viprez586

Speaking of unorthdox.

You think it's worth it to polish the exhaust valves? I think it would at least help with carbon build up.
Or time better spent on porting?

lobuxracer

iTrader: (2)

Intakes are where I usually see carbon build up. Exhausts don't seem to suffer as much for a number of possible reasons. I do the swirl polish you see in the pictures because it's pretty simple to do with a drill press and a die grinder and a few cartridge rolls. The real question around valves is what kind of service life do you expect? There are a number of things you can do to improve flow, reduce carbon build up (but they're only small differences, the real problem with that is thermal differentials and cam timing), and reduce the likelihood the valve will break vs. bend (bending is always preferred). I optimize everything for the application - the head above is for drag racing, so it has features I would not do to a street head. It's all about where and how you want to make power.

viprez586

Adziu

Good luck on the build Jake!
-Adrian (Chicago F)

viprez586

Small update:

Rods are discontinued, Rafi is working on sourcing a different supplier. I'll probably just end up re-using my OE rods.

CP pistons are also not correctly molded per Rafi so JE pistons (C/R 12.3:1) will be ordered shortly through RR.
Block is honed to 3.702"

O1GS43O

3.7" bore. does that make the stroke 3.5"? whats the length of the rod?

viprez586

Bore × Stroke mm (in.) 94.0 × 89.5 (3.70 × 3.52)

I don't recall rod length, it's published somewhere.

O1GS43O

5.681" Only a 1.613 stroke to rod. I would have guest it would have been 1.7 or better

lobuxracer

iTrader: (2)

Those ports look typical factory. Not bad in many ways, but the blend they do on the seats is always less than stellar. No evidence of core shift either, but that's hit or miss from engine to engine.

viprez586

I'll have to get some better pictures next time I'm there.

Machine shop said a 3- angle valvejob would be beneficial, would you concur based on your comment about seat blending?
Given how some looked, he even said they might have been the cause of low compression.

I should've done a CLT test, but when you find a dead cylinder you already know the name of the game and I wanted to be back up and running ASAP.

viprez586

Another small update:

JE pistons are ordered and 3 weeks out as mentioned prior.
Cylinder 8 bent the connecting rod, so that in addition to all the rod and main bolts are ordered.
Since the engine with be bumped in compression and heads having some port work done I opted to go with the RR racing intake with custom tuning, since they're tune scales the MAF to the larger size as they found a restriction and in the development of the RCF they changed intake diameter as well. I didn't want to run into a intake restriction issue for making the true potential of power.
Per FSM:
Connecting rod bend max = 0.05 mm (0.00197 in.) per 100 mm (3.94 in.)
Connecting rod twist max = 0.15 mm (0.00591 in.) per 100 mm (3.94 in.)

2013FSport

iTrader: (2)

The 3 angle grind angles go back to expected service life. Cutting the back of valve removes mass which keeps its temperature from esculating out of control when off the seat. The benefit is flow. So the question is, how much do they intend to remove?
The intake doesn't see the spikes the exhaust does and can typically handle more as it's getting cooled by the intake charge when off the seat. The exhaust is on the other spectrum being the gate for the spent gasses leaving the combustion chamber. That said, if you intend to run the laughing gas, you might want to leave them as hearty as they get!

All theory aside, I haven't seen these valves and don't know how much mass they have or the contact patch at the seat. There is more to this than meets the eye. Hopefully this will at least lead to better questions and explanations. G/L!

lobuxracer

iTrader: (2)

Factory cuts three angles. The Japanese never do single cut seats on anything I've seen. The real question is would you be better off with 5 or 7 angles, and with the rudimentary cut to blend the seat into the bowl, is there value in some reshaping/aligning/sizing.

The Japanese approach to sizing also differs from what I have found to work best.

Narrowing the valve faces is fundamental to improving flow, especially on the intake side, but you have to keep in mind they are now using cam timing to create EGR, so it is preferable to keep some heat in the intake valves to prevent carbon build up during street use. Race engines couldn't care less about this.

viprez586

Thanks guys, valve seats are just going to be cleaned up and valve surfaces as far (as polishing or removing material) are going to be left alone.
The intake bowl will be opened up some.
My bolts and 1 connecting rod just came in at my local dealer so hopefully I can get out to the machine shop sometime this week and see if they had a chance to go through the heads.

As for spray, I will probably want to get some miles on the car first, get the bugs(if any) worked out, and run some miles through the car to see if any issues will occur. If all is smooth sailing then it's dyno time. Sadly I never got a baseline with FBO stock tune, but I plan on using a local dynojet.

clarionguy

I see you are able to handle most of the labour on the car - the engine work looks like the shop is dealing with this plus the cost of the parts - I am curious what type of $$$$ we are talking about.
I am considering purchasing a used motor and just swap it - your images have eased my mind that I was scared no shop would be able to do the job or quote ridiculous prices.

Gonna give a quick BG 109 to see if I can clear out the carbon build up on my rings. If this does not stop me from chucking my oil out of my exhaust then I might just have to swap the engine.

Its too bad I have majority of the power upgrades and cannot enjoy it at this moment. anything above 5k rpm I start to fire my motor oil out of my exhaust.
PPE headers, Joez, larger intake RR racing, Tune etc etc.

driving the car normally there seems to not be much issue but been filling up a quart of oil per 1000-1500 miles.