Titan 1.5 roller rocker arms

Hey guys, for you gearheaded performance types and folks who may already have these roller rocker arms on your engine. I wrote this up in the racing section, but thought it needed to be added here.

Ok, the best ang for the buck for the A series 1275 in the way fo roller rocker arms are the Mini Spares Titan 1.5 roller tip roacker amr assembly, it a way better set u than the Harland Sharp set up and the 1.5 is a boost in ratio which is boost in camlift. Here's the deal with roacker arms, all rocker arms, roler or not, they move in a arc mtion and when they do they lose valve lift at the end of the lift stroke. In the case of the 1.5 Titan, if the shaft hiehgt can be raised a bit you can get some of that lost lift back.

My friend has benn building a stupidly trick (I mean that in a good way) 1380 street motor, and this motor has the SPV-3 cam whioch is about as radical as I would suggest for the street, and the 1.5 Titan roller rocker arm assembly. Now to get your "perfect" vlave lift, you would calculate camshaft lift x racker ratio - valve lash and that would be what you would get in a perfect world for vlave lift, well thats not the way it works most of the time. When my friend ran these number he was .050" short of his "perfect" valve lift, and this is when he called me for help. I suggested he shim the pedestals and see what he got, for a simple test he found some washers that were .125" thick, and just stuck them under the center of the pedestal for this test. The results were very good, not only did the rocker arm angle get batter, so did the pushrod angle and the adajustment hardware setting as well, and he gained .025" of his lost valve lift back.

When shimming the pedestal, there are many limiting factor involved, valve cover clearence, head stud lenght, so naturally on a given engine comprmises have to be made, in the cae of .125" shim here, that put him at the end of his head stud length, anymore shim thickness and he would need longer head studs, so this will be thickess shim we can run on this engine, but you can see form the second photo where the adjustment hardwar position had change and the rocker arm angle and pushord angle all for the better as well, and to add to that .025" lost valve lift was gained back.

Now he will need to make .125" shims from the a template pattern from the bottom of the Titan pedestals, complete with oiling hle for the oiling pedestal. The first picute show the Titan 1.5 with no shim, and the second photo show with the "test" washer .125" shim.

Purty! Too bad you have to cover them up with a valve cover! Tell us more about the engine...

I hear he's gonna have semi-hemi combustion chambers.
There has been some work on this head for sure.

John Moore said:

Purty! Too bad you have to cover them up with a valve cover! Tell us more about the engine...

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It stupidly trick John, there have been some mis-steps on my buddy's journay to get to the end of this motor and some stuff i probably would not have done, but he learned alot thru the process. First off he ordered some H beam aftermarket rod form a some little known Mini parts palce in Englannd, the H beam rods price were just too good for my budyy to resist, but when they got here, they need bbb-hoos of wrok to make them actually work, truns out the cats in the UK, had never made rods before, and probably should not anymore, but between myself and buddy machinist Bobby, we got them to work fine in the 1380, in the end it felt like we had made the rods Next my buddy decided to buy a racing friend of min up north moldex billet crankshaft, now a billet crank is no where near needed in a street engine, but you'd have to know my buddy to know whay he wanted one. He ported his own head, well actually head(s) the first one was a practice head if you will it ended up being a old 12G940 Cooper S head, they are notorious about cracking between the seats, and my buddy discovered that after he had ported the head, so he found another head and did it again Then he decided he wanted a zero deck engine block, but had not calculated his head's volume and ended up having too uch compression ratio, then out buddy Bobby relieved the head around the edges of combustion chamber to gain more CC volume to get the compression ratio back to a streetable compression ratio, I could on and on , but I won't, it will be a nice motor in the end, my buddy learned alot of lessons on this build, and I'm sure he would probably would do it way different if he did it again, but all issues have been worked out. Sometime we can get ahead of ourselves, luckily for him, he had Bobby and myself watching his back. He's going to have al the normal goodies, aluminum flywheel, venier timing gear, he's running the APT SPV-3 cam, 1.5 Titan roller rockers, Rimflow valves (larger intake valve) ARP fastners, and a DCOE carb.

