M20 valve springs, beehive and other available options

[jstoll]

Hey folks 🙂 I haven't posted on here in a long time. I'm putting together an engine for my Turbo M20B27 sort of like a super Eta I'm using JE forged pistons (B25 crowns for the 885 head) and Chinese forged rods. Going 9.3 to 1 compression.. I run the engine fully sequentially on ECU master EMU classic with Chevy truck coils near plug ... I have a fresh cylinder head and a cat cams 292/270 cam on the way.. I will be running between 20 and 25 PSI of boost with a GTX 3582 Gen 2 Turbo with a billet wheel external wastegate... The schrick valve springs are not really available now and there are some that are available through bimmer head... But they seem very mild... I intend to spin my engine to 7500 RPM occasionally and have heard about Fiat twin cam inner springs as well as beehive springs, I'm having trouble locating the Fiat springs. Was wondering if anybody knew of good valve spring options that are readily available in the US..
Feel like I'm reinventing the wheel here but I love my old M20 b 27

Any help anybody could offer would be greatly appreciated
Jak

[digger]

BH do sell some you could ask for the specs.

Once upon a time the VAC springs in their kits were Eibach these days i'm not sure and another member said they werent the same brand nor too crash hot these days. i wish i recorded the P/N way back when i installed them in 2008 as they were a good step up from the Schrick. You can also get the Eibach catalogue and start doing some sums to see if anything will work as a replacement inner or a dual set.

PAC do sell PAC-1223 or 1223X beehives https://www.racingsprings.com/index....e-springs.html and CrMo retainer PAC R311 https://www.racingsprings.com/index....oly-steel.html but that's probably over kill.

[jstoll]

thank you ... I think the beehive springs might do. I wonder what the pressure is at 26mm? Ill call them tomorrow
.

[bangn]

9.3 compression, your poor tuner lol what sort of head gasket setup are you going to run?

[digger]

thank you ... I think the beehive springs might do. I wonder what the pressure is at 26mm? Ill call them tomorrow
.

https://www.racingsprings.com/index.php/products/valve-springs/beehive-springs/valve-spring-4241.html

there is enough infor to just work it out. It is ~235lb

[hasa]

5,7kg/mm, sounds like good valve spring for M20.

[jstoll]

9.3 compression, your poor tuner lol what sort of head gasket setup are you going to run?

I have a tuning and fab business and was going to go 10:1 .. it's on E85 .. I use a stock style composite head gasket, block is oringed and use studs...
I have a friend with an 11:1 m52b28 that made almost 700whp on E85 using a turbo...

The more power you make NA the more power per pound of boost you make...
A 200 ho na engine will make 400 at 15 lbs boost and a 300 HP na engine will make 600 HP on 15 lbs and so on

I've been tuning for decades.. 9.3 is not an issue, in fact things like thicker head gaskets can cause quench problems which can lead to an engine being more knock limited... As an example when I ran B27 pistons my engine was more knock limited even though the compression was lower then stock..
I ran early B25 pistons for a while which I whittled down on my lathe to clear the crankshaft and they were so much better then B27 pistons...

[jstoll]

I called them up and spoke with them on the telephone🙂 the retainers that were listed above or not correct, it is the 312 retainer that is correct for that spring with a 7 mm valve stem... The 311 retainer is for a 8 mm stem and does not fit the spring... And speaking with the person, the seat pressure is 90 and at 11.5 mm of lift. The spring pressure is 209... Does not exactly match the recommendation on the cam sheet but I think this is a good choice,

[digger]

Yeah my bad it’s the ford modular part number.
you are supposed to shim the beehives to maximise performance obviously noting the clearance to coil bind or stem seal clearance .
I wouldn’t run that catcams I’d run a naturally aspirated cam with wideish LSA