68GTX440

To begin with, I am not an engine mechanic. Rather, I am mechanically inclined, retired and now anxious to modify my 1968 Plymouth GTX 440/727. It has been in storage for over 25 years and driven from time to time, just to keep things in reasonable shape until I could focus on rebuilding the car. During this time frame a number of quality original (exterior and interior) parts were obtained and have since been installed. I am now working on a long list of mods under the hood and have run into a snag with the valve train. In due course, I will be swapping out the original cast iron heads, keeping in mind this ride will be nothing more than a weekend driver, while I own it anyway. I am currently installing a Whiplash cam & matching springs supplied by Hughes Engines, together with a full bag of misc. goodies from other vendors. The springs call for 1.88" Installed Height, which I have at the valve pocket, if I throw away all my current shims. I know, I must have at least 1 shim under the valve to protect the head, so I must either mill valve pocket accordingly or increase the IH using +.050 retainers. Problem is, offset retainers, properly covering new outside spring OD of 1.54" c/w a middle spring OD of 1.110 to also properly control the lateral movement of a single spring & damper, only can be found in 10 degree retainer & lock combos. The 2-4 rounded grooves on my current valves (3/8" stems), prevent my selection of 7 or 10 degree, +.050 or greater, locks, in order to work with the standard larger retainers.
Although I will have only approx 325 lbs of valve pressure @ .050, I think I have no choice but to use 10 degree retainers, usually reserved for higher pressure builds. Currently talking with K-Motion. They may have a solution. Your comments are appreciated.

Drag Pak

Mill the spring seat/head.

RacerHog

I agree... I think to get .050 your going to have to do the seat pocket. And with that make sure your check the retainer to valve guide clearance before and after the machine work...

I like K-Motion Springs, They bailed me out of a bind once-a-pone-a-time..

68GTX440

After posting my last thread asking for help, I spent another 4-5 hrs researching and exhausting all available options, before resorting to milling the heads, a quick fix and good advice, to resolve my problem, had I not spoken to Hughes Engines today. Earlier I had dismissed their 7 degree retainer #1256, thinking the OD was too small to properly cover the 1106 spring which has an OD of 1.540. What I didn't take into consideration was: their smaller retainers having an OD of 1.375 and a tapered top edge leading upward from the circumference; helps to achieve a minimum of 0.010" or better clearance number - between the retainers & the rocker arms. Not only does this retainer raise the IH by +.075", giving me the ability to shim the spring back to 1.88", but it's medium spring OD of 1.113" was confirmed to fit perfectly inside the recommended outer spring #1106, noted to have an ID of 1.113", effectively eliminating any lateral movement of the spring beneath the retainer. How good is that! I also saw that Hughes offered just one valve cup, #1372, with an ID = 1.031", which nicely clears the base of my valve guides, each having an OD = 0.980". That said, I was still concerned about the cup being compatible with the spring, as the cup's spring pad OD=1.520" but is within an overall reported part OD = 1.640". Hughes Engines fitted both parts, while I was on the phone, and confirmed the spring and cup were compatible. How good is that? Finally I have a combo of parts that allows me to install and control the spring, both top and bottom, with the cup doubling as a shim regaining 0.060" of extended 0.075" IH, bringing this build back to within a thin shim of correct numbers. If all this isn't good enough, Hughes Engines also put together a 7 degree (2-4) lock package, not listed on line, to resolve any potential issues, I might have had using my original locks. After a week of dicking around with this, I am a very happy camper to get all this stuff figured out and TY for your replies! My only worry at the moment is having enough retainer to rocker arm clearance, once everything locks down tight. Will watch that closely, swap out retainers
to standard height and mill as per your suggestions, should it come to that.

PS: I also learned - I don't have nearly enough spring pressure at 350 lbs to correctly use 10 degree retainers and locks. FYI.

RacerHog

350lbs On the seat is not enough for 10* retainers? Hummmm

Keep a good eye on the retainers and also valve tip to valve stem alignment.

And a good set of push rods....

68GTX440

Thanx Bob... hadn't thought about changing out the push rods. Probably not a bad idea to swap out the older parts for something stronger. I will look to see what is available out there, knowing nothing about push rods.

