Inliners International Forums General Discussion Engines 235/261 Valve Springs

Having read through the posts that I could find on valve springs, the TRW VS1020 was the most mentioned. TRW no longer exists and I can find no cross. I want a spring that fits the head without any machine work and will handle 6000 RPM on a roller or solid lifter cam. I tried going through the PAC catalog but ended up even more confused. The Buick 455 spring seems to be favored, does anyone have a part number for a spring that meet these criteria.

Thank you

Warren Grimm

TRW is now a subsidiary of ZF. Try that information in your search engine. They are still in business. They have several plants and facilities in my area!!!

A roller cam requires almost double the spring pressure of a flat tappet style camshaft, so finding one for that application that doesn't require machine work may not be possible.

That TRW is much stronger than the original springs @ 373 lbs. (vs. 307 and 318) per inch deflection.
Competition Cams #910 is even stronger at 415 lbs./inch:
OD 1.354", ID .940", assembled @ 1.45" gives 92 lbs. closed, 279 lbs. open to .450" lift
There is a wide range of 1-1/4" OD dual springs (doesn't fit the head directly but requires a spring cup) including Crane 99848, Crower 68301-3, Crower 68301-1, Comp. Cams 981.
The highest safe pressure on a flat tappet cam is fairly modest, anything above 280 lbs. is at risk.
Any roller is billet and able to withstand much higher pressure but, as said, needs much higher spring pressure (the tappets are heavy and the action violent). Bigger springs are available but may need the seating area on the head machined, guide cut down, etc. but the rest of the valve gear (rockers, stands) aren't that strong.
Are you sure a roller is necessary?

Unless you're using very hot cam timing (250° @ .050" etc.) and a professionally ported head you won't have any power at 6,000. With given set of parameters (reciprocating valve train mass, lobe acceleration rate) 6,000 RPM requires about 44% more open spring tension vs. 5,000, that's really high.
More information about the build, please?

I bought a McGurk roller cam assembly from Cory Beck here on Inliners about 4 years ago. It included the cam, the lifters and the springs. I ran it last year but snapped a damper and bent a push rod at about 5600 RPM. Since I run nostalgia, I feel this is a significant piece to have. I was led to believe that the Buick 455 sping fits the pocket. I see that TA performance makes a roller cam for the 455. I will check with them when they open on Monday what spring they use. The head is in the machine shop right now and I could turn the guide and/or change the seat. I wasn't aware of the need for a higher rate spring for the roller cam, I don't think McGurk was either. I could use a dual spring, just don't want float. Still open to any suggestion.

Further, I am aware that my best power is probably in the 4800 range, but I don't want float and since I am changing intake, headers and head work, I want to give myself a little room.

Thanks

Warren

If you had some cam data for the roller, you might cross-check other modern manufacturers for comparable RPM vs. open spring pressure. Are there part numbers on the cam? Lobe height?
Is the failed pushrod definitely a match for the cup radius in the roller tappet (which may not be stock for that year stovebolt)? I would certainly get the best pushrods, Smith, Manton etc. can supply a 3/8" tapered pushrod that will clear your block and head with a bit of work.
I assume you have stock latest rocker arms (raised fin across the center span)? Some weight can be safely removed from them by hand, not critical but every little bit helps.

I have the cam data, it came with the cam. The cam had never been installed. The push rods were part of the package. They were unlike stock push rods. Smith Bros. have just made me a new set using an original as a pattern.The rocker arms are stock 1961. I will talk to PAC and TA performance on Monday.

Warren

I just ordered valve springs and retainers from TA performance. These are for a Buick V6.

Original Specs TA specs VTA1435
1.3125 spring diameter 1.360
1.8125 intalled height 1.860
115 lb valve closed 100 lb
315 lb valve @ .500 315 lb

both springs have an inner damper
retainers are correct dimensions

Considering the input I have received, I think I have made the right decision.

Thanks
Warren

The spring pressure you listed is about 1/2 of what is required for both the seat pressure and open pressure for a roller cam. The Buick springs that keep being mentioned as upgrades are for flat tappet cam use, not roller cam. Also, stock rockers will not survive long with a roller cams spring pressure, and you can also break the rocker shafts and pedestals too. Stock replacement valves will also snap the heads off if not upgraded to race quality material, along with machined retainers and locks instead of the stock stamped retainers and locks. Are you sure about your numbers?

The specs on the original are what came with the cam from McGurk. I son't want to go too much higher on the spring rate with these rocker shafts. McGurk talks of using this cam with stock rockers and not to use 1.6 Barker or similar type rockers. I will go with his recommendations and see when she blows up. I appreciate the input but can find no alternative out there.

Thanks
Warren

Does anyone know the weight of a non roller lifter?

Warren

In my experience with the stovebolts - the construction of these pieces can vary quite a bit between the OEM and aftermarket offerings with concomitant variability in weight.
Inliners Posting circa '15
Best to weigh what you actually have in hand or can obtain.



My circa '06 Clevite interchange lists two cross-references for that TRW part number:
212-1134 and 212-1263.

I think I see what you're trying to do - estimate the extra weight of the roller valve train and adjust spring tension to suit: 15% more weight needs 15% mote spring tension, etc.
It's far more difficult than that, the mass of the reciprocating segment of the spring (not all of it) is included, as is the reciprocating mass of both ends of the rocker arm. If that's not enough, you need Cam Doctor to analyze the lobe shapes of your roller vs. a lobe with a known spring recco for acceleration and velocity.