Well you wouldn't f****n read about it.


I paid up front for my engine work, was told would be ready in a week.
2 months later still not ready, and to add insult to injury they have rung me and told me that my engine has flat cam lifters!
I know that's not true as I took the lifters out myself!


It seems they've had my stuff sitting around for so long they've misplaced my lifters or are looking at someone elses.


I'm not very happy but cant do much at this point until they get back to me and /or acknowledge they have made a stuff up.


So, that's the news and weather from NZ


Sorry about the rant


Later

 

I certainly hope it's not a case of out and out fraud.
When I had my last shortblock done, (Fall 2012) , I told my builder to take his time. Well, THAT was a mistake. It took two months and a half dozen phone calls to get the project finished. That said, the results were (and have been) excellent. I had dealt with the same builder for a few decades but the ownership has passed from father to son so the dynamics are a little different.
Good luck.

 

I arranged to meet him today, took a couple of hours off work and when I got there he was out.

I spat the dummy.

His boss (unluckily for him), walked in at that moment and copped a 10 min earful. I told him what I thought of his business called them a bunch of clowns plus a whole lot more! He walked out a very chastined man.

When the mechanic finally got there we worked out what had happened. Apparently one of the staff had put a set of flat tappet lifters on top of my box of stuff and my mechanic thought it was mine. After chewing his ear a bit we found my lifters in the box.

So now the engine is almost finished (reassembled) and I am meeting them Friday to do the valve geometry/pushrod measurements.

I'll be glad when it's over. It's been a frustrating process dealing with them.

All good though ,I got over it lol.

 

I'm interested to hear their approach to that and what they come up with.

 

He wanted to do the mid lift method so the least area of valve was run on but I think he misunderstood the approach in that article I wanted to use. We came up with 7.25 " pushrods but it was rushed and I'm not entirely happy that it was accurate so will redo it once I get it home and won't be paying 70/hr for the mechanics time

 

Taking your time is the best approach.
The very best results are with a solid lifter that matches the same specs as your hydraulic lifter (seat height is critical) and that'll alow you to use the running spring that'll be on the head. That way the tolerances are taken up. An alternative is to use a generic "checking" spring from the hardware store. Something with enough heft to keep the valve closed but no so much as to collapse the hydraulics. If you recall in Jim Miller's article, that's somewhat less precise however he's building engines to the nth degree. Me...not so much. I just want my guides to live.

 

Yeah, Jim Miller said as much as .040" out.
I don't have access to a solid lifter but can probably shim up one of my hydraulics. Trouble is the comp pushrod checker can't handle being used with the proper valve springs so I'm going to use the static method from the article which is done with valve closed. I know from last weekends effort that 1/2 lift is .272" so can work out the rest based on measurements.
Hopefully it will be close to what we already worked out (7.25")

 

I'll have to re-read that article as I don't recall the static method you mention. My question about that method though (judging by it's name); is there an imprint left on the valve tip so the contact patch can be verified. The rocker sweep across the valve tip, when it's at it's narrowest, verifies the correct pushrod length. Getting it close to centre is another issue and one which brings about some interesting debate.
Like I said, I'll have to go that paper again and refresh my memory. I had thought I'd have my own heads pulled off at this time and would address my VGT again however I've decided to let things remain as they are for the balance of the season, race the crap out of the heap and hope I don't blow something up. I know the guides are worn from my previous tear down but I didn't follow through with another guide replacement as I wanted to get the thing together. As it is, I'm going through about a litre of oil for every 2000 kms depending on the driving style.
At any rate, let us know how you make out.

 

Well...?

 

Sorry a bit slack keeping updates.

I originally measured wrong (my fault) and realised when I re-read the article.

I had originally calculated the push rod length based on trunnion centre to roller centre which was wrong. We came to a 7.25" length. Upon measuring correctly it was in fact 7.4" needed. I checked the difference (which would have to be 1/2 the roller diameter) and that worked out.

My 7.4" rods have just arrived in NZ so I will receive them in the next day or so.

One worrying thing, the difference in rod length along the length of the engine was nearly .020". This points to the block or heads being machined or cast inaccurately. Not sure what to make of that.

Anyways just to make my life complete my car failed it's inspection due to chassis cracks around the steering box. I have removed the engine and started cleaning up unwanted wiring and gotten rid of air con and heater and some slight alterations required to fit the 3 row alloy radiator and when that's done the car is going into the panel shop for repairs and underhood repaint.

I will start final engine assembly next weekend and then wait until I get the car back for engine install. Still heaps to do with fuel pumps exhaust etc so will be a little while before I get it back on the road.

