is it a roller cam?

 

Is the chain on?

 

Any resistance when turning without the timing chain? Could be bent a bit...

 

Not sure what you mean by the quotation mark after the number. That means inches in my world.
I do know that some aftermarket aluminum covers can be thin and give false readings.
Also when attempting to contact the tech department of a cam company I would call, not write.

 

Sorry guys missed the responses...

Since we were talking about thrust, I figured people would know we were talking thousands... Hydraulic roller cam. Went through the whole deal again, thrust is only when the cam moves forward in the block. Lifter rides just slightly forward of center of the lobe. Bottom gear is square to crank, flush and aligned with top gear chain is on. The Straub guys are busy, we had several questions so we wrote them rather than call. Wanted to get the motor together so we turn where we always get help here!

57Chevy

 

Hi "57", seeing as you're using the MkVI platform someone should have recommended using the cam thrust (retainer) plate setup that the block is already made to accept, there would be no issue with cam end play or the positioning of the cam in the block??

(Add) The lifters on any roller platform should be reasonably centered on the lobes!

Thanks, Gary in N.Y.

P.S. We now do a number of our retro-hyd roller builds, both the SB's and the BB's using the bolt-on thrust plates. Makes life really simple nowadays! No more buttons or chasing end play, basically just bolt it together. Here's a shot of the plate and timing set we now use.

 

Is there a "good" chain set to use with a gen VI that will allow for use of the 1x cam sensor (sensor in the timing cover, cam gear has a raised area 1/2 way around out by the teeth)? I've look and all the sites I can think of and can't find one.

I'm doing a 540 with on a bow tie gen VI block and am using the retailer plate. Also have a 24x wheel on the crank snout with sensor in the timing cover as well. Right now I have a new stock 1x timing set but wonder if it's up to the task?

Should add, using coil near plug so there is a Mallory plug in the distributor hole just to drive the oil pump.

Sorry for the thread hijack, fee free to PM to save the thread from getting sideways. I only posted here as others may use the search function and may also like to know

Hi "57", seeing as you're using the MkVI platform someone should have recommended using the cam thrust (retainer) plate setup that the block is already made to accept, there would be no issue with cam end play or the positioning of the cam in the block??

(Add) The lifters on any roller platform should be reasonably centered on the lobes!

Thanks, Gary in N.Y.

P.S. We now do a number of our retro-hyd roller builds, both the SB's and the BB's using the bolt-on thrust plates. Makes life really simple nowadays! No more buttons or chasing end play, basically just bolt it together. Here's a shot of the plate and timing set we now use.

 

Check the end play with the chain off.

 

Thanks for all the replies on this one. We intentionally went away from the Gen 6 cam retainer system. Although that was the original plan for the cam we were using, the one that has since been replaced.. Since all the parts were already in hand, the new cam supplied by Straub was using the cam button setup.

We will check on the thrust without the timing chain in place, that seems to be a good idea to do.

Although, even if it proves to be what causes the cam to snap back rearward in the engine, not much we could do about that.

So let's say we have to live with the 10 thousands thrust, all in one direction -what issue might arise? Once all the new parts are broken in, would the cam be able to walk around enough to change the timing, cause excessive wear to the block?

Thanks!
57Chevy

 

Hi "57", it appears you went from what would have been a fairly straight-forward assembly with not one single issue to opening the proverbial "can-of-worms" by eliminating that thrust plate retainer setup. Doing this for a living this makes absolutely no sense to me but it is what it is now for you?? I would have done some add'l homework before "pulling-the-trigger", someone should have given you a "heads-up"

You need to get tighter than .010" end play (preferably .003" nominally, this is what the bolt-in plate would give you) and now it MUST be "fixed" with the cam button, this it how it's done in your situation now. I would have recommended against using the older button setup. If you don't have few decent tools (dial-indicator, etc.) to check all these numbers accurately it will come to bite later!

(Add) Also like I stated in my earlier post the lobes should be reasonably centered over the lifter bores? If they are not it may be an indication of an add'l existing problem??

Just my own opinions here.

Thanks, Gary in N.Y.

P.S. To Allen above, that plate/chain setup in the photo is now inside a MkVI build with the factory t/cover in play. We aren't using any cam-sensor but I believe it would fit with all the factory pieces at the front, not 100% certain though! There was minimal (very minor) interference between the chain and the MkVI cover but it was easily taken care of.

