Jump to content
HybridZ

24 Valve DOHC head almost done!


Recommended Posts

Pump in epoxy through the water passages as a sealant against incomplete welds, and porosity. This is what the outfit I mentioned above does---this is for when they "metal stitch" water jackets together...if they can fix a water passage with 10-32 bolts securing 1/4-20 bolts lockstitched together, welding sealants should be a cinch.

Afterwards, heat the whole thing to 200 degrees and pressure test it by immersion, and youre done.

 

The headbolt should hold the respective parts together fine---I have an idea how the welding would be done by me, but it would require a lot of machine work to the combustion chamber, etc.. but that would be something that I would be secure in knowing had 100% structural integrity as if the thing was cast that way from the fac tory.

 

Cutting little windows on the outside to aqccess the inner parts is a good plan---but I would use more than 1/4 working space, and just weld the externals back in in chunks. Looks like hell, but you will have an easier time of it doing the welding.

 

Also figure a way to purge the internals really well with shield gas so you could really run a long electrode out in front of hte cup, and not worry about not shielding the internals that well. and make sure your waterjackets are acid-washed CLEAN!

 

Keep us posted. Love those photos, hi-speed at work is great!

Link to comment
Share on other sites

ok like tony pointed out I'm going to be cutting two construction holes inbetween the welds right between the valves. Also I'm pinning the oil passages together and milling chamfer on the exhaust side of the head so that internal jacket can be welded soild. To finish it up I'm going to face my sufaces and redrill the bolt holes. Thats the game plan sorry no pics.

 

 

 

 

tbs

Link to comment
Share on other sites

yah hows about a $250 welding job and $85 steel plate to hold it all together. And still not enough information on how to desing cam lobs so I can have billet cams turnned.

 

Guys if this is going to get done I need cam shaft help, For the first cam I want it designed for turbo applacation, that can pull to 7000rpm if some anyone can help me understand how to make them I'll get right on this.

 

I'm sorry that this isn't a happy update but it happens and the only thing I can do is keep pushing though till the head is done.

 

 

 

tbs

Link to comment
Share on other sites

I nust commend you on you efforts this is how big things get done, love to see the ole hot rod guys with a saw and welder. Getting those coolant passages is going to be a major task. One thing to remember is that the coolant is responsible for taking heat away from the hot exhaust valves. This is critical on a turbo engine, since this will cause preignition if it gets too hot.

 

From a reserch standpoint, if you are really hot and heavy about making this a real barnstormer ready for production. I would go about it this way take a stock turbo cam on the P90 and figure out the theortical flow through the port. You can probably get some real flow numbers if you did some searching. Then I would take that number and bump it up by 15% this should give a appeciable gain in potential power. Use this flow # to design you cam on the 4 valve head. Port Flow new= P90flow * 15%

 

Now to design the cam for the new 4valver you will have to start with the KA24's cam design as a base. Then you will have to make modifications to that base profile to go from KA24 Port Flow old -----> Port Flow new

 

Things to keep in mind that is to deal with individual ports for the flow numbers. You now have 6 of them on the KA24 head, so don't let the math throw you for a loop.

 

May have missed some stuff, hopefulley I didn't type something wrong when I did this quickly.

 

Go out and give er'

Link to comment
Share on other sites

sorry no updates yet, this is my last day of spring break so next week I'll be able to get back into the shop at school. But this week I've just been trying to get my car back together so I can drive it, I installed a ACT clutch kit , garret t3/t4E, and I'm building my full 3inch exhaust right now. :D so close I can't wait!

 

 

 

 

 

 

 

tbs

Link to comment
Share on other sites

Guest Nic-Rebel450CA

Hey TBS, what info do you need help with as far as cams? Do you need help calculating what lift, lsa, duration, etc. to use? PM or email me and I may be able to help. :wink:

Link to comment
Share on other sites

  • 2 weeks later...
  • 2 weeks later...
Guest vodkaboy

im going to have insurance money left over from my accident (doing the work myself saves money) and if its still rediculuously low price, ill buy one and advertise to everyone around my area if you want... that sounds so rediculuously awsome it hurts...

Link to comment
Share on other sites

Guest vodkaboy
Tbs' date='

Hey good luck on the head thing...hope you get her together and running soon, and on the whole making them thing, did you think of getting with edelbrock or world products or someone else and convincing them to cast the heads once you get the setup right? I would be really interested in trying it on my '78....another Idea....everyone was talking about the KA intake being for a long-stroke motor...why not do the same for the L-6? Let's say take an LD-28 diesel block,(with it's higher deck height like the LZ motors) get the diesel crank offset ground to 3.78" (or a billet crank)and use the KA con rods and pistons to end up with an "L from hell" with a displacement in the neighborhood of 3.8 liters, and take advantage of that KA head. I know I'm just speculating out of the box and don't even know if it can be done, but wouldn't it be cool?