 

That link to the article no longer works. Luckily I had a paper copy available.

I'm going g to have to wait to confirm rocker sweep to I have my pushrods as the comp pushrod checker can't be used with proper valve springs and the article says don't use a checker spring because the result could be as much as .040" out.
At least oil is cheap. My 305 is a smokey old thing too but surprisingly uses very little oil.

 

http://www.engineprofessional.com/do...2010_20-30.pdf

That link works for me.
Anyway, the 7.4" length seems to be the "go to" standard for your application. Never having had an OEM roller block, I've used retro-rollers and the length is more like 7.2" (I think). I can't recall, at this moment, what I've got for a pushrod but I will restate that I had to go to an offset rocker trunnion to get the contact patch centred on the valve stem. As I approached the optimal pushrod length, the patch moved further away from the valve centre and eventually worked it's way off the valve towards the exhasut side. Again, to repeat myself, while the smallest area of contact, which ensures maximum transfer of cam information with minimal frictional forces, is the target, getting it in the middle of the valve is another task altogether and one which has differing opinons on how important that is. My background in physics, although not the most intense, (as I did study to be a mechanical egineer in my youth) tells me that the valve guide wear will be reduced if the force acting on them is more on the centreline than anything else.
As for the cracks in the frame adjacent to the steering box, this was an issue addressed by GM with the incorporation the "wonder bar" or chassis brace. The frame fatigue was pronounced with the wider tires supplied on the Z28 and similarly equipped vehicles. If I recall, the Berlinetta wasn't provided with such a brace. It's an aftermarket mainstay now (in case you weren't aware).
Good to see your still at and haven't forsaken the little f-body for your sleek and shiny Corvette.

 

Lol I love the vette mate but the camaro has this little bit.of mongrel that I find quite attractive in a car.

Even though the camaro has papers for 1983 berlinetta I have been told by the previous owner that under the berlinetta body kit it is in fact a 1986 z28. It has the factory wonder bar and chassis braces as well as the heavy sway bars that the z28's had so I tend to believe it.

By the way, where would I get an offset trunnion for the pro magnum rockers if required?

 

From the factory with the wonder bar AND chassis cracks at the steering box? That raises some concern for me. My impression is that the bar prevented the cracks. Something I'll have to look into.
As for the offset trunnion, my research into it returned no option for the pro magnums (that was about 2 years ago). In fact the only offset trunnion rocker I came across was the Crower and that's only available as a complete, and expensive, assembly.
http://www.crower.com/media/pdf/2008b/153-155.pdf
They're the Enduro Centerline Rollerized Rockers.
http://www.summitracing.com/int/sear...yword=73692-16
My RHS heads were fitted with a .100" longer valve which more less mandated the offset rocker. Your stock Vortecs shouldn't have that problem. When I put my Vortec headed engine together the 1st time, the pro magnums worked just fine. Those guides lasted forever.

 

It seems so. I am only going by what the previous owner told me. Apparently the donor berlinetta failed it's compliancing check here in NZ due to chassis cracks so the PO brought a stripped out z28 and threw all the berlinetta parts in it including Vin plates etc. If there is some way I can confirm the year and model without relying on numbers I'll be keen to hear it.

 

That I can't help you with as I'd be going of the VIN in the windshield.
There may be a few individualities with the Berlinetta that someone here could probably help you identify.

 

Check for vin # stickers as well. These cars have the VIN all over them.

Metal tag in dash, windshield.
Driver door sticker
Front Pass side fender, has a sticker/decal on the inside part of it. Have to remove fender to see it.
Sticker...Rear pass side 1/4 panel, on inside of car, behind all the trim and panels, and half way under the metal bracing.
Sticker...Bottom of hatch, close to the latch striker, under the plastic trim

 

Sweet, thanks night rider

 

Your welcome Loopy

 

Sorry , new here and very lost . Can someone please help me on how to post something to get help , all I want is a cam and head combo crane 2032 cam and edelbroc 60859 heads for my tpi 350 auto ..I just don't know what rods springs lifters and everything else I need to combine these parts together and run smog legal . I really apologize for the interruption I just made in this room

 

HI. Welcome to 3rd Gen. There's a heap of very knowledgeable people here.

I would start a new thread in the engine forum. There should be a button at the top of the list of threads that says "new thread".

Here's a link https://www.thirdgen.org/forums/tech-general-engine/
Just hit on that box at the top left of the list of threads and ask your question

 

And that's how it works.