He'll need every bit of all that stuff to keep up with me


David, yes I have the revised photo of the head, Bobby did a nice job of buying him a few more CCs.

Hey, I've been there myself, we live and learn, and for my buddy in the end it should all work well. Ok with that being said, this is probably why if you going to build such a high performance engine you should let a professional do it for you :wink:

Hap Waldrop said:

John Moore said:

Purty! Too bad you have to cover them up with a valve cover! Tell us more about the engine...

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<snip> Ok with that being said, this is probably why if you going to build such a high performance engine you should let a professional do it for you :wink:

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That is why I just stick a crow bar in my wallet and let
you pros do it. Changing plugs is about my technical skill
level.

Gundy said:

That is why I just stick a crow bar in my wallet and let you pros do it. Changing plugs is about my technical skill level.

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One of my phrases to live by as a budding mechanic:

"Always use the approprate tool -- sometimes the appropriate tool is a telephone and credit card."

drooartz said:

Gundy said:

That is why I just stick a crow bar in my wallet and let you pros do it. Changing plugs is about my technical skill level.

Click to expand...

One of my phrases to live by as a budding mechanic:

"Always use the approprate tool -- sometimes the appropriate tool is a telephone and credit card."

Click to expand...

I love it! I'm gonna steal that line.
:thumbsup:

So, Hap, I have a question.
If these rocker stands need a .125" shim, why don't they come with the kit, or why is the stand made .125" too short?


Seems they could make the stands .125" taller for the application, and sell it that way?

The height would vary by cam design. Correct?

Looking at it, to keep the rockers level and the length of the adjusters reasonable, one needs the shims.
Cam profile will cnage the ajustment, not the installed valve spring height and levelness of the rockers.

Gundy said:

I love it! I'm gonna steal that line.
:thumbsup:

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No charge.

TOC said:

So, Hap, I have a question.
If these rocker stands need a .125" shim, why don't they come with the kit, or why is the stand made .125" too short?


Seems they could make the stands .125" taller for the application, and sell it that way?

Click to expand...

Thats a really good question, I asked it myself a kazillion times about a kazillion different parts In a perfect world the shaft height in the pedestal would be higher to correct this, but it is not, it's common problem with all roller rocker arms, a engneering blunder if you will with in the design, but lets not let the stock rockers off the hook they too can benefit from this. Probably 95% of folks never even check their total valve lift vs what it should be, to know they are losing ratio thru lift, but as you see, you probably are and you can make it better.

What you can see in the two pictures up top that Hap included is a guide to how to address rocker geometry. Typically, and I really mean typically; if the rocker wipe, whether conventional or roller tip is biased towards the rocker shaft side of the valve stem, you need to raise the pedestals. If biased on the spark plug side of the stem, then you need to shorten the pedestals. In the middle is just right and the narrower the wipe, the better. One can Dykem or maker with a Magic-marker the stem and check for location. Sometimes you find the pedestals are not properly located for the rocker ratio and no amount of shimming will fix the problem. New pedestal time!

Also the picture shows a frequent problem found with heads that use the large diameter race springs (to get more seat and open pressure so you can turn more rpm without breaking springs). The under side of the rocker gets real close to the edge of the retainer. Sometimes, the rockers have to be clearanced even with shims under the pedestals. This is because of used up valve seats on both head and valve. Usual with old race heads. Even worse if trying to use 1275 valves in 948/1098 engines.

Most of these parts suppliers around the world who sell these roller tip sets to the general user, set them up one way, Adjust for the new rocker pivot location but everything else is virtually in STOCK configuration!!!!! Very little decked off the block or head, new valves, seats and stock diameter type springs, virtually stock type base circle on the cam, etc., etc. When I make my pedestals for the Harland Sharps I mostly use, I'll add an extra 0.100" to the height to adjust for machining of the head, block and for the valve springs. This all helps bring the geometry closer. Then if I need shimming, the shims can be made out of normal sheet metal scavanged from a carb heat shield or the like. If a really thick shim is needed, the rocker shaft locating screw tab makes good ones. Just remember to point the end near the springs to adjust for the cutouts of the spring seat.

