Titanium Valve Spring Retainers Lotus Elan M100 Isuzu Impulse Geo Storm Dohc 4x on 2040-parts.com

These are an exact reproduction of the OEM cast steel valve spring retainers, except made out of titanium.  Just like the OEM valve spring retainers, these light weight titanium valve spring retainers have a single step spring seat, and are designed for use with a single valve spring which is .63 inch ID or larger.  These are NOT designed for use with dual valve springs (spring sets with two springs, an inner and an outer).  (Dual valve springs require two step valve spring retainers and two step lower valve spring seats.) 

Just over half the weight of the original cast steel valve spring retainers.  Billet titanium is also stronger than the original cast steel material. 

Turned from solid round 6Al-4v-Eli alloy titanium.

Titanium valve spring retainers weigh .38 ounces each, or 6.1 ounces for a set of 16.

OEM cast steel valve spring retainers weigh .65 ounces each, or 10.4 ounces for a set of 16.

Just over half the weight of OEM cast steel valve spring retainers.  0.27 oz less each.  4.3 oz. less as a set of 16.

Set includes: 

• Sixteen (16) Titanium Valve Spring Retainers.

Product Benefits

• Reducing valvetrain weight benefits performance and reliability.  The valve assembly is reciprocating (moves up and down).  The engine transmits force through the timing belt and cam sprocket to rotate the camshaft against the lifter and valve assembly.  The force transmitted through the camshaft and cam lobe pushes against the valve spring and the weight of the valve and retainer, to open the valve.  After the peak of the cam lobe moves past the lifter, the spring then pushes against the descending ramp of the cam lobe to close the valve, pulling the weight of the valve assembly shut.  Reducing the weight of the valve assembly (which includes the retainer) reduces the work of the valve spring and the friction between the cam lobe and the lifter.  This results in improved throttle response.
  
• Reduced valvetrain weight also reduces valve float.  Valve float is a function of the height of the cam lobe, the speed of the cam lobe, and the weight of the valve, lifter, and valve spring retainer assembly.  Any combination of these where one or more of the variables exceeds the spring's ability to control valve movement (close the valve) will result in valve lift.  The conventional solution to running high lift camshafts and high engine speed has been to use extremely stiff valve springs, which require more force to move against the lifter, cause more friction and wear, and ironically weigh more, requiring even more stiffness just to handle the added weight of the spring.  Reducing the weight of the valve assembly (which includes the retainer) reduces valve float, because reducing the amount of weight that the spring must move reduces the amount of work that the spring must do to pull the valve closed.  The engine builder's rule of thumb is that every gram (.035 oz) of valvetrain weight reduction results in a 40 RPM increase in engine speed before valve float will occur.  This means that with the standard cam lobe profile, engine RPM can be safely increased because the valve float point has been moved to a higher engine speed, or that the need for larger springs with a taller camshaft lobe is reduced or eliminated by this margin because the valve float point has been increased.
  
• Enhances durability because billet titanium is stronger than cast steel.  Noted Porsche tuner, Rennsport, always uses titanium lifters with their engine builds, due to the frequency of failure caused by cracked or broken cast steel valve spring retainers.  Using valve spring retainers made of stronger material reduces the likelihood of breaking the valve spring retainer.
  
• Broken valve springs are not unknown in Isuzu 4X engines.  Reducing the workload and stress on the spring, and moving the valve float point out of the range of engine operation, will reduce the likelihood of valve spring breakage. 
  
• When valve lift occurs, the valve does not fully close when the cam lobe peak moves past the lifter and the lobe is not pushing the valve open.  When this happens, the distance between the cam lobe and the lifter is wider than the valve gap setting.  As the cam lobe rotates, the valve may slowly draw closed, and may not be closed by the time that the opening ramp of the cam lobe has turned to open the valve again.  If this happens, the lobe will strike the lifter with great force, which is transmitted through the valve, the retainer, and the spring.  This force can cause damage to the valve stem, break the valve spring retainer, and/or break the valve spring.  Moving the valve float point to a higher engine speed reduces the possibility of valve float and valvetrain damage due to valve float.
  
• For owners of Lotus Elan M100, I-Mark RS, or 4XF1 1.8 liter DOHC engines, (which were originally equipped with hydraulic lifters) or those who followed bad advice and switched their solid lifter engines to hydraulic lifters, please be aware that hydraulic lifters weigh 1.6 ounces more than solid lifters, and that increase in valvetrain weight reduces the engine speed that valve float occurs by approximately 1,800 RPM.  While the solid lifter engines have some safety margin above redline before valve float occurs, the hydraulic lifter cars are up against the limit at redline with the stock cam lobe profiles.  This is one of the reasons that the Japanese market Gemini Turbo engine (using solid lifters) has a power output of 180 HP, while the Lotus Elan M100 Turbo engine (using hydraulic lifters) has a power output of only 162 HP.  Switching to lighter weight titanium valve spring retainers will help reclaim some of the performance lost due to the extra weight of hydraulic lifters. 

What is the Isuzuperformance Racing Team?

The Isuzuperformance Racing Team is a hand picked group of professional and semi-professional drivers in Japan and the United States, who compete in Isuzu made cars in road racing, gymkhana, autocross, rally, and drag racing.  Members have distinguished themselves as top tier drivers in sanctioned competition under the Japanese Auto Federation, Sport Car Club of America, Japanese Classic Car Association, and National Auto Sport Association, as well as participation in the events of other organizations such as Redline Time Attack and Katoka Racing Service Battle Royal.

In exchange for review and feedback, Isuzuperformance provides services of design, engineering, and manufacturing of professional racing parts to Team members.  These parts are designed without concern for cost, instead concentrating on three things:

1. Superior and flawless performance.
2. Durability approaching indestructibility.
3. Compliance with the governing racing rules.

These parts are not normally available to the public and are far beyond the budget of the casual car enthusiast or amateur racer.  However, every once in a while, we have extras, and offer those at auction.

Sales Tax:

Missouri buyers pay sales tax on the item cost. Please see Ebay format for current Missouri sales tax rate. There is no sales tax on any item delivered outside the state of Missouri.

Shipping Costs

Valve Spring Retainers are shipped by USPS Priority.  Standard free US shipping is via USPS Priority Small Flat Rate Box.  Please refer to the eBay shipping cost calculator for International shipping options.

All shipments are insured by USPS.

Ebay has removed the 0ptional insurance choice for buyers and placed the onus of delivery upon the seller. In order to comply with Ebay’s policy, we must insure every single package and add the cost of shipping insurance to the shipping and handling fee. This also limits the choices of shipping options to those which are insurable. 

Packaging

Item is packaged in a cardboard box with bubble wrap for shipping.

Payment Information

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