 

Well I got the beastie pretty much assembled today. A few hiccups, tools I didn't have etc













I put this photo in Kevin, even though it means bugger all, due to using hydraulic lifters without packing the lifter,
so isn't really representative of width of running mark on valve tip.
Still, it gives an idea where the rocker tip will run. This mark is a full revolution of cam, as I said, with out having the lifter packed solid

 

I'm confused. Is that mark with or without the lifter packed? The reason I'm asking is because once you add the .050" (or so) of the lifter hydraulics, you'll really start to push that contact to the edge of the valve.
I will say that the mark is about as narrow as I've ever produced so the length appears to be good.
And having said that, the Vortec guides are extremely durable and I doubt very much that you'll have any trouble provided the rocker doesn't ride off the valve tip .

 

Nice valve covers.

 

Sorry mate I didn't notice that.

It's without the lifter packed.

From looking as I was turning it over I think that is as far as it will travel outwards, all the remaining travel is inwards toward the valve tip centre.

I will definitely recheck once I have a priming tool and can get some oil pressure up to check it properly.

I have edited my post. Sorry about that

 

Are they the same as yours?

It was not intentional

You must have good taste lol

 

I'd be very interested to see the before and after results. You should be able to keep the priming tool engaged and the oil pressurized while you do the sweep test.

Yes. The same. Mine are Proform. They're licenced to produce the Chevrolet brand.
I had a few problems though.
First, mine were prone to leaking at the back. The bolts supplied by Proform bottomed out in the head before the covers were tight. I had to modify a full set of my own fasteners so I could get a torque value before contact. Even so, they still leaked. I solved that problem by gluing some blue silicone gaskets to the covers using Permatex Right Stuff gasket maker. The bolt problem I doubt you'll experience as yours is a package right from GM. Mine is an aftermarket collection of parts. I can't say if you'll have any trouble with leaks. If you do, that rememdy should help.
Second, I had contact against the rocker body and the extreme top corners of the covers (2 locations per side). You may or may not have the same trouble with your Pro Magnum rockers. There's a shoulder built into the cover that I had to grind away for clearance. If you get a steady tapping despite having the lash adjusted properly, that could be the problem. The black powder coat gets worn away over time and the contact is obvious.

Looking good.

 

I'm pretty sure mine are proform too.

They were definitely a licensed product.

I was going to use fabricated alloy covers but wanted the chev logo so these were the best available.

I'll keep an eye on the tapping thing.

The keeping the oil pressure up while cycling the rockers was my thought on the best way to check the rockers as I had no way nor knowledge to pack the lifter on hand

 

HI , how do I remove myself from this post and to stop getting emails

 

I hadn't thought of using the primer to build oil pressure. I've always performed the test with either a checking spring or relied on the residual oil pressure (testing done on a functional engine) to keep the lifter as pumped as possible. I may change my approach.

 

There are a couple of ways.
There's a link in the e-mail you recieve that will allow you to unsubscribe. Click and it and follow the instructions.
Alternatively, you can go to your user control panel, select "list subscriptions", check off the thread you wish to unsubscribe from, scroll down the page to the drop box, open it, select "delete subscription" and you're done.

 

Hey Geoff.
Would you mind running through your engine specs again?
Piston below deck value, piston dish volume...I think I have the rest. XR276HR cam, 1.6 ratio rockers, Victor Reinz .026 x 4.100 head gasket, Vortec heads ( not sure of the actual measured chamber volume). Im going to run a simulation and also try and guess what your actual cranking compression is going to be. (This means doing a compression test after the engine is broken is which of course is up to you).
If your ignition, induction and exhaust are reasonable, consensus is in and around the 375-400 hp mark (at sea level with good density altitude).

 

Ok,


I have copied and pasted our specs from earlier in the thread. Bear in mind the measurements were for the Fel-pro 0.015" shim Gasket.



Bore: 4.00
Stroke: 3.48
Chamber volume: 63cc
Gasket: .015" x 4.100" (FelPro)
Piston to deck clearence. 0.00"
Piston dish. 21cc
DCR with the 270: 7.58:1
DCR with the 276: 7.42:1


Piston dish in the above calculation included deck volume of 0.025"x4.00"


I think from memory, actual dish volume was 12cc.




____________________________________________________________


The current setup is:


My machinist measured chamber volume at 62cc.( I got 63 and 64cc)
Dish 12cc
Piston below Deck height 0.014" (this to allow for the .026" gasket while maintaining 0.040" piston to head).


All else as you listed.


Induction is RPM Airgap manifold, QF HR680vs Carby and CAI.
Mr Gasket electric fuel pump 95gph to QF bypass regulator.
Ignition MSD Streetfire HEI dist with Vac advance.
Hedman 1 7/8" shorties.