Harland Sharp, Mini Spares, MED, Titan, whomever, the products are usually pretty darn good if installed properly and with a good design approach. Just remember that there is a difference between the 948/1098 valve locations and the 1275. Some brands are made a little differenct than others for the two engine types. If the set you have are the off-set roller tips, then they can be readjusted for the two engine applications. Shims and locaters also need adjusting for centering over the valve stem tips. Bushings tend to wear quicker with the off set roller tips and be prepared to renew down the road.

Hope this extra informatio helps. Those two pictures Hap included really say a 1000 words. Just got to know what you are seeing and why.

HTH,
Mike

Mike, you may want to check out Sean Brown's recenrt R&D with MGB roller rocker arms, he works with HS ad Titan, and talks about goementry, wwww.flowspeed.com, check it out, it's good read. I'll building a x flow head MGB bottom end to work with Sean's reworked Titan rocker arms, and his custom pistons for that motor.

At the end of the day, most all all rocker arm set ups lose a ton of lift during arc, and even more once we throw higher lifts at them. I worked with near all of them, right down to Yella terra stud mount set up for the MGB, which claimed it did deliver the ratio it advertized, it did not, we gave about .030 lift, nd needle to say with the set shimming was more of chore.

My buddy on his 1380, in the end, ended up getting precision ground .125" steel stock and making shims for his pedsetals, in the end he regained .030" valve lift back (he's got somewhere around .430' valve lift now) , but still is a good .025" off what the theorectical valve lift should be with his cam and 1.5 rocker arm, and in the real world, if you can get to within that margin thats pretty darn good.

Hap: Thanks for the tip on Sean's article. Will take a look. Always looking for additional information, techniques and learning.

I fully agree with you that with OHV engines, the convoluted valve train arrangement is not an optimal setup for getting all the lift that the simple math of rocker ratio times cam lift minus lash would predict. Spending the time to check and optimise each area is very time consuming but pays significant dividends.

Another additional thing that rarely gets addressed is push rod length. This affects pivot location of the adjuster ball and is the "other" arc that has to be considered. Between both ends of the rocker, there is a good bit of work that has to go on to get all the valve lift available.

Take care and I'll have to drop by and see this project. I'll buy lunch at Duke's. Needing a ham/pepper/onion sandwich fix soon.

Mike Miller

mmmmmmm...baked ham, pepper and onion....toasted. Sweet tea.
Had it for lunch today. That's some good stuff.
I'd dropped off my new studs at Alan's place and was going to stop by Acme, but Hap wasn't in. He wasn't at Duke's sandwich shop so I figured he and Fred were hitting their favorite lunch spot.
LOL...I brought home some pimento cheese, egg and chicken salads and veggie beef soups. Wife would have shot me if she heard I went by Dukes and didn't bring some assortment of
their fare.

Gundy said:

was going to stop by Acme, but Hap wasn't in. He wasn't at Duke's sandwich shop so I figured he and Fred were hitting their favorite lunch spot.

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I wish, I was at the dentist office, yeah I know I get dental for free (with the wifey working there), but thats still about as much fun as a kick in the cods

Our buddy's 1380. I think that is a Datsun 5 speed he rebuilt
lurking around.
It'll be like the old days when he FINALLY gets the Bugeye finished.
Now it will be two 1380s getting after it. If his wife lets
him drive it. She wants the Bugeye now that he has the Caterham.
Back then it was me w/ a 1275 and him w/ his Judson 948.
Should be fun running the twisties hereabouts.

That is one long shifter handle on that gearbox beside the motor hap. You going to mount that one up to the engine? Very nice rocker arms, you need a lexan valve cover on that head to see those purple rockers working. Good looking work on everything Hap.

regularman said:

That is one long shifter handle on that gearbox beside the motor hap. You going to mount that one up to the engine? Very nice rocker arms, you need a lexan valve cover on that head to see those purple rockers working. Good looking work on everything Hap.

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Our friend Alan is building the motor, with some advice
and assistance from Hap.
Alan did send me a pic a while back with a clear glass casserole
dish as a valve cover as a spoof. Wish I'd saved it.
I fell for the gag and asked where in the heck did he find a clear valve cover.
I don't think that shifter is going into his Bugeye.