With the tight fit of this new retainer together the a lower cap that is really not necessary, I am hoping the alignment is about as stable as it can get... but for sure I will keep an eye on things.

Re My Comments About: 10 Degree Locks & Recommended Spring Pressures

It was based on a quote from Hughes Engines, as follows.
I have no idea if it's right or wrong info... Your thoughts?

7° vs. 10° locks. We do not recommend 10° locks unless you are using extremely high valve spring pressures (such as 650lbs or more open pressure). The colleting action (clamping) of 7° is much tighter than the 10°. If you should encounter valve float, 10° locks will unlock much easier than 7° locks.

Drag Pak

hmmmm is right!

What rpm do you plan on running this engine to?

What are the cam's lift spec's?

Larger pushrods probably need cylinder head clearancing also.

Better check retainer to seal/valve guide clearance.

68GTX440

This car might see a few miles on the street during the summer, that's about it. I don't expect to push things beyond 5000 rpm.. being the old fart that I am!

Installing a "Whiplash" cam supplied by Hughes Engines.

1.5 Intake & Exhaust Lifts = .518 (Nothing Outrageous)

There are a couple of good clips on YouTube, featuring the cam.

It don't see it as a good choice - if serious about winning races!

No doubt, this cam is more for show than go, which is ok for me.

According to Hughes, this is simply a bolt-in cam, so my doing anything extra to the valve train to make things stronger, is simply my wanting to do things up right.

For sure, I will keep my eye on all clearances, as I go.

Hopefully, things bolt up smoothly & looking forward to turning the key.

BTW, thank-you for your input.

Drag Pak

I believe, the springs are WAY TOO HEAVY for the rpm's desired.

Something along the range of the Mopar single spring and damper with a 1.86 - 1.87 installed hieght (Mopar recommendation of # P5249848 chrome silicon)would be way more acceptable for your situation. This spring is for a 0.480 - 0.540 lift camshaft.


Best of luck. Use VERY GOOD Break In oil!

68GTX440

Wow... I wasn't expecting to hear that my new springs are thought to be way to heavy for my street application. Now you have me thinking, I should stay with my stock valve springs, (shelf the new retainers and springs) install the cam and see how it runs... before dealing with the stronger spring and retainer upgrades.

In reaction to forum comments, I have observed that my push rods are nearly identical to Comp Cams High Energy Push Rods (Part#7840-16) which are: Non-Heat Treated; Steel; B-B welded tips; 5/16" Dia; and 9.315" Long.

After cleaning and examining my old pushrods, I noticed 2 thin wear marks or grooves, each measuring about 1/16" wide - surrounding the full circumference of the pushrod, and each about 2-1/2" up from the ball ends.

These grooves are just noticeable to the touch. I have no idea what they were rubbing against to cause this damage and have no idea how much of an impact they have on the pushrod strength, so will order new ones.

So the world turns... Good grief.

68GTX440

INDEED... I am up to speed on the quality of recent oils and have decided to go with JP's initial break-in oil and afterwards, run his normal product line - in the old flat tappet build.

68GTX440

After my morning coffee, I will clean and inspect all my old push rods to see if there is (similar or other) damage elsewhere while checking em all for straight. Not exactly what I had in mind to do today, but one has gotta deal with what comes your way...:banghead:

Coronet 500

First I don't understand 325lbs@.050. Most engine rebuilding shops I have talked to will test one or two valve springs, no charge. If you want a bunch tested and documented at seat and lift heights then they will charge you.

68GTX440

Just going by Hughes Engines specs on their #1106 springs.
With an installed height of 1.88", they give you 125 lbs. pressure with all valves closed and 325 lbs. on all your valves when .050" open. That's about all I know about these valves for now. As my lift is slightly higher, I should expect a little more pressure than this, when fully open.

68GTX440

Well, I completed an initial check of my push rods. The good news is, they are not all bent or scored. The bad news is #s: 1E;2I;4E & 8E are scored & bent.
Bent only to the extent, you can see a sliver of light appear and disappear along the middle of the push rods, when rolling them across glass. #8E has two score marks, unlike the others only having one. I suspect who ever did the last build, inserted the #8E push rod upside down, creating the second mark, as nothing in the block would contact the push rod at this location. I did discover, there is a ragged casting line, situated approx. 2.5 cm. down from the valley pan side of the upper horizontal edge of the heads, which runs the full inner length of the heads. This appears to be the culprit and I will be grinding that crap off before reinstalling the new push rods.