 

Checking with the chain on could be part of your issue. I think you want to set end-play with no chain installed.

Gary - why does it need to be 0.003"? I was always of the understanding that it just wasn't that critical, and that anything from .002-.012 or so was generally acceptable.

 

Hi "nova", the .003" number is one that is pretty much "built-in" when you use almost any cam retainer plate setup, whether it be a Ford, Pontiac, etc. This is usually a "fixed" number.

When you set it all up using a conventional button you can change that number to any one desired. In the past and now we still set most of ours in the .002"/.005" area. You really want to keep as much control on the lateral cam movement as possible. If you choose to run a roller cam button AND a Torrington timing set I wouldn't be afraid to run .000".

No builds would leave here with over .006", that would be the limit for us.

Thanks, Gary in N.Y.

P.S. On the BBC's using a retainer plate is fairly easy as most castings have always had the "ears" (for the 2 bolts) cast in place, just drill and tap them and your set. The early SBC castings were all but nearly impossible to use any cam retainer mounting plate. Most recently we conquered this issue and are now using the plate on many of our SB builds. Our only limitation is around the cams that are available. It has made building our 100% SB stock-appearing (early) resto units on the retro-roller platform a pleasure to do. On either platform, SB/BB, we drill, tap, and assemble, cam end play is now taken care of by design, no issues!

 

If the chain is on it will probably be a snug fit. As soon as you try to pull the cam gear outwards the chain will pull it back in because pulling the gear out is trying to stretch the chain. It just "snaps" it back in as you say in your first post. So just remove the chain and then recheck the play.

 

who is TRE?

 

Thanks again to all that have responded...

TRE is TRE Racing engines. A well known big HP engine builder. We turned to him when we decided to do the build for his recommendation on what we should put into the engine. Our mistake was just telling him that we wanted to make 800HP plus, and nothing about the intended use.

It wasn't until we ran into a piston to valve clearance issue that we found out we had parts that "were too good" for our needs. Scott at Straub pointed out the issue and in our minds pretty much saved the engine, since the path we were on would have damaged the whole build. During that time we also found out the cam we had the Mutha thumper evidently was a very poor choice for what we wanted to do with the motor.

Straub had a great reputation here on the board and from what we read he could take all the info on the parts we have and put us a custom grind together to maximize our package and parts. They did go above and beyond the call of duty to work out a trade for our 3Xtra heads for a different more appropriate set of heads, set up by Scott for our needs. As part of that deal Chris also did the custom grind for us.

Since the Mutha cam had been in the engine prior, the thrust with it was 3 thousands, rearward, 7 thousands forward. With the only thing being changed was the new Straub cam we expected to get similar numbers once installed. Instead we got thrust clearance only in one direction and that's when we posted here.

Our problem now is, we evidently have asked too many dumb questions, since when the heads came from Scott all we got a list of parts installed on the new heads and not much more. We had to telephone Brodix to ID the heads and we still don't know exactly what set we have. Brodix 2xtra is all we know now.

Same deal with the cam, we got it and a cam card that had little information. To the everyday builder the card probably had what experienced people need to know, but for us that info was very limited. We didn't even have an idea what we could expect from the cam. Like the normal sales pitch a cam company would offer when you are searching for a cam we had nothing like that.

No idea what powerband rpm range was that we could expect, no idea on the particulars like what dist. gear to use, did it have 4 degree advance in the grind? (so we could install it dot to dot), what the thrust should be. We asked and got answers on the thrust and dist. gear from Chris.

Once we posted our cam numbers here on the forum though, I think we fell out of grace with the Straub guys. We thought readers would be able to say that cam should do this or that instead we got ourselves in trouble with the Straub guys...

That's the whole issue, they went out of their way to help us, we certainly didn't want to leave them with a bad taste for doing that, just so the next guy who needed help like us that they might again assist that person as well.

We've even posted so future readers would read how they'd helped us out of the trouble we had, how we thought they deserved and still do think they deserve the praise. BUT...

It's really tough though to ask for specific info and basically get as an answer "you got what you need" (in essence), and not much other information and now no response at all. So here we are, wondering what we have for cam and parts, and only the forum members to ask for advice on issues we are running into now -like the thrust issue we have right now.

57Chevy

 

Thanks again to all that have responded...

