Engines and Components› Camshafts and Valvetrain

Tomei

Engine Component Spring Seats

$9.90

SKU: TA305A-MT01C

In Stock
In Stock
Ships by Sep 9
Free Shipping over $200
$100 Minimum Order
30 Days Return
INSTALL DIFFICULTY
DIY PRO SHOP

Moderate — 2–4 hours

Overview

This adjustment is crucial for race engines aiming to increase RPM without hesitation. By utilizing these spring seats, the objective of blue printing an engine—achieving tighter clearances and uniform specifications—can be met at a fraction of the cost of traditional methods.
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This process is essential for high-performance and race engines that require precise tuning to achieve higher RPM ranges smoothly and without issue. Blueprinting an engine, a standard procedure for optimizing clearances and ensuring uniform specifications, can be a time-consuming and costly service. Tomei's valve spring seats offer a more cost-effective solution to achieve similar objectives. By employing these valve spring seats, engine builders can fine-tune the load applied to each spring to match different spring rates. This ensures that all components are balanced to tighter clearances than manufacturer specifications, preventing potential issues such as valve spring surge, sticky operation under load, power loss, and in severe cases, cotter pin disengagement which can lead to significant engine damage. For example, when installing Tomei Type A valve springs in an RB26 engine, these seats can restore the spring load to the desired 24kg range after a valve job has reduced it below 20kg, allowing the engine to rev freely. This specific valve spring seat is 0.5mm thick and comes in a set of 8 pieces. It is engineered for compatibility with a range of performance engines, including Mitsubishi 4G63 (EVO 1-9) and various Subaru EJ series engines (EJ205, EJ207, EJ255, EJ257). It is suitable for applications such as the Mitsubishi Lancer EVO 1-9 (1992-2007), Subaru WRX (2015-2021), and Subaru WRX STI models.

Product descriptions are provided by our supplier partners and may not always be perfectly accurate. Not sure this fits? or call (760) 282-4645 and we’ll verify before you order.

Fitment

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Specifications

BrandTomei
Part NumberTA305A-MT01C
CategoryEngines and Components

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Returns & Fitment

Built for enthusiasts. Every order is backed by our 30 day return window on eligible items. Unused and uninstalled products may be returned with approved RMA and no restocking fees when received in new condition. Orders placed through the MOTORMIA app with a complete build qualify for our Fitment Guarantee — free return shipping if the part doesn’t fit your exact setup. The guarantee covers fit only; installation must follow manufacturer instructions, and we recommend a qualified shop for parts marked Difficulty 4–5.

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Shipping

Orders are processed in 1–3 business days. In stock parts ship promptly from our partner network. Special-order items either aren’t currently stocked or are built to your spec — expect 4–6 weeks. If a part goes on backorder while your order is in the queue, we’ll reach out and work through discounted alternatives together.

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