Valve Springs

[neil68]

I have a set of JPM MS230 heads in my street strip Beetle.  Also, have a spare set of new CB VW650 dual springs.  Will these work as suitable replacement springs in the JPM heads?

The Beetle revs to around 7900 rpm in the 1/4-mile and I use a rev limiter.

Thanks.

[TexasTom]

I checked my spare JPM springs and they are the same OD as stock.
I assume the CB springs are also 1.26" so all should be the same but the pressures.

Hope this helps ... 
TxT

[ED2.4]

Hi,
VW650 and OTEVAs are really close , a bit less pressure with OTEVAs ,around 410Lbs @ coil bind (0.830"),
both are very nice products

[neil68]

Thank you both!!

I have over 250 races on the original Oteva springs, and started to experience some valve float at the end of last race season.

0.599" lift with the Raptor cam (10.8 mm X 1.41 Scat rockers), so I think I will go ahead and install the CB springs for next season.

Thanks again.

[K-Roc]

Hi Niel, If i recall you have long T2 style valves in your JPM heads so you need to double check your free intalled height, before you intall the CB650'S and shim them accordingly,  the 650's like an installed height of no more than 1.540"

When a valve spring is installed "Looser" than it's  reccomended installed height it can have problems with harmonics. You could probably go a little higher but I wouldnt go too much, Pat Downs can probably tell you exactly how far you can safely push the installed height without any side effects.

Cheers

[TexasTom]

minimum & maximum heights and pressures listed here:

http://www.cbperformance.com/ProductDetails.asp?ProductCode=1493

[ED2.4]

Hi,
in double VW springs configuration ,MS230 have around 1.57" of  installed height with Jpm Ti retainers

[andy198712]

minimum & maximum heights and pressures listed here:

http://www.cbperformance.com/ProductDetails.asp?ProductCode=1493

the max installed height is what a CB 044 head comes at.... funny that mind you thats with no shims and the spring sitting on the head bare

[neil68]

Update:  Well, since we're indoors while a spring blizzard buries us in snow here in Canada, I finally got around to swapping out the JPM Oteva valve springs.

When I measured the CB VW650 springs, they turned out to have the identical dimensions to the Oteva springs...in every measurement, so it was a straight swap.  Installed height was 1.55".  I could certainly feel the extra pressure of the CB springs when installing, so I think the Oteva's have lived a hard life at the drag strip the last two years...

[neil68]

Update:  So another race season is coming to an end and I thought I would update this thread.  The CB VW650 springs have worked very well so far, and were identical to the original Oteva springs in almost every way...sizing, spring pressure, etc.

I am really starting to like the Raptor cam.  At first I thought it was too much lift (0.599"/15.23 mm) for a short duration (274 degrees @ 0.050"/1.27 mm).  However, it looks like I just wasn't giving the cam enough rpms.  Now I'm pushing to 7700 before shifting and have got the ET down to a best of 12.658 seconds @ 106.44 MPH/170 km/h.

I still don't do a burnout, and keep lots of air pressure in the tires (to save the transaxle), but it's been lots of fun.  Heavy street Beetle 2,045 lb/930 kg (with driver).  On the last race of the season, I might drop the air pressure in the M&H's and see if I can hook up better...

[ED2.4]

Hi,
nice results,  i bet it will continue down the ETs 

[NoBars]

Get that car close to 1800 pounds and it will go well into the 11s, and be easier on your transmission.

[spanners]

Oteva is the brand name of the swedish v/s wire, many other brands will use the same wire.