Since the Mutha cam had been in the engine prior, the thrust with it was 3 thousands, rearward, 7 thousands forward. With the only thing being changed was the new Straub cam we expected to get similar numbers once installed. Instead we got thrust clearance only in one direction and that's when we posted here.

57Chevy

Hi "57", you need to really clarify this part of your post, been doing this a very long time and for the life of me I can't wrap my head around that highlighted statement???

Unless there was NEVER a cam button in play? but I still can't fathom it??

(Add) I would also say a large percentage of ALL builds up here (generally speaking) do NOT need any "custom-grind" cams (again, my opinion). The only time we do customs is when we are absolutely "chasing HP"?

Thanks, Gary in N.Y.

P.S. Between ALL the names you mentioned up here I would have bet-the-ranch this build would have been literally a "walk-in the park"?

 

Reading thru this thread and scratching my head. From a casual on-lookers point of view, I'd recommend loading everything up and carry it to an engine builder and have it professionally assembled. Please don't take that as a personal attack, it's nothing more than friendly advice.

 

reading thru this thread and scratching my head. From a casual on-lookers point of view, i'd recommend loading everything up and carry it to an engine builder and have it professionally assembled. Please don't take that as a personal attack, it's nothing more than friendly advice.

x2!

 

Forget using those thick head gaskets, your squish will suffer terribly as well is dropping the compression. No way will the engine perform crutched like this.

Calculate the gasket thickness necessary to keep the squish, then check valve to piston clearances. If necessary to provide adequate clearance cut the valve pockets. Either build/buy a cutter or take the pistons to a machine shop to be cut.

I am surprised you haven't heard back from Chris. He does stay busy. Generally his attitude toward publishing spec's is once it's paid for it's your's to do with as you please. If you want to let the world know what the numbers are that's your business. If Chris specified the cam/heads to give you a HP then squish must be correct in order to make that number. Deviation from the script will not perform to spec.

Cam end play. I suspect that if the cam slid into the block freely there is not going to be a problem. Remove the chain and remeasure. Historically FT cams 'floated' in the block, held centered in their movement by the chain, timing suffered, hence the use of cam buttons to help stabilize timing. Advances in design to the cam retainer plate further stabilized cam walk to a close minimum further stabilizing timing.

Installing 'dot-to-dot' you may be defeating the purpose of a custom ground cam. Those few degrees off either way will make a difference in the motor performance. Looking for an excess of 800 Hp if I read correctly, you need to be sure that cam is indexed correctly.

 

Charlie,

Scott at Straub hooked us up with the correct heads for our needs, put personal time in for us on them as well.. So we are back to stock head gasket thicknesses.

On the cam numbers -they said the same about posting the numbers, that you mentioned about once paid for and that I could post if I wanted to, which I did.

BUT that's when ALL my questions stopped getting answered by both Scott and Chris. From stuff you mentioned, I think you've read some of our previous posts and now know our my health situation.

I don't understand why the numbers on the cam should be kept secret, Chris is known for doing grinds that match the whole engine and parts package. In our case we wanted not only street strip performance but also something we could use on track days. So for our numbers to be anything of a big deal, another fellow would have to have almost all the exact parts and needs we do and plan for a similar use.

We really just wanted to know what we could expect from the cam when we posted. I searched trying to find similar numbers in different offerings from other cam manufacturers to really no avail. Hence why we posted the numbers here, hoping members who knew what the cam would / could do would chime in.

Our issue now is -for example we wanted to know if the 4 degrees normally added to performance grinds was included in ours. Wrote asking about it, no answer. Looked on the net and found some info saying that supposedly you can tell by the center numbers when it is included. So based on what we read and we "think" it is, we installed it "dot to dot", but it would surely have been nice to hear from Chris that is was in there for sure.

That's the struggle, if we knew everything about cams and installing them, we wouldn't need big engine and cam guys -we'd be in the engine building business. So even our "dumb" questions should be answered we would hope. I mean I telephoned Brodix and got more information on the heads than I got from Scott (who put them together for us), than Scott told us when he shipped them our way.

Guess it boils down to most of their customers must be allot more knowledgeable than we and as such they don't have to answer the dumb questions like ours. We were tickled pink to have a custom grind done by the Straub guys so in the end -we still win -sorta!

I'd like to add just to be sure those that read this know that we are happy campers with what the Straub guys and what they did for us. None of this is intended to make anyone look bad, just venting the frustrations of us chasing answers to our basic questions that made us stop the assembly process until we know if we are good or not. Like this thrust situation. It's been a week now and we still don't know for sure if our thrust direction is OK.

