yeah,anything that makes for a better"head job" should be persued...I dont mind a bit of "lapping" for a good head job...lol...

 

[Zuffen]

Bango,

You may be sailing a bit too close to the wind there.

 

[tomvale13]

Ahh.. bango, your comment is only superseded by your name (For all i know, the comment could be the definition of your name)

 

[elliotaw]

Not much to update. Got all of the valves, uprated valve springs, collets and retainers assembled in one of the heads. Using nulon assembly lube on the stems. Found two of the inlet valves on the 2nd head had too much tide play in the guide than the rest so I've taken that head back to the machine shop to have the guides replaced with new ones.

Elliot

 

[WDoherty]

nice work, can't wait to see the results of the port/oversize job. Will you be cams? If so which? Is this an n/a app?

 

[elliotaw]

Yes, I'll be fitting new camtech cams. Not sure what profile yet. I'll search this forum and see whats been done and tested. Yes, it's for n/a.

Elliot

 

[Lextreme II]

Hey Eliot,

I also heard you got some after market bearings too. Is that correct?

 

[elliotaw]

Yes I did. Thanks to yourself. Got a set of Federal Mogal bearings on their way. I was going to source ACL bearings from Australia. I called ACL direct...they have the machine programs to make them, they have the part numbers...but get this....they've never run a batch or intend to !!!

Cheers again.

Elliot

 

[bango]

Hey Eliot,

I also heard you got some after market bearings too. Is that correct?

What after market bearing did you used?