V-12 Engine into 308 Build, over on Grassroots

I think you're right Paul, it would be best to lap them on the block....which is at the machine shop. My fear was I had non-normal issues that would require non-normal corrective actions because....well, its the frankenferrari and nothing about it is normal after I welded the bajesus out of just about every piece of it

I would like to get the heads assembled but it might be better to wait for the block to return and lap the cams in place....teying to get my head around good vs perfect I guess.......

 

decided to start the morning by giving the intake cam journals some lapping love. The cams dropped and and spun free but the best I could measure they were on the tight side of good and there will be none of that this go around...this engine should really want 20w50 oil is the goal...not just in some place but that should be the right oil everywhere so everything gets the oils flow its supposed to get. So thats done.

Stewing on what Newman said that ideally the lapping is done with the heads torqued on the block. Wade told me that too...what's that they say, when you're at a party and someone tells you you're drunk you may or may not be drunk but when a 2nd and 3rd tell you then you know you're drunk......I'll hold head assembly until the block comes home so I can give the journals another quick lap and be certain and looking back at old pics that is the way I reamed them the first time so .....yeah do it right.

There is a bit of fall yard work to do, close the pool and such but I should be able to cut the 4 new valves to length and give all 48 a quick lap check to be sure they are seating right, assuming they are. Then mostly clean up the heads so just final lap and final clean left.

The shop reorg I did the other week has really turned out to be more helpful than I expected. Here is the view I now have from my work bench....very motivating.
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Cleaning uo the place does ad to the fun. I did the same some time ago. It is SO much better to work in a clean and organized space
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That for sure but something being able to actually SEE the car again makes the work seems a bit less like work.

 

Moved on to lapping because I really wanted to see how things looked...5-10 seconds with the smallest amount of compound I could put on and I think it looks really good with a clean line on the valve and seat.
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I did another 21 and they all look the same which bought me to need to finish the 4 new valves as they come as blanks before I could finish the exhausts and move to intakes. I mark them about .050" long with tape then chop saw leaving all the tape, then fill the length in the mill with a carbide cutter. They are all to length but keeper grooves will need to wait until tomorrow.
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Its been a bit slow and painful but head 1 intake valves are installed. Again as a reminder these are aftermarket race valves, springs, keeper intended for a Suzuki GSXR1300. The valves have 5mm stems and its a shim under bucket design with Ti retainers....about 1/2 the weight of OEM TR/308 setup and good to ...12000rpm probably., maybe a bit more.

The springs are good for .460" (11.7mm) lift and I only have .452" (11.5mm) so no worries...as long as they are setup right. I made custom guides for the 5mm stems and to locate the lower spring seat but didn't plan on the shims I'd need which raise the lower seat off the locating feature I put on the guides, which is why the need to the buckets I'm making. The important part is it's all good this time.
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I think I'm setting a new slow record of some kind....30 minutes per valve about? I'm so glad I'm not paying by the hour!
Just stupid little stuff...a bur here, the retain sits a little height after the spring is shimmed so it need a taller shim, when I replaced a bunch of valves why back it looks like the endmill I cut them with was dull and I didn't clean it up properly, finding a bunch of those...not horrible but not right.
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But head 1 is ready to have the shims set I think...yay. Again, remembering WHY back these valves are 34/28.5 not the TR 29/24 (iirc) so much larger. I spent a lot of time on the flow bench playing, setting up, more playing....and ended up with 456/550 sizes as this engine is basically that size....funny how that worked out.
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If you haven't done it already you should stress relieve it. I would go to the local powder coater and have them put the head in their oven and set it to 325F for a hour or so then let it cool over night. You could even cycle it again the next day then do your machining.

 

Will you harden the valve tips? Was there any sign of wear from when it was running?

 

The heads have been heated to 350 for an hour or more 3 times now...its part of process for installing seats. I did them 10 years ago, replaced a couple intakes and all the exhuast seats a few months ago then also replaced a few more intakes I didn't like a couple weeks ago.

Heads on the Barbie
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I don't think there is any why to harden them? The only wear was the photo I just posted...shinny in one area, particularly on the valves I hadn't lapped properly the last time around. Ideally the ends would be ground square to the stem so the shim makes full contact from day one but on the palled stems there in not more than .001" to wear before full contact so not perfect but there is very little place for it to change. On rocker engines they add a hardened lashcaps on top as the rocker would eat the soft valve stem but here the shim serves that function from what I've read....these just don't see rocker arm tip type loads, here its always flat and distributed across the whole surface......heck even the cylinder 8 valves that had been smashed to bits on the other end looked fine on top of the stem..... I just don't think its a concern.

 

For comparison, here's what the stems I lapped right the first time look like...no bright shinny spot just a little matte finish across most of the stem face as they should be.
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True. Thinking about it now I realise that the pressure is lower than rockers as the force is more evenly distributed and as the bucket rotates it wears the tip to match and the pressure is evenly distributed. I saw the wear rings on my old valves but they didn't measure any shorter than spec.

 

It thought I'd be posting a pic of 2 finished heads.....but on the very last valve I realized then remembered when I opened the spring kits there were 2 kits with 1 retainer design and 1 kit of another....they shortened it about 0.5mm and I measured the shorter one for my setup math. So I now have 16 springs set correctly and 31 set .05mm loose.....time to start over :x

Most are on the tight side so I should be able to drop in an .015 shim and be good SHOULD

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..... and the kids noticed a long dead mouse under the pedals......
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Did the math backwards in my head....it was pull it apart and cut .020" off the buck, remeasure, reassemble and 3 hours later....finished heads.
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With the stupid work done I did something IMPORTANT tonight.....and let my inner boy race SHINE! Now it's ready to install
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Awesome! Bet that feels good

 

It did for a litte while until I noticed the lifters look like ****. No similar issues with the cams that I see. I can lap them clean.....not sure I should but it's about a grand i don't have to replace them....it's always something
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Don't get cocky kid.

;-)

Lester

 

Will lapping them remove the surface hardness? Just something else to keep you from sleeping well.

 

That is a concern. They are not coated or anything like that so I don't think removing a couple thou to clean them up is an issue.....but why it happened to begin with remains. I spent a bit of time reaching out within my little circle this morning and the focus is on the fact that the valves were all hitting the pistons a bit as the most probable cause. With that fixed (which I will confirm by claying the pistons once the block and crank return) just cleaning these up and reassembling should be fine and certainly they will survive until I pull the cam covers to check the head torque and valve lash and then I either smile or replace them so very little risk and valves hitting, metal in the oil and not enough cam lube will all have been eliminated as possible causes leaving they were never good parts to start with or something more to do with hardness or surface finish mismatch with the cams. A couple days of lapping for me I guess.

 

just mic'd one....I'm removing 4 or 5 tenths to get them clean.

 

They are hard. I can't mark them with a screwdriver. I did the first one by hand and it took about 90 minutes. The next 11 I cheated and and :"lapped" on a running DA sander. I get 2 at most from a sheet of 40 grit, then 2-3 with the 80 grit...very light, they barely get warm. Then spend about 10 minutes by hand 100, 220, 600. Maybe 20 minutes total. so I now have 12 after about 5 or 6 hours total time...so paying by the hour it would be WAY cheaper to just replace them, but currently I'm time rich and cash poor so lapping it is. A very big vodka drink helps.....
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with 1 set of buckets done I decide to take a break from lapping and do the shimming....these l9.5mm motorcycle shims are so cute and light compared to the 30mm(?) ferrari shims
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I would polish the buckets and get the surface hardness checked (a local university engineering dept or tech college will often do it for free.) Zinc additive in the oil too.