Which springs for hks 272 cams?

[athlete3344]

Thread title pretty much says it all.

Im in the process of porting and polishing my head, and I found I need to get a valve job done (rough seats). Figured the stock springs should probably be replaced in the process (and retainers?).

Just need some recommendations on springs and retainers if necessary to support these cams.

Thanks,

 

[boost97gst]

Bogussvo is a fan of BC springs/retainers. I have them in mine and have had zero problems. I run Crower 272s. Very similar to HKS 272s.
You dont need dual springs but it also cant hurt. Think about that when pricing everything. It depends how high you plan to rev.

 

[athlete3344]

Yea I came across a post of his recommending I think the BC1100 springs or something - cant remember the number. But I like to find a few more references before making a decision Im not completely sure about.

 

[lasthope05]

It all depends on how high you want to rev and if you plan on upgrading to larger cams in the future. 9k and hks 272s is no problem but if you plan on more aggressive cams like kelfords/gsc in the future with the same/higher rev limit you'll need a beehive spring like gsc/kiggly.

 

[athlete3344]

Well, the head came with the HKS 272s and I dont plan on building a monster out of this car. I dont think I will rev higher than 8/9k tops.

 

[crimsondragon]

People have run stock springs with them before with no issues. A cheap upgrade would be to get stock Evo springs and retainers. That's what I run with my DKS272s and I rev it out constantly.

 

[athlete3344]

Do you happen to have a link for evo springs? I want to make sure Im looking at the right set.

 

[1G Eclipse94928]

Do you happen to have a link for evo springs? I want to make sure Im looking at the right set.

that wouldn't be enough for 9k rpm imo...

 

[miliman13]

+1 on bc springs.

 

[miliman13]

Bogussvo is a fan of BC springs/retainers. I have them in mine and have had zero problems. I run Crower 272s. Very similar to HKS 272s.
You dont need dual springs but it also cant hurt. Think about that when pricing everything. It depends how high you plan to rev.

I run this exact setup.

 

[boost97gst]

Just my personal opinion? I wouldnt rev to 9k on less than a good dual spring/beehive. Im sure you CAN and im sure there are people that DO, but the what-ifs out weigh the fun at that point. Constantly bein nervous a valve is gonna float..... uh uhhhhh, id cap it around 8k maybe 8250 with those single springs.

With that said, I have revved to 8500 before on my setup. But I was choking out up top, so there wasnt a whole lot of incentive to go that high hardly ever. Plus i never 1/4 miled the car.

 

[athlete3344]

Then I think Ill go with the BCs and retainers and just watch my revs. This really will just be a fun car. Thanks for the help all!

 

[JacksonAuto]

Evo springs aren't an upgrade.
BC100 are a good, budget upgrade for rebuilds and mild cams.
Kiggley springs are great for larger cams, higher RPM and up to 25psi or so.
Manley duals are for even larger cams and high boost.

 

[RvlutionMtrsprt]

Why do you say that Kiggly springs are only good to 25psi?

 

[pneumo]

Kiggly has two types of beehive springs available. I've been using the Race version with Kelford 272's and over 40 psi for a few years without any sign of trouble. Kiggly's Street beehive is a little softer than their Race spring.

 

[lasthope05]

They are the same spring. The only differences are the retainers and the install height, with the race being shimmed for more seat pressure.

But, I too am interested in JAM's reasoning.

 

[JacksonAuto]

Because the incoming boost pressure reduces the effective spring pressure on the intake valves. Multiply the area of the valve times the amount of boost then subtract that number from your seat pressure. Now you've got very little spring pressure left to control the valve. Remember the intake runner is always pressurized and the spring is responsible for overcoming that pressure.

A=1.441"
1.441 x 25psi= 36.025
110lbs - 36 = 74

So under boost you have an effective 74lbs of seat pressure. Not enough.

 

[RvlutionMtrsprt]

Direct from Kiggly's website:
Valve Float vs Boost -at very high boost levels, more seat pressure is required due to mistimed pressure pulses bouncing back off the valves and potentially popping them open. This is highly dependent on each combination and setups that breathe poorly seem to have worse problems. In general, about 95lbs on the seat seems to be good for about 45-50psi worst-case. If you're going to be running more than this, you may need more seat pressure. I have seen other similar engines that breathe very well work fine with 45-50lbs on the seat for 40psi boost, so it is highly dependent on the engine's pulse action and header/exhaust tuning. The steel street springs are about 85lbs on the seat and the titanium high pressure beehives are about 97lbs on the seat. If you plan to go past 40psi for the steel streets or 50psi for the high pressure beehives, you may want to add some shims. In drag racing applications we've had great luck shimming down to 0.040" from coil bind at full lift (0.910" min height, 0.870" bind) and still seeing great spring life (no reduction).

First question: Where are you getting the 110 figure from?
Second: If that is accurate, why recommend Manley springs @ 104lbs seat pressure?
Last: Why don't you have the JAM dual springs for sale on the website anymore?

 

[JacksonAuto]

Every engine builder has their own way of doing things and a reason behind it. We will continue to do what we know works best for our customers in terms of performance and reliability. I can't afford to have a spring failure on a customers engine because they request a particular spring. Between the two of us we have close to 60 years of combined experience to fall back on. Valve springs are something we have focused on in all aspects of racing so its nothing and new valves spring technology is what has allowed modern engines to make the power they do. Modern cam profiles couldn't be utilized until recently because the spring technology hadn't caught up yet. The advent of the Spintron machine used in conjunction with high speed cameras and accurate data acquisition has greatly accelerated the development of valvetrain components. The way we look at valve spring selection is the result of these advancements.

 

[RvlutionMtrsprt]

That's nice. You didn't answer any if the questions asked though.

 

[JacksonAuto]

I answered the first two if you read my post. We have our reasons for doing things the way we do based on our own experience, R&D and customer feedback. We don't have the JAM springs anymore because the Manleys are better than what we used to offer.

 

[RvlutionMtrsprt]

Really? You answered where you came up with the 110lb seat pressure figure? I sure don't see that anywhere in your post, nor do you explain why you recommend a Manley spring with 104lb seat pressure if 110lbs is supposed to only be good to 25psi.

 

[JacksonAuto]

The answer is that I'm not going to directly answer your questions. That information is based on years of our own R&D and customer feedback. If you think I'm going to blab that on the internet you're sadly mistaken. Every shop has their own way of doing things and there are many variables which is why it's hard to have conversations like this.

We set up most the Kiggly's around 110lbs, that's where the number came from.

As for the Manleys take a look at the spring rate compared to the Kigglys. That's part of it and if you think they go out of here set up at 104lbs then you're mistaken again. That 104 is also based on an IH of 1.580" which is generous.

I've got a head here right now that was built with the Kiggly's when he planned to run a stock turbo. He upgraded and pushed 35psi through it for a season. We're freshening it up and I just checked the springs earlier this week and they're down by about 15%. There's no doubt in my mind that the high boost took a toll on the springs. Surge, loft and float are tough on parts.