[Mr Twister]

I'm making some minor changes to try to get my T/A to run better at idle an low rpms. Currently idles at 1400 and soots up the rear valance. During spirited driving it pulls hard for what it is. Its a 455 with 4X-7h heads, Qjet, RA3 manifolds, lunati 301/308 (231/240) .424/.424 lift (as reported by the seller). It has been suggested in other threads
I need more compression and the cam is a little big. The plan is: first rhoades lifters, then carb tuning and curving the distributor.
I got some new lifters from Rhoades last week and want to use the existing cam. With all the failed HFT cams lately, I want to coat the lifters. I got the lifters with the oil hole on the bottom. Recommendations are appreciated.
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[chuckies76ta]

Why is it idling so high? And if it's soot, that would indicate a rich mixture. I'd be curious on your timing setup and air/fuel ratio.
As far as coating lifters and the cam, I would think Comp cam lube should work fine. https://www.compcams.com/cam-lifter-...oz-bottle.html

[HWYSTR455]

Honestly, I would disassemble the lifters and clean the heck out of them before putting them into service, amazing the crap you will find in there.

Rhoads should use an e-clip, so easy to take apart. Do one at a time.

As for lube, me personally, I use assembly lube. I know a lot of people like the grey moly stuff and glob it on there, but assembly lube has less side effects and has many positive attributes. That moly stuff clogs filters fast.

Go to Summit or wherever and search for 'engine assembly lubes'.

I know people have a lot of different opinions on the lubes but IMO, the engine assembly lubes are the best to use. And contrary to popular belief, even if the carrier runs off, the lubricant remains on the part where applied.

Sealed Power and Permatex Ultra slick might be available in parts stores, both are good. There's no reason to buy some whiz-bang expensive brand, crazy what they charge for some of that stuff.



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[Mr Twister]

I was leaning toward a professionally applied anti friction coating like DLC. I plan to get a kit from Cliffs predecessor and going through the carb. I just got the car and only had a few weeks to drive it before it got stored for the winter.

[HWYSTR455]

I guess a friction coating isn't a bad idea, but it may cost as much as a cam and lifters.

I think if you do it right there shouldn't be any concern over a cam/lifter failure.


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[Jay S]

A DLC coating is going to run $600 or $800. Finding a place that will even want to do it is probably an even bigger issue.

The oiling feature on Rhoad uses is a groove on the outside. It isn’t a EDM hole on the face.

You might look into having the lifter Cryoed. It changes the grain structure and makes the lifters tougher, and is cheap to do.

Soots sounds like it is running lean, you probably have a tuning issue mixed in with how it currently runs.

The only Lunati cam I can think of that was .424” lift was their 744 musclecar cam that had the LSA moved into 108*. I think it was 224/236 at .050”. Or something close to that.

[steve25]

That cam in that size motor should not need to idle at 1400 rpm.

I have 3 important questions.

1) what is your initial timing at?

2) how much vacuum do you have at idle?

3) what is the motors hot cranking compression ?

[Formulas]

Clean well and use

[Mr Twister]

I did not attempt any tuning as i lost all my tools in a fire. So I've been buying stuff as I go. I had no idea that coating was so pricey. I need to open the box from Rhoades and see what the lifter feet look like, their website said super lube and i guess thats a groove on the side, I assumed a hole like other brands.
EDIT- I opened the box and no oil hole and they are absolutely filthy. Seller said cam was Lunati 10704

[Jay S]

10704 was the same RA3 musclecar replacement Lunati cam I was referring too. They were 220/228@.050” with a 110 LSA. It really isn’t a big cam in a 455, it should be able to idle at 600 to 800 RPM with a decent tune and a good lopey idle. It you use Rhoad’s lifters it probably won’t lope at all.

[steve25]

Also if the motor is idling and or running so rich that your getting soot on your rear valence then your not doing the rings and cylinder walls any good in terms of ware.

[HWYSTR455]

I'm in the camp of bad cam cores and lifters during a period of time causing cam wipes at start up. You can do all the wiz-bang stuff and still end up with a wiped cam. That's why I say take the chance and pull the trigger using 'conventional' methods, will be less waste of time & money.

If you have older stock type cam, during the time of the 'issues', then there's nothing you can do to prevent failure. But, you might get lucky.

Honestly, you're better off just buying a new cam, they corrected the issue(s), I no longer hear folks complaining about wiped cams.

I was assuming the high idle was for cam break in, so didn't think anything of it.


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[steve25]

If your going to try and reuse that cam by breaking in new lifters on it then don’t bother buying and using any moly type lube because the lobes have no pours any more to hold onto moly lube with.

Just get a greased based cam break in lube.

[PontiacHO]

I used Isky Rev-Lub on my new cam and lifter faces. Just enough to cover the surface. I was surprised to see what that looked like in the break in oil after the cam break in run. I know it’s a must to have it but I’d bet it has clogged up some oil filters and lifter galleys!!

[HWYSTR455]

The newer engine assembly lubes fill micro pours, the straight legacy moly stuff doesn't adhere as well, the particles are larger.

I did some homework on it one time, I even bought like 9 different kinds of lube and compared them, posted that info here, pics, etc. The newer stuff like post-2005 or so is light years better than anything before.

If you look at some of the reports it goes down to microscopic levels and shows the diff types of lube, coverage, adhesion, endurance, everything. Comes from F1 and space tech research. And it's not relevant to any one brand, independent, and tells you what to look for when shopping. Basically, most of the 'red' stuff is good, the green stuff was the 'intermediate' grades that were available in the late 80s and thru the 90s. It's 'good', but not like the newer stuff.


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[NeighborsComplaint]

Here's my $.02.

I am not an expert at coatings but they would seem intended to reduce friction like you find on piston skirts. Since the lifters rely on the cam lobe taper, lifter face crown and friction to rotate, an anti-wear coating would affect the rotation of the lifter and tend to make it want to slide (snowplow) without rotating. By design, the lifters are hard (steel) and the flat tappet cam is soft (cast iron) so the interface also creates friction between the dissimilar metals to rotate the lifter. The porosity of the camshaft allows it to retain the lubricant. It's a delicate balance.

Just use an assembly lube and don't overthink it.

[chuckies76ta]

Better still, go out and buy yourself a roller cam and lifters. Sounds like the new Comp roller lifters are working well.

[Jay S]

Originally Posted by Jay S

Soots sounds like it is running lean, you probably have a tuning issue mixed in with how it currently runs.

Sorry, that was suppose to say rich not lean.

You should look at the plugs and see how they are working. It could be they are a bit hot for the cam and compression.

[Stan Weiss]

I don't think that there is anyway that the cam that is listed needs to idle anywhere near 1400 RPM

See if you can borrow a good working carb, and see what that does to help your problems.

What is the engines CR?

As asked above do a cranking compression test.

Stan

[Mr Twister]

I think these are all great tips. The compression ratio should be about 9.4 to 1.