Viper w/srx heads

2muchhp

2muchhp

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Jan 18, 2007
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Traverse city, MI
I have been reading you need 2 water rails to do this ,however cant see why
the need for 2. Can anyone explain? I just picked up a Viper and want to get moving transfering over all the parts I can from my srx.
thanks.
 
I installed SRX heads on a bb 835 viper. It was a good mod for that engine. Good luck with it and make sure as staggs said you cc the heads and have them cut for the proper squish and compression ration.
 
even better, but you still should talk to an engine builder about the heads. the porting on the viper cyls is different then the srx so you may still need to make some changes to the domes.
 
Wow that looks sweet staggs.You just cut the end off and weld an elbow to the plate?I would just need to find an aluminum elbow or try and fab something up.
 
I removed the t-stat from the SRX water rail (Viper has the t-stat in a seperate housing). Used the elbow off a stock Viper rear crossover tube and welded it to a piece of aluminum plate and then to the water rail. be sure to weld up the bolt holes in the water rail before you weld the plate on.
 
How would the porting effect the heads.I was hoping to machine the viper jugs for o-rings,check squish with srx base gasket and be good to go. Of course its never as easy as it seems.
 
I'm not saying you can't do that, I would just check with someone who knows for sure. Engine building isn't my department. I bolt them together all the time but I leave the actual figuring to the pros.
 
2muchhp said:
I am going to o-ring the Viper jugs,I would rather do that than cut the heads.Just seems better
Click to expand...

youll still need to cut the heads, as the srx heads if from a 98-99 srx will be marked as 8dn-00 are 26cc, the srx heads from 2000-02 which will be casting 8dn-10, are 24cc.
A viper in 2 of the cylinders are 21cc and 24cc in the pto cylinder. So you can see even with o-ringing the viper cylinders youll be lowering the compression putting srx heads on with no headwork. A viper also has a higher exhaust port then a srx and this lowers the compression even more. If you use 24cc heads youll be around 110-115lbs of compression where as you should be around 130lbs. The precise numbers will depend on the compression guage but this is what it would read on mine, you get the idea anyways.

When you lower the compression the engine will be more lazy feeling down low and thru the midrange.
 
I know what you mean,my srx is a 01 so 24cc is good. My srx checks 130 now so yea right I want to stay about there,cant accept lazy after siding an srx for years.I am thinking with an o-ringed jug its easy to shave and check comp. and repeat until it is right,then machine the other 2 the same amount.Along with squish check as I go.Any thoughts on this.
 
You have the basic idea, however, you really cant just do it that way and end up with 3 heads the same spec when your done.
You should measure all 3 heads first and make the other 2 match the smallest 1 first, then go about your checking so youll have all 3 the same when your done. You might be suprised at the variances you can see between production parts.
 
I always liked the gasket for the reason of changing compression for racing. I had cut jugs I could bring to stock height running 4 gaskets, run a full on super unleaded on the trail, run one on the grass. very versatile. Later I had a few sets of heads chambered differently and it wasn't needed but at first, it sure saved some money.
 
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