I was also wondering about the possibility of increasing the deck height of the L-28 block with a custom plate, (with a head gasket below it) and use taller cylinder sleeves so the cylinder surface is sealed, then slap that KAx1.5 head on top and start showing 1JZ's that there's a new sheriff in town. Just thinking outside the box here, like all of us.

The timing cover could be sourced from an LZ-24 (it's deck height was in the neighborhood of NINETEEN MILLIMETERS higher than the standard L-block!)

That way a stroker could be built using the LZ pistons AND rods, :lol: would just have to get a custom crank made with the longer stroke.

I know, just shootin' the bull but wouldn't it be cool to have a "monster" L-series, being just about every other motor in town seems to have monster displacement these days (from the same external size!)

I'll look up the specs for the LD-28, if it's deck height is similar to the LZ-24 I'm definitely gonna try the "big-block" L-series idea.

Good luck and god-speed on that head,

later,

Bryan[/quote']

 

if im understanding correctly, you're suggusting a long (diesel) stroke, but you really cant bore the cyls out too awfully much, making this a very oversquare motor, which might not let it perform as numbers would assume... just thought i might pitch in my $.02. if anything i would be interested in a destroked motor (L24 stroke maybe), and rig the head/cam to let it rev in excess of 8krpm, now that would be fun to drive, especially with a turbo...

Link to comment
Share on other sites

  • 2 weeks later...
  • 3 weeks later...

well, i went to a bar-b-que this weekend at an engine importers shop, they had a couple of KA's laying around as well as a couple of RB's ( includign a "parts" RB26, those sick bastards) anyway, they had a set of RB cams out and I pulled the valve cover off of the KA head. wouldnt ya know it, it fits, besides being 2 cylinders too long. the spacing is there, the cam bearings are the correct size (KA bearing cap fits perfectly on an RB cam) so, I think I found some cams for this head. I'll try and get a pic up, but its probably a crappy one, taken with my GF's camera phone, lol!

 

McAdam

Link to comment
Share on other sites

well' date=' i went to a bar-b-que this weekend at an engine importers shop, they had a couple of KA's laying around as well as a couple of RB's ( includign a "parts" RB26, those sick bastards) anyway, they had a set of RB cams out and I pulled the valve cover off of the KA head. wouldnt ya know it, it fits, besides being 2 cylinders too long. the spacing is there, the cam bearings are the correct size (KA bearing cap fits perfectly on an RB cam) so, I think I found some cams for this head. I'll try and get a pic up, but its probably a crappy one, taken with my GF's camera phone, lol!

 

McAdam[/quote']

 

I have a spare set of RB26 cams (non useable) that are scored, but will be good for mocking up a head....

Link to comment
Share on other sites

you may want to contact John Williams of Williams Machine in Lake Elsinore CA.

I believe he was cutting bare billetts for cam grinders locally (Gude Performance, I believe). This would get you a billett, but you would probably have to supply detailed dimensions for the lobe centers and bearing surfaces. Then off to the cam grinder for final finishing of your billett.

Then again, if RB cams fit, why reinvent the wheel?

Link to comment
Share on other sites

Guest zline

you would then be able to convert to a RB style timing change and use a RB crank sprocket.

 

i would personally go to a big bore medium stroke long rod type engine

90mm bore

260z 73mm stroke

 

extended rods (have to do the math)

 

 

with high compression individual throttles and some step 3 camshafts...that would be pretty fun.

Link to comment
Share on other sites

well, I tried to send some of the parties here a few photos of a custome one-off head so they could post it, but between being "over quota", or "not liking sender" all my cool photos got bounced back.

Well, at least ONE photo got through, so maybe you guys will see something neat and unseen digitally ever before.

 

A one-off casting bought at a Swap Meet in San Diego CA a few years ago. You got it: a DOHC head for an L24 engine.... :D

Link to comment
Share on other sites

DONE! Thanks, look forward to seeing them here.

Those four are the only 1280x960 photos I could take when the guy had it out.

The rest are some 640x480 shots, and I can send those to you if you're interested in other closer up views.

 

I'm anxious to see what others here think about the head...

 

And that it was bought complete with the machining plates semi-finished at a SWAP MEET! (With Blueprints! :shock: )

Link to comment
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

×
×
  • Create New...