57Chevy

 

Have you degreed the cam?

 

Haven't degreed in the cam as yet, no sense moving forward until we had an answer on the thrust issue. We also ordered the wrong degree wheel for our needs, since we need the kind that allows the wheel to be moved in relationship to the crank, where ours was the kind that bolted to the crank.

We've seen boo-coo vids on TV and on the net showing thrust amounts to be anywhere from 5 -15 thousands. We actually saw one just today by the engine power show where when they checked the cam thrust they only had 5 and in ONLY one direction -same as our issue! Theirs snapped back 2 thousands or so...

That's another issue degreeing in the cam -we've watched a few tutorials on degree in the cam heads off and have what we need fixture wise to put the dial indicator directly and inline with the lifter for the measurements to be taken as the tutorials show, we also made our own dead stop.

The problem we have is the cam card that came from Straub, doesn't show the same numbers and info that we see being shown in the different tutorials. For example the 50 thousands reading on the dial indicator should show us a matching number on the degree wheel from the cam card. We can't identify those numbers we see others being shown (the mutha thump cam card does show this info, allot more info the Straub one), so even after we get the new degree wheel in that won't turn when the crank does and will let us zero the wheel at true top dead center, we are not sure if we'll be able to figure out the info on the Straub card that correlates with the degree wheel numbers. .

Guys that degree engines all the time probably would easily identify the info needed from the card, while we doing it the first time, won't seem to be able to. Truth is at this point I'd just like to put it in dot to dot and be done with it. I can't believe a cam cut by Chris for our custom needs would be out of acceptable range even with other tolerances building up, their stuff is just too good.

Although tempted to not degree it in, we are going to do it the right way and have ordered the correct degree wheel and mount for our needs. Although even once we have it, we probably won't know what the numbers mean!

So right now we plan to shim the thrust button to reduce our existing thrust of 10 thousands to something more like 7 and live with it only moving forward.

Thanks for everyones time!
57Chevy

 

does the timing chain have a thrust bearing? the reason I ask is that if so they have shim kits to put behind them where the old cam spacer sits you can use those to set the lobes closer to center and then use the cam button to set the end play from there.

 

http://www.chevelles.com/forums/13-...mance/925593-straub-custom-grind-curiosity-killed-cat-syndrome.html#post9273969

Seriously, if you can't understand this cam card, you need to load the engine up and take it to someone competent. That cam card is about as easy to read as it gets. Like the above poster quoted, not being mean, just truthful. You've come this far, why not get it right. :yes:

 

"We've seen boo-coo vids on TV and on the net showing thrust amounts to be anywhere from 5 -15 thousands. We actually saw one just today by the engine power show where when they checked the cam thrust they only had 5 and in ONLY one direction -same as our issue! Theirs snapped back 2 thousands or so..."

As mentioned earlier, the cam is snapping back because the chain is on. Either that or the endplay is to tight and the timing cover is pushing the cam back. You don't have thrust if the engine is not running, you have endplay.

 

No lifters or chain when checking endplay. Cam will float free in the block and move with no resistance at all.

 

The shim goes behind the cam gear but not in between the cam and gear, this brings the cam forward in the block not rear ward. from what you had said I believed the cam to be to far back in the block.

 

Behind the cam gear but not between, like a Trrington bearing!? I'll look into it asap, a couple thin ones couldn't be much dollar wise and since we want to measure without the chain on, it'll be worth while to know what difference it makes. Just need to avoid the chain making contact with the cover. Will report back! I'm getting real good at making timing cover gaskets don'tcha know!

Thanks!
57Chevy

 

Just install the timing cover with a dry gasket, snug it down and set endplay. Once the endplay is correct, put a light smear of sealant on the gasket. No need to put a new gasket on every time.

 

Almost every issue been discussed above here about setting the cam end play doesn't apply when you use the cam thrust plate platform. Simply bolt it all together and just check it, doesn't get any easier! The timing covers play no part in cam end-play any longer.

Cam pricing is identical, MkIV and MkVI, hyd-roller or mech-roller. Timing sets likewise!

Thanks, Gary in N.Y.

P.S. We've cut our inventory in half recently with respect to stocking roller cam buttons and cam lock plates. All we need are the cam thrust plates on the BB's. I have a whole bunch of "happier" customers assembling their own roller builds now!