68GTX440

Oops... Where ever I have stated a lift of 0.050", it should have read 0.500".
Sorry for the confusion.

Coronet 500

I thought so. Sounds like you've got it figured out and are not overlooking anything. I would seriously consider the Magnum pushrods as they are Chromemoly, a little stronger and lighter and good piece of mind.

My thinking is stock cam and valve springs, stock rod ie. High Energy.
Bigger cam, bigger springs, stronger than stock rod needed ie. Magnum.

68GTX440

I did look at the magnum pushrods, thinking stronger is better, but didn't see any with B-B tips. Will look again. Thanx muchly for your comments. Gotta put an order in by tomorrow morning for push rods, so better get this figured out pretty quick - one way or the other.

Coronet 500

Non of the chromemoly show a B,H or I welded tip.

68GTX440

Ya. Comp Cam doesn't show a product I need. Sent a message off to Crower with push rod specs to see what they can do for me. Meanwhile, I've found Chrome Molys in the right length and with B-B tips on eBay. Can you believe that? Not sure if they are junk, so will wait to see what Crower says, before proceeding with this. BTW... anyone know the end radius on a stock BB pushrod? I am guessing 5/32" vs 3/16" but not sure...

RacerHog

Here you go....
http://www.mantonpushrods.com/
Or
http://www.pushrods.net/

68GTX440

Wow. Thanx Bob! A truckload of awesome-to-outrageous push rod info there to digest. Will try to put it to good use.

68GTX440

I ran my build by Al at Manton earlier today and he took the pain out of selecting all the correct materials and ends in combination with needed measurements to fabricate set of high quality pushrods to suit my build.

Al was extremely helpful and recommended that I check the pre-load on
at least one of my new lifters - using an original rod and dial gauge, prior
to confirming the order. Despite the supplier stating that I was getting a
bolt in cam and didn't need to change anything else in the valve train...
often times a new cam of this duration, requires push rods of a different
length, to ensure that a proper pre-load on the lifters is established.

I temporarily installed the new cam using light weight motor oil - for the
test tomorrow morning only, and am currently soaking a new lifter within
Break In oil overnight.

Tonight, I measured a new hydraulic lifter's length and it is 0.050" longer
than the original lifters. I will use a dial gauge in the morning and compare the standing heights of the cups when loaded with oil. From what i am seeing so far, there is a good chance, my push rod length will have to be adjusted for the new lifters, not to mention the cam. Good grief.

Thanx Bob for pointed me to Manton. Without Al's advice, this build would have gone wrong in short order using the original rod length. I have learned,
it pays to double check & confirm your numbers - assuming nothing.

RacerHog

No Problem..Glad I could help you in the rite direction...Kinda seen it coming. I'm sorry to say. But this part is very important... Make sure you get this part rite... And You keep the rod demonstrations in case you need the info down the road or at a later date....
So Far the rest I can live with....lol

68GTX440

Well, it's been a long day. Started out by wrenching my back while attempting to rotate the 440 block on a lousy engine stand. Popped a few painkillers and carried on with this, must get done today, valve train assembly, targeting #8 Intake and Exhaust push rods. I measured pre loads on the new hydraulic lifters having temporarily installed the new whiplash cam for this purpose, prior to the confirmation of my new push rod order & upon the recommendation of Manton.

It was a good thing I spend the time doing it! Turns out, my existing pre-loads are a touch high at .050"-.055", having just snugged down the head & rocker shaft for this test. Once torqued to specs, Al @ Manton, had suggested that I can expect to see pre loads of .060" - .065" using my stock push rod length of 9.315", so my order for new push rods was adjusted accordingly.

All in all, a good days work for this old fart. Now, it's time for whiskey.

Coronet 500

You might want to order one or two extra if they are custom order. If you did bend one years from now you may have a long wait to get another, hope for the best prepare for the worst.

68GTX440

For sure a good idea, if I was entertaining the idea of ever opening up this Pandora's Box again. Should things ever crap out in this valve train again...
I will seriously entertain a new kind of crazy under the hood.