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| Need help with Engine build https://slantsix.org/forum/viewtopic.php?t=63385 |
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| Author: | Mopar93 [ Tue Mar 12, 2019 7:14 am ] |
| Post subject: | Need help with Engine build |
Alright so I’m building a 225 /6 for a buddy he wants 198 7.005 inch rods, 10:3-1 cp wiseco pistons, comp cam .440 lift, and the block is bored .045 over and he wants a 3 angle valve job with a 4bbl intake and header what kind of hp numbers should we expect? Should we get the head potted with bigger valves? And what would the cost be ballpark ramge and is that a good camshaft lift for the work being done? |
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| Author: | DadTruck [ Tue Mar 12, 2019 1:51 pm ] |
| Post subject: | Re: Need help with Engine build |
Welcome to this site, howeve speculating on cam lift is maybe a bit further down the rebuild road. To begin with: What is the vehicle? car or truck What transmission type, if auto, is the converter being upgraded? What rear end ratio? What is the intended use? Daily driver, full time racer? Then you can talk about lobe separation and duration and then cam lift. |
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| Author: | Mopar93 [ Tue Mar 12, 2019 2:05 pm ] |
| Post subject: | Re: Need help with Engine build |
1971 Dodge Dart swinger, 904 tranny, 8 3/4 with 3.91s, street and strip car with stock converter |
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| Author: | DadTruck [ Tue Mar 12, 2019 2:37 pm ] |
| Post subject: | Re: Need help with Engine build |
You have a nice start on street /strip motor. On the pistons, I would consider going bigger than .045 The larger bore helps to reduce valve shrouding. There are slants that easily take a larger bore, but have the block sonic checked. And yes, oversized valves and porting, mainly work in the valve pocket would be helpful. On the 3 angle valve job, that is the place to spend time and money to get it right. Lot of performance slants run 105 or 106 LSA, with the cam installed at 100 ICL. What duration cam are you looking at. Many folks here go with reground cams from Oregon Cam Grinders. |
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| Author: | Mopar93 [ Tue Mar 12, 2019 2:46 pm ] |
| Post subject: | Re: Need help with Engine build |
I actually just took the block to my machinist today and he said he’s wants to go 60 over with th block and the camshaft was a 260/260 duration I’m not the best with performance cams I’m use to stock rebuilds lol so I really need some help with the cam specs |
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| Author: | DadTruck [ Tue Mar 12, 2019 3:54 pm ] |
| Post subject: | Re: Need help with Engine build |
Is the 260 advertized or @.050? |
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| Author: | Mopar93 [ Tue Mar 12, 2019 5:29 pm ] |
| Post subject: | Re: Need help with Engine build |
It’s advertised but at 050 it’s 212 and 212 |
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| Author: | DadTruck [ Tue Mar 12, 2019 5:37 pm ] |
| Post subject: | Re: Need help with Engine build |
That is about what I have in my slant - low rpm torque- tow daily driver D150, You can go bigger in a light A street - strip A body. |
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| Author: | Charrlie_S [ Tue Mar 12, 2019 5:52 pm ] |
| Post subject: | Re: Need help with Engine build |
Personally, I think 10.3 CR and that small cam, is not a good combo. Correct me if I'm wrong. |
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| Author: | Mopar93 [ Tue Mar 12, 2019 6:20 pm ] |
| Post subject: | Re: Need help with Engine build |
What spec camshaft would you fellas recommend? |
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| Author: | Charrlie_S [ Tue Mar 12, 2019 6:39 pm ] |
| Post subject: | Re: Need help with Engine build |
I'm thinking, the cam is probably OK, but not with that CR. and a stock converter. Going to be hell to tune on pump gas. I have a 64 Valiant with a 170 at 9.5 CR and the small (244 dur and .436 lift) MP cam, with a stick and it was hard to keep it from pinging on pump gas. You folks with street drivers help out, here. I could be all wrong. |
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| Author: | DadTruck [ Tue Mar 12, 2019 6:54 pm ] |
| Post subject: | Re: Need help with Engine build |
Quote: 10.3 CR and that small cam, is not a good combo.
exactly, with a cam that size I am running 8.5 static compression in the D150and get cranking pressures in the 180 range. beyond that, that particular cam with a 260 advertised and a 212 @ .050 duration, is not a cam that takes advantage of the .904 mopar lifter in the slant. Subtracting advertised duration from duration @.050 gives one an idea of the cam lobe speed. That particular cam is 260-212=48 and that is pretty slow. For a cam recommendation, the poster should read through some of the builds in the engine build matrix, http://www.slantsix.org/forum/viewtopic.php?t=23314 and some of the other cam articles on line like this one http://www.elgincams.com/campaper.html and this one https://www.hotrod.com/articles/0607phr ... ft-basics/ to have a better handle on cam shaft variables, then plan his motor. |
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| Author: | Dart270 [ Wed Mar 13, 2019 5:12 am ] |
| Post subject: | Re: Need help with Engine build |
Get at LEAST the #34 cam from Oregoncams, and I would go bigger. The biggest HP gains will be from head porting and bigger valves, combined with the high CR and a fairly large cam. I will try to work up a cam profile for you that you can order from Oregoncams. Lou |
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| Author: | Charrlie_S [ Wed Mar 13, 2019 5:19 am ] |
| Post subject: | Re: Need help with Engine build |
Remember the OP is planning on a stock converter, so that will limit cam selection. |
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| Author: | Mopar93 [ Wed Mar 13, 2019 6:15 am ] |
| Post subject: | Re: Need help with Engine build |
If need be a bigger converter can be bought to accommodate the best performing camshaft you guys really opened my eyes about cams I never knew there was this much thinking involved lol your help is greatly appreciated |
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