Cam comparison question for Evo motor
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Road Master
Joined: Apr 2017
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From: out there
Cam comparison question for Evo motor
Hi guys,
just have a question about possibly changing out the bolt in EV13 cam in a '98 Road King.
The plan was to install Wiseco 10-1 compression pistons, cc the heads and a bigger cam.
WilI I gain much?
Which cam would suit the higher compression??
(I'm doing a top end rebuild anyway, hence my question).
Thanks.
just have a question about possibly changing out the bolt in EV13 cam in a '98 Road King.
The plan was to install Wiseco 10-1 compression pistons, cc the heads and a bigger cam.
WilI I gain much?
Which cam would suit the higher compression??
(I'm doing a top end rebuild anyway, hence my question).
Thanks.
Road Master
Joined: Sep 2021
Posts: 759
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From: Under the affluence of incahol.
Depends on what sort of performance you want the cam to give you. I fitted an Andrews EV13 to my 95 RK (stock compression) and am very happy with it. Gives lots of extra low and midrange power for two-up riding on steep twisty roads. Others prefer the EV27 that gives more top end power. I think bumping the compression up would get the best out of the cam but I just can't be azzed tearing the top end apart.
Last edited by PeterB; Aug 20, 2024 at 02:37 AM.
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From: Poolville
Best combination I ever saw was a 10.2:1 comp with stage II heads ( 1.90/1.61 valves and 83 cc chambers) with a Woods W6 cam.. High 80's Torque and HP.. Roughly a 20% gain over stock if not more.. if you get the heads done properly with .600" capable valve springs the cam choices are unlimited and with the right compression will put you into the 90's tq/HP...
Keep in mind you have a heavy bike so most will tend to build around torque not HP...
Keep in mind you have a heavy bike so most will tend to build around torque not HP...
Last edited by 98hotrodfatboy; Aug 20, 2024 at 02:43 AM.
Thread Starter
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Road Master
Joined: Apr 2017
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From: out there
Best combination I ever saw was a 10.2:1 comp with stage II heads ( 1.90/1.61 valves and 83 cc chambers) with a Woods W6 cam.. High 80's Torque and HP.. Roughly a 20% gain over stock if not more.. if you get the heads done properly with .600" capable valve springs the cam choices are unlimited and with the right compression will put you into the 90's tq/HP...
Keep in mind you have a heavy bike so most will tend to build around torque not HP...
Keep in mind you have a heavy bike so most will tend to build around torque not HP...
I don't have a machine shop here that can do what you've suggested with the heads, but I can get a valve job and cc'd to 83cc.
10.2 comp should be easy to achieve, so the Woods W6 cams could be a good option.
The other cam that might work at that compression is the Vthunder 3020 ?? It has similar specs the the W6....
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Road Master
Joined: Apr 2017
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From: out there
Hey eighteight, are you recommending the ev46 cam?
I'm guessing this cam would probably benefit from the extra compression of the Wiseco 10-1 pistons.
I'm guessing this cam would probably benefit from the extra compression of the Wiseco 10-1 pistons.
Seasoned HDF Member
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From: OH
Just a reference point for what is basically a bone stock EVO
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Stellar HDF Member
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From: College Station, TX
I didn't see where you mentioned your riding style. The cam you currently have provides good torque (which is more important than HP) from idle to around 4000-4500 rpms (where it start tapering off) or so depending on other components, which is good for acceleration from stops or riding two up or packed with gear. But with early closing intake valves (31 degrees) you don't want too much more compression because cylinder pressure will be increased. I'd also check the cylinder bases to be sure they are flat and then set the squish band when assembling the top end by using the proper base and head gaskets.
The 3020 has a later intake closing (42) and more duration and will provide more mid and top end power, but you will lose some bottom end torque. So it better suited for a lighter bike. Going to 10:1 compression will help the low end torque some, which you need with a heavy bike like a Road King. So you can gain some additional torque back by bumping the compresion a little, but depending on where you live I'd be cautious of exceeding about 9.2-9.5:1 unless you have regular access to 93 or better octane gas and the ambient temperature doesn't regularly exceed 90 degrees.
Basically, to get more power in the mid and higher RPM's, you will lose some low end power. You are riding torque, not HP. So go with a combination that best suites your riding style.
Paul
The 3020 has a later intake closing (42) and more duration and will provide more mid and top end power, but you will lose some bottom end torque. So it better suited for a lighter bike. Going to 10:1 compression will help the low end torque some, which you need with a heavy bike like a Road King. So you can gain some additional torque back by bumping the compresion a little, but depending on where you live I'd be cautious of exceeding about 9.2-9.5:1 unless you have regular access to 93 or better octane gas and the ambient temperature doesn't regularly exceed 90 degrees.
Basically, to get more power in the mid and higher RPM's, you will lose some low end power. You are riding torque, not HP. So go with a combination that best suites your riding style.
Paul
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Seasoned HDF Member
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From: OH
I didn't see where you mentioned your riding style. The cam you currently have provides good torque (which is more important than HP) from idle to around 4000-4500 rpms (where it start tapering off) or so depending on other components, which is good for acceleration from stops or riding two up or packed with gear. Paul
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Road Master
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From: out there
OK, sure. But how does that fit with my plan to use the 10-1 compression pistons? Just a bit confused as to what you're suggesting.
Thanks
Thanks