4AGE porting - OST-033: Triyota Spitfire Mk IV-AGE

[oldeskewltoy]

On rare occasions my client's heads go into something a bit UN-Toyota....



The 1969 Triumph Spitfire: 1600#s... that is about 600#s LIGHTER than an AE86


with a rather un-inspired 68hp....

To put that in perspective... that is zero to 60 in 14.3 seconds(all 1600#s), while a stock AE86 GTS is good to do zero to 60 in about 9 seconds... @ 270+ kilos(about 600#s) more mass!

(I know.... I worked on Spitfire 1500 series when they were new .... yeah, I'm that olde)




So my client decided to mix in a little bit of twincam magic...




An oddball fact... this is one of the rare cases where using a 4AGE INCREASES the cars engine displacement by MORE than 20%


...... AND that is where OST-033 begins.....






More to come......

[fixeruperer]

do you have any before and after dyno comparisons on the same dyno with any off these heads that you do ?
just interested thats all.

[oldeskewltoy]

do you have any before and after dyno comparisons on the same dyno with any off these heads that you do ?
just interested thats all.

no.... dyno plots...

I do have some flowbench results, and I've been told by a few clients that they "feel" the difference... but as of yet... no one has run a before and after with any of my heads. My hope is Skippy's head/engine, OST-032, will see a dyno. No dyno before because of engine damage, but Skippy will be a stock cammed 4AGE powered AE82. I plan on putting Skippy on the dyno, so I can give you after #s, just not before #s



Based on my clients parts list, I expect about 125-ish whp, or about 145hp. So that is just about double the power of the original engine



As has happened a bit to frequently recently, the head the client sent me has mis-cast chambers... His is on the right....






So, I've sourced a largeport head that is in better shape, had it cleaned, pressure checked, and it is all ready for port work....




and work proceeds on #1 intakes....








more to come.....

[oldeskewltoy]

Chamber #1's progression...






#1 exhaust ports progress as well....






more to come......

[oldeskewltoy]

Been busy since last week... our house is now on the market....


....and this head is now 3 down... 1 to go!!!




bowls #4 and #5, mirrors of each other....




a bit of perspective for those that might need it.....






with any luck this will be off to the shop for its 3 angle and surfacing by Wednesday....



More to come......

[oldeskewltoy]

#4 exhaust port... showing mostly #7 bowl, and a bit of #8....



This now goes to get its 3 angle and once it returns, checking chamber volumes...


more to come......

[.T.]

& for anyone who is interested in the car build - http://www.triumphexp.com/journal/Gregxster

[oldeskewltoy]

So...... long time no report.........

The head was @ the machine shop for about 2 weeks, the surface was machined .012" (a moderate cut), and it received a 3 angle, along with back cut intake valves........




When I got the head back, I began the task of checking, and setting chamber volumes. Chamber #1 was a few tenths of a cc larger then 2, 3, and 4, so chambers 2, 3 and 4, grew to match the volume of chamber #1. All now are at 36cc. This will give my client a final static compression ratio of 10.9 to 1.



With chambers now set, the process of assembly begins...

A quick side note... part of the delay in my work was the client had sent me Supertech valve springs, and the Supertech springs require Supertech retainers, and Supertech spring seats....

Here is how a Supertech spring "fits" a stock spring seat, stock on right to show the difference.



Long story short, he chose a set of Toda springs.



So with springs finally solved, assembly can begin - Toda spring on far left




Half way through assembly....




and finally fully assembled, including the installation of the buckets.




Next... installing the cams, and setting valve clearances.....




So more to come.......

[oldeskewltoy]

I'm glad I went my route, then.. first supertech valves, with stock everything else, then TODA springs with the TODA cams. I'd have probably borked my engine by not realizing the incorrect fitment.

not likely.... the spring fits so poorly you would have realized the problem almost immediately... plus since the spring doesn't fit into the seat the spring would have needed compressing an extra millimeter, or two.... making it much harder to install them.


As to the Supertech valves..... that is a future flowbench project



But for now... that is still a future project


Back to OST-033....

The Poncams....




Once opened.... a warning to be careful on installing the cams without breaking them!




a bit more detail on that warning



I've YET to break a cam... but there could be a first time... some day...



Intake cam in, valve clearance on the intake side .20mm, or .008". Since I have a reliable caliper that measures in SAE increments, we will use those for our clearances.




If you look to the right, on the pad of paper, I've begun with shims that are .114", I then installed the cams and the first 4 measurements are revealed. I want a final measurement of .008, and the measurements are a bit large, so it looks like this side will need to run thicker shims then .114"



All 8 on the intake side....




and I've now confirmed... the intake side needs thicker shims. The center row of figures are the current clearances - nothing excessive(to worry about)

Just for a fun snap quiz... how thick was the thickest shim I needed on the intake side???



With the intakes now set, here is what .008" clearance looks like





And after all are set..... The intakes are 4 @ .008", 3@ .0085", and 1 @ .009" - the exhausts are 6 @ .010", 1 @ .0105", and 1 @ .011".

this heads clearances are within .001" - the OEM cam spec allow for .004" (int - .006-.010, Ex - .008-.012)




To my client.... Note both cams have distributor drives machined into them, to distinguish which is which, look back between cyl 3 and cyl 4 and each is marked clearly - IN264-8.15, EX264-8.15


OST-033 is now ready to be sent back to my client.......

[andrew_mx83]

Just for a fun snap quiz... how thick was the thickest shim I needed on the intake side???

#5 must have a 0.124" or 3.15mm by the looks of it. Thats a thick shim, dont think ive got any that big and i have a couple of hundred here. If you dont have one thick enough you can always cut the seat deeper by the same amount... might muck up your 0.1cc matched chamber volumes though


You might find this spreadsheet helpful, saves transcription and mental math errors. I find it real handy. Was built for metric but should work just fine in fathoms and furlongs...
http://www.toymods.org.au/forums/thr...=1#post1189391



Also, if you really wanna be anal about valve clearances, you gotta ditch the feeler gauges

[oldeskewltoy]

Finally got the engine back together. Here is a video of the startup! I edited and pasted 3 videos together so it is almost 5 minutes long. I initially had the distributor 1 gear tooth off alignment. You can skip ahead to 1:40 to see the startup. Once I got the timing set and the idle screws adjusted it ran great! I will need to change the main jets, it is running too rich ( 12.5-13 AFR) at steady cruise. Time to drive it and clean it up to get it ready for the cruise night and car show next month!

said video - ignition happens @ 1:48 - https://youtu.be/gnZU677inFk

That is one of the meaner 4AG idles I've heard.... best of luck with it!!!!

[oldeskewltoy]

zero to 60 in 6.06 seconds...... proof at 2:20