Exhaust is still undecided. I want the best I can afford. My son is an engineer so can get stainless tubing and mandrel bends through him, but need to research size and tuning based on the above specs.
I prefer at least 3" minimum single pipe to muffler with dual outlets and quality of sound is also important to me. Will be soliciting advice on that too


Cheers


Geoff

 

Just wondering if you re-calc'd the engine yet Kevin?


Just keen to see the result


cheers

 

I hadn't until now.
Here are the SCR and DCR calculations.
You should be able to see what I used for piston/deck heights, gaskets, etc.
I'll include the previous interations of my engine that used Vortec heads and a 276 cam.
One thing to keep in mind is how important the exhaust system is. With the shortie headers, a y-pipe and a single muffler in the OEM location, the limitation cripples the power output potential. I experienced that first hand.

 

I hadn't until now.
Here are the SCR and DCR calculations.
You should be able to see what I used for piston/deck heights, gaskets, etc.
I'll include the previous interations of my engine that used Vortec heads and a 276 cam.
One thing to keep in mind is how important the exhaust system is. With the shortie headers, a y-pipe and a single muffler in the OEM location, the limitation cripples the power output potential. I experienced that first hand.

 

I'll try and put together some dyno simulations but that'll have to wait a while. I'm heading out of town....

 

Awesome, thanks


Just a quick note about the above results,


Piston to head is .040"
.014" Deck height
.026" Gasket
62cc heads


I just downloaded the calculator so will re rum the numbers there.


I'm really keen to find out how to mitigate the exhaust induced power losses

 

Based on that information:

 

As for the exhaust, well, we're stuck between a rock and hard place.
There's not a lot of room under these cars to build a true dual system however it has been done.
What is trying to be achieved though is to have the correct length of header primary, secondary and exhaust pipe with a suitably sized muffler. Not an easy task unless you're at stock height (or more) and can live with a pair of mufflers that hang under the chassis in or around where they would be on a more typical "muscle car". Just about under the rear passenger seats.
With the short headers you have, while some will argue, you've already compromised on the best header primary length. The y-pipe further adds to the problem as the run of the mill selection is poorly designed with a significant restriction at the junction.
All of that said, dyno simulations show a significant power loss between an open header and one with a full exhaust. An engine that should produce a paper spec of 400 hp, might manage 350 at best. My experience at the dragstrip supports that result. I have a single muffler in the OEM location and it probably flows 300 cfm. With a simple cut out placed at the turn in front of the muffler, I added a couple of MPH to my 1/8 mile pass and better than a 1/10 reduction in ET.
My plans for the next generation of exhaust will keep the same single 3" over the axle however I'll place cutouts and a suitable length on my mid length secondaries. This is to try and simulate an open header, with the proper tuned length, and benefit from the resulting pressure wave tuning and increased exhaust scavenging. Admittedly, with the small amount of overlap my cam has, there's less to be gained than if I had a more race orientated profile. However, it will most certainly be an improvment on what I've got. Just as importantly to me is that it will keep all of it's streetability. I barely scrape going over certain speed bumps and the occasional nasty driveway entrance but other than that, it's very livable despite being very low and having my headers extension/y-pipe below my transmisssion crossmember.

 

I know shorties will have the effect of moving torque range higher in the revs, but am wondering what can be done further back to minimise these losses.


For example, you say the Y pipe is a choke point so rather than use a generic Y pipe, shouldn't I make a custom 2 into 1 join similar to the join in a tri Y header. Heres a pic of what I mean





This isn't exactly the design I am talking about but illustrates my thinking about joining the 2 pipes in such a way as to minimise the losses of the usual Y pipes. Imagine the 2 secondary pipes entering the flattened portion and exiting the round. This join can be made in the area best suited to make the desired pulse length of the pipe (in my case hopefully long enough to help with torque band).


I have been doing some research and Edelbrock, back in the day, experimented with an Inlet/Exhaust design that used a different length intake runner and exhaust length for each bank to achieve a wider torque band tuning. In my case that would mean the LH secondary ( I am assuming that even though primary length cant be changed there would be some advantage to a longer secondary)would extend under the auto to meet the right hand secondary thereby giving a difference in overall length between the 2 which if done properly would give a wider flatter torque band. What are your thoughts?


That David Vizard book has a section about exhaust. I will have to get it back from the guy I loaned it to and study up on it a bit more.

