Topic: Improving camshaft towers stability

[livefast_dieold]

Hi there,

so my DP315 camshaft is great (used with stronger valve-springs), but it's really stressing the towers, and apparently also the chain tensioner (check Franciacorta race reports)...

I'm already using helicoils to improve the original bolts grip, so I was thinking to go with the popular cam tower stabilizers welded on the cover. Does anyone have the precise references on where the stabilizers should be welded?
Any other techniques to consider?

On the chain tensioner side, what the general experience using high performance cams and original rollers? Should I trust them or would it be better to look for something else?

Thanks in advance for the suggestions!
Ciao
Riccardo

[MCRider]

Cycle-X can provide both Cam Cover reinforced and HD tensioner.

http://www.cyclexchange.net/Engine%20Parts%20Valve%20Trane.htm

http://www.cyclexchange.net/camshaftpage.htm

I bot my HD tensioner from M3 Racing. Cycle X was not available at the time. It really quiets it down by supporting the nearly full run of the chain.

[754]

Easy to mark out in a drill press. 
 Mount center drill in chuck. Slide head on table, figure out a way to clamp lightly.
With camtower on head,  line up point on camtower where you want the bolt to bear down,clamp head.
Then slip on cam cover with dowels in place, then drill into cover till it breaks thru, or at least has a good start. Repeat on other 7 holes.
You can use thin spacers, to aid in lifting off valvecover...

 Now you are ready to weld on the supports.

[madmtnmotors]

Easy to mark out in a drill press. 
 Mount center drill in chuck. Slide head on table, figure out a way to clamp lightly.
With camtower on head,  line up point on camtower where you want the bolt to bear down,clamp head.
Then slip on cam cover with dowels in place, then drill into cover till it breaks thru, or at least has a good start. Repeat on other 7 holes.
You can use thin spacers, to aid in lifting off valvecover...

 Now you are ready to weld on the supports.

Doesn't get any more accurate than that! 

[livefast_dieold]

Easy to mark out in a drill press. 
 Mount center drill in chuck. Slide head on table, figure out a way to clamp lightly.
With camtower on head,  line up point on camtower where you want the bolt to bear down,clamp head.
Then slip on cam cover with dowels in place, then drill into cover till it breaks thru, or at least has a good start. Repeat on other 7 holes.
You can use thin spacers, to aid in lifting off valvecover...

 Now you are ready to weld on the supports.

Nice suggestion!!! Thanks!

[scottly]

Hi there,

so my DP315 camshaft is great (used with stronger valve-springs), but it's really stressing the towers, and apparently also the chain tensioner (check Franciacorta race reports)...

Are you using lightweight valve train parts, such as titanium adjuster nuts and valve spring retainers? The less weight the springs have to control, the weaker they can be before valve float sets in at the same RPM, reducing the stress. How high are you revving the motor?   

[70CB750]

Cycle-X can provide both Cam Cover reinforced and HD tensioner.

http://www.cyclexchange.net/camshaftpage.htm

I bot my HD tensioner from M3 Racing. Cycle X was not available at the time. It really quiets it down by supporting the nearly full run of the chain.

The whole thing or just this part? 

[MCRider]

The whole thing, internal parts. The M3 part is a long slide that replaces the center wheel. The Cycle X part is about 1/2 of the way down on the 2nd link, with a yellow banner "Cycle X Racing Cam Chain Tensioner". It maintains the OEM design.

[70CB750]

Thank you, I may treat Dorothy to it, the cam chain on Red makes ugly noise in idle.

[livefast_dieold]

Hi there,

so my DP315 camshaft is great (used with stronger valve-springs), but it's really stressing the towers, and apparently also the chain tensioner (check Franciacorta race reports)...

Are you using lightweight valve train parts, such as titanium adjuster nuts and valve spring retainers? The less weight the springs have to control, the weaker they can be before valve float sets in at the same RPM, reducing the stress. How high are you revving the motor?   

No lightweight parts at all!

On revving I prefer not to answer :-)

[754]

I used to reveal my 315 to 10,5000 constantly,  often higher... For a long long time..
 I had some kind of springs, maybe RC?  Stock top collars..
 When I finally opened it up after 20 plus years, I don't recall any stripped threads.

 As to the welded up covers, I had heard that.....back in the day they had been using overly strong valves springs, vs made to order for these engines.... And that caused a lot of the problems......FWIW..

 I still think the welded up covers look pretty trick..If the welding is clean..
 Seen a few with messy welds.

[MRieck]

I used to reveal my 315 to 10,5000 constantly,  often higher... For a long long time..
 I had some kind of springs, maybe RC?  Stock top collars..
 When I finally opened it up after 20 plus years, I don't recall any stripped threads.

 As to the welded up covers, I had heard that.....back in the day they had been using overly strong valves springs, vs made to order for these engines.... And that caused a lot of the problems......FWIW..

 I still think the welded up covers look pretty trick..If the welding is clean..
 Seen a few with messy welds.

My experience as well especially if you use helicoils for the 2 long cam tower bolts. The cam cover stuff was for the Pinto springs people used back in the early days.

[bwaller]

Funny huh? Pinto springs didn't help the Pinto. 

[MRieck]

Funny huh? Pinto springs didn't help the Pinto. 

.....and nothing could help the Vega (not even Cosworth).

[bwaller]

Funny huh? Pinto springs didn't help the Pinto. 

.....and nothing could help the Vega (not even Cosworth).

Oh man, we have come a long way!

[livefast_dieold]

So this was the solution I've adopted: 8mm studs to keep the camshaft towers in place!
The rockers spindles have to be cut in half... and re-assembly can be quite tricky (the spindles were passed trough the camshaft sprocket holes!).

[70CB750]

Interesting.

[Don R]

 Speaking of valve springs I took a 750 apart that had very thick short springs and a thick spacer under each spring. W0W. They had to have a ton of pressure as evidenced by the keepers pulling through the retainers. I know you need to get the spring close to coil bind to control cavitation but these looked extreme.

[MRieck]

Speaking of valve springs I took a 750 apart that had very thick short springs and a thick spacer under each spring. W0W. They had to have a ton of pressure as evidenced by the keepers pulling through the retainers. I know you need to get the spring close to coil bind to control cavitation but these looked extreme.

They sound like RD springs with the thick bases. Not sure what you mean Don by "cavitation" with the springs. Coil bind is what I have looked out for