New Cam Installed and a few questions

Foster#17

Foster#17

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Apr 1, 2015
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I finally got around to installing my new cam (hamilton 188/220) exhaust manifold, and intercooler! What a treat it was to get the new tappets installed.. I am very pleased with how the cam seems to spool! I noticed that my cruising egts actually have raised 100 degrees when climbing a mountain.(low rpms in overdrive) before they would be around 950 and now they're hitting 1050? I thought for sure the more aggressive cam and intercooler would drop the egts! What is going on here?? I am guessing my WOT egts will be lower because the cam will be flowing a lot more air then but I haven't had a chance to give it a try yet with the icy roads. Is this normal for the egts to raise with a larger cam and lower rpms?
 
I'm speculating here, but I'm assuming because you're powerband/efficiency range has now moved to the right, that it won't be as efficient at the same lower rpm's. Hence, the higher egts. I wouldn't worry about 1100*.
 
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madmikeismad said:
I'm speculating here, but I'm assuming because you're powerband/efficiency range has now moved to the right, that it won't be as efficient at the same lower rpm's. Hence, the higher egts. I wouldn't worry about 1100*.
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Right that's what I was thinking and I know 1100 isn't anything to worry about, it hit 1500 when racing but I was just using the cruising temperatures as an example to see what was going on! Thanks
 
How steep are these grades you're talking about, how heavy is the truck, and what rpm/mph is cruising for you?
 
Just curious but why would you want the power band moved higher in the rpms if these motors are designed to make power on the lower rpm scale and it's easier on interals to not spin them past 4K rpms so what would be the greater benefit? Seems like it would be the opposite of what one would want. Wouldn't it be more beneficial to make power down low so it spools easier and pulls faster and harder at lower rpms ?
 
Green2015 said:
Just curious but why would you want the power band moved higher in the rpms if these motors are designed to make power on the lower rpm scale and it's easier on interals to not spin them past 4K rpms so what would be the greater benefit? Seems like it would be the opposite of what one would want. Wouldn't it be more beneficial to make power down low so it spools easier and pulls faster and harder at lower rpms ?
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Kills driveline, transmission especially.
 
Oh ok. I thought guys were losing power from cam swaps on low end tq numbers vs stock cams is why I asked
 
Marq92 said:
The 188/220 will help from idle to 4200.
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Off idle the 188/220 moves air great in my 6.7. Now if I lug it say in 5th gear feathering the throttle to accelerate then I'll see higher egts (1000*), but soon as turbos light I'm not breaking 1100* at wot.
 
Yeah but so will stock cams. I never see over 1,000 towing 15,000lbs up an incline and that was with the smaller 67mm now with my compounds I'm sure I'll never see over that ever with only my 100% overs but mine ran great low end and up to 4,000rpms pulled the same through the whole rpm range.
 
You changed three components so it is hard to isolate what caused what. What rpm are you at 1050 degree? Also what boost?

Intercooler- The more boost you run the hotter the air will become pre-intercooler which is when the intercooler will show gains. If you are only running 5-10lbs of boost the intercooler will not show you much benefit like you will see at 25lbs + when you actually have heat in the intake air that needs to be cooled.

manifold- Sometimes the manifold will have higher volume which can reduce exhaust velocity and make a more sluggish spool at lower rpm. This is a tradeoff, because as rpm, boost pressure and drive pressure increase, the increased volume and shape of the manifold can help efficiency and flow. What boost and drive pressure were you at pre-swap and post swap on the same grade? Have you done a WOT run and compared EGT before and after the swap?


Cam- The 188-220 does trap more air at lower rpm which cools down egt. It also opens the exhaust a bit sooner which creates a larger pressure pulse to hit the turbine wheel. Since we open the exhaust a bit sooner, often time at low rpm, in a lugging situation, you might see a small increase in EGT even though there is a more complete burn happening on the power stroke. I would be interested in feedback on a WOT run. If you think this is the case, try adjusting the exhaust lash to .025" and see how that affects egt. If it does nothing, then change the intake lash to .015" and do the same Lug up the hill. If either one of these makes a positive change, then your cam is a bit big for your application. I do not know who spec'd it in, but if you are after low rpm towing/street performance, you might be better off with the 182-214 or the 178-208. the 178-208 will greatly help low rpm performance at the cost of higher rpm performance compared to the 188-220. That being said, it will still outperform the stock cam across the entire rpm range. If you bought from us and we spec'd it in wrong, I will be happy to take the used 188-220 back and trade you into the cam of your choice.

Cheers,

Zach
 
Texashighways said:
You changed three components so it is hard to isolate what caused what. What rpm are you at 1050 degree? Also what boost?

Intercooler- The more boost you run the hotter the air will become pre-intercooler which is when the intercooler will show gains. If you are only running 5-10lbs of boost the intercooler will not show you much benefit like you will see at 25lbs + when you actually have heat in the intake air that needs to be cooled.

manifold- Sometimes the manifold will have higher volume which can reduce exhaust velocity and make a more sluggish spool at lower rpm. This is a tradeoff, because as rpm, boost pressure and drive pressure increase, the increased volume and shape of the manifold can help efficiency and flow. What boost and drive pressure were you at pre-swap and post swap on the same grade? Have you done a WOT run and compared EGT before and after the swap?


Cam- The 188-220 does trap more air at lower rpm which cools down egt. It also opens the exhaust a bit sooner which creates a larger pressure pulse to hit the turbine wheel. Since we open the exhaust a bit sooner, often time at low rpm, in a lugging situation, you might see a small increase in EGT even though there is a more complete burn happening on the power stroke. I would be interested in feedback on a WOT run. If you think this is the case, try adjusting the exhaust lash to .025" and see how that affects egt. If it does nothing, then change the intake lash to .015" and do the same Lug up the hill. If either one of these makes a positive change, then your cam is a bit big for your application. I do not know who spec'd it in, but if you are after low rpm towing/street performance, you might be better off with the 182-214 or the 178-208. the 178-208 will greatly help low rpm performance at the cost of higher rpm performance compared to the 188-220. That being said, it will still outperform the stock cam across the entire rpm range. If you bought from us and we spec'd it in wrong, I will be happy to take the used 188-220 back and trade you into the cam of your choice.

Cheers,

Zach
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I have had no problems with the cam! I really like it but was just wondering if it was what caused the higher egts in the low rpm range (around 1500rpms) it spools really fast from a dead stop compared to the stock one! I did some WOT runs and it feels to have really made a difference! Egts do seem to stay down more at higher rpms! I went with this cam because I race the truck but I also tow and will be doing a set of compounds soon.
 
Oh okay. I am the same way, in that I want to be able to tow 20,000# and dust the occasional gasser. Any data you give can help me help you.
 
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