 

That's pretty good isn't it based on the lower octane fuel I will be using. Its right in the middle of the 7.5-8.5 range recommended

 

I would think anything you can do would be an improvment over a generic Y-pipe. You'll find that space is the limiting factor though. You should check out Dyno Don's offerings. He has pretty solid reputation here and you might get some ideas looking at how he's gone about the short header/y-pipe arrangement.
Personally , I believe in balance and working to get all the cylinders as even as possible. Now I know that's next to impossible given what we're working with however that's my thinking. That said, consider that what we buy as headers are far from "equal length". There's your torque band being moved about cylinder to cylinder anyway. There's a benefit to that too and Vizard comments on just that.
I think it's hard to define secondary length when we're building a full exhaust. In my case I couldn't say for certain where the collector ends as the y-pipe I've built extends them all the way to the merge. Now if I put the cutouts in there, as I've mentioned, then that determines my secondary.
As for your compression ratio, that DCR number is pretty good. I'll bet you'll build some fine cylinder pressure and low engine speed torque. Your fuel is mystery to me and I can't say how you'll fare. Getting the timing right will be critical regardless.

 

Some dyno simulations:
The 1st is with small tube headers and mufflers. The 2nd is with large tube open headers. It gives you an idea of what happens.

 

That seems quite the difference.

I'm going to mull this over and do some research and hopefully come back and bounce some ideas off you.

I'm thinking with the full exhaust that the horsepower loss is of less importance than the loss of TQ.
The trick here then, bearing in mind that I will generally be tooling around at 2300rpm open road speeds most of the time, will be to maximise TQ even at the expense of top end power. That will mean exhaust tuning for 2000-4000 rpm peak numbers if at all possible. David vizard said that an expansion box is seen by the exhaust as an open area therefore sending the return pulse as if at a cutout. The trick then would be to have this expansion area at the correct length for my target open road rpm range.

If/when I race cutouts will bring out the best power provided they are sited correctly.

Lots to think about here mate.....

 

Here's a picture of what Dyno Don has to offer. The dual cats notwithstanding, two things stand out to me. No bottleneck at the merge (good) and really unequal collector extensions (good/bad/maybe?). What I don't know is how those unequal lengths impact the rpm at which the pressure pulses arrive at the exhaust valve. Because the point at which the two pipes merge is not the open atmosphere (or a representation of such as in a termination box), is there any reflected pulse returning up the pipe and any tuning to be had by altering that length? I doubt it but I can't say for sure.
The same might be said for a dual exhaust system with cutouts. Even with the cutouts open, the rest of the exhaust system is still in play. Does the exhaust pulse see the cutout as a significant change in displacement or does the exhaust pipe attached to it nulify the effect?
At any rate, Don's y-pipe will certainly eliminate any restriction in the exhaust flow (as would be the case otherwise using one the crappy aftermarket pipes). Combine that with a high flow muffler (along the lines of 2.2 cfm/hp produced but good luck with that in a single muffler) and at cruise, at the very least, you'll have a healthy arrangment.
Maximum power production is another story.

 

My thoughts on this (pure supposition) are that provided the secondarys are within the parameters required the unequal lengths would provide a wider torque albeit lower average numbers than if equal length. I guess to play safe they would need to be engineered so that the lengths are at the correct distance ie the 2nd or third (etc) harmonic.



From the small amount I have read from Davis Vizard I had the impression That any
point where the exhaust becomes less restricted it sees it as open air therefore returning a pulse from that point. Again supposition......



Can I take it from that, that there are no mufflers currently available for street use, with flow figures published, to choose from?





I would have thought that calculation to be the simplest of all the above tasks (pipemax or similar) lol


I can see I have some reading to do, maybe a book or software to buy to help me fully come to grips with this.

 

I know that principal applies to the primaries. That subject is touched upon by Vizard when he discusses "equal length" headers. I can imagine that it also applies to the secondaries but to a lesser degree. Especially if a complete exhaust is attached.

I believe it has to be significant change in volume to have any effect. 8 times the volume of one cylinder I think is the spec. One train of thought is to hang a couple of empty muffler cases off the end of the collector extensions. In the case of short headers, like yours, an empty case 3 x 12 x 10 in place of the merge, would probably do it. Sort of where the catalytic converter would be.


There are a couple of single mufflers that are rated for 800+ cfm. Borla makes one that I know off. And I can imagine how loud that thing is! I think Magnaflow also has an offering.

It just so happens I have the PipeMax program...

The research never stops.

 

Dynomax lists CFM flow on their mufflers.

I run their ultra flow welded mufflers which IIRC had a stated flow rate of like 1200 cfm each or something close to that.

The are are quieter than my 2 chamber flowmaster's that I replaced with the dynomax.

In fact I went from shorty headers, dual 2.25" pipes, flowmaster 2 chamber mufflers to..
Long tube headers, Dual 3" pipes, X pipe, dynomax ultra flow welded and it was like 15 DB quieter than my old setup