2003 Speed DYNOJET results

Message

ryanclark75 · #11 Post by **ryanclark75** » Wed Jul 01, 2009 10:29 am

[quote name='peterock' date='Jul 1 2009, 05:10 AM' post='206809']
Oversized valves may be hurting you. Once you have everything assembled, you need room around the valves and there isn't much there between the valve and cylinder wall. Bigger isn't always better.
[/quote

It was my mistake they were higher compression not larger and it was the kit from Black Widow that says These intake valves have been totally redesigned to raise the performance of your engine. They are re-desigend on top to allow better flow of air/fuel into the cylinder, and the bottom of the valve is no longer convex (as on all the factory valves). This will help increase compression by eliminating this extra room in the head. NOTE: This is NOT a drop-in item. The intake valve seats will have to be re-shaped to allow these valves to seat properly."

kdeal · #12 Post by **kdeal** » Thu Jul 02, 2009 10:45 am

The valves you are refering to are not hurting your performance. The reason they are termed "high compression" is that they have no dish to the valve what so ever and there for take away some of the cc's of volumn from the combustion chamber. They also happen to be shorter in length which is why they are not a drop in. The valves have to be "sunk" into the head a few thousandths. As long as they were installed properly this should have no bearing on lower performance. If the motor feels real strong but you are not getting the HP numbers on the dyno, my best guess is a cam timing or mapping issue. I was off 10hp once on a big motor just due to cam timing. With your set-up, I would at least be running 108/106 degrees. Remember mapping also includes ignition timing changes as well. Too much ignition timing up high in the rpm range can cause the same problems.

ryanclark75 · #13 Post by **ryanclark75** » Thu Jul 02, 2009 10:54 am

QUOTE (kdeal @ Jul 2 2009, 05:45 AM) <{POST_SNAPBACK}>

The valves you are refering to are not hurting your performance. The reason they are termed "high compression" is that they have no dish to the valve what so ever and there for take away some of the cc's of volumn from the combustion chamber. They also happen to be shorter in length which is why they are not a drop in. The valves have to be "sunk" into the head a few thousandths. As long as they were installed properly this should have no bearing on lower performance. If the motor feels real strong but you are not getting the HP numbers on the dyno, my best guess is a cam timing or mapping issue. I was off 10hp once on a big motor just due to cam timing. With your set-up, I would at least be running 108/106 degrees. Remember mapping also includes ignition timing changes as well. Too much ignition timing up high in the rpm range can cause the same problems.

Awesome info, thanks for the schooling, I actually needed it. I think once I get it re-dynoed and we look at the ECU mapping at Rage ATV in Houston we will get it right(this time I will be there myself to oversee). To bad I have to sell this bad boy very soon anyways. My wife just had our fourth daughter so it has to go, so I can finish my jeep project. I just want this HP problem corrected. I like my projects perfect!!! And I hate to not know why something is not doing what it is supposed to!!thank you for the info.

peterock · #14 Post by **peterock** » Thu Jul 02, 2009 10:59 am

If the valves have to "sunk" into the head a few thousands, isn't that taking away from the compression you gain from not having the dish? Fill the dish in but then slide the entire head of the valve deaper into the pocket is going to end up working against what you were just trying to achieve with the new 'high compression" valves.

Kind of sounds like they aren't going to be worth the extra $100.

kdeal · #15 Post by **kdeal** » Thu Jul 02, 2009 6:18 pm

I am not trying to justify the valves or their usage, but there are not the problem in this case. The difference they are sunk are not as much as they displace in the combustion chambers. They also have a steeper angle on the back side to add some additional flow as well. Are they worth the extra money? Depends on what you are looking for. I personally do not see any issues with the stockers to go to the extra labor to install them.

ryanclark75 · #16 Post by **ryanclark75** » Thu Jul 02, 2009 7:19 pm

QUOTE (kdeal @ Jul 2 2009, 01:18 PM) <{POST_SNAPBACK}>

I am not trying to justify the valves or their usage, but there are not the problem in this case. The difference they are sunk are not as much as they displace in the combustion chambers. They also have a steeper angle on the back side to add some additional flow as well. Are they worth the extra money? Depends on what you are looking for. I personally do not see any issues with the stockers to go to the extra labor to install them.

Thanks for the schooling once again, but as of today my Cannondaling days are numbered. My fab shop guy just offered me a trade to finish restoring my jeep. So being the economy that it is and I am no longer employed she will have a new home. She runs just fine, maybe his son will join your forums and fall in love with the Dale just as I did. I will seriously miss my Speed 440 but a jeep can get me to work.
Peace out and long live American Muscle!!!!!!

peterock · #17 Post by **peterock** » Thu Jul 02, 2009 8:24 pm

I was originally looking at the valves as being +2mm oversized as that is what the original post was and saying the oversized valves (which we now know they aren't) could actually be hurting the performance. Not intended to get into a big debate of the valves.

ryanclark75 · #18 Post by **ryanclark75** » Thu Jul 02, 2009 8:30 pm

QUOTE (peterock @ Jul 2 2009, 03:24 PM) <{POST_SNAPBACK}>

I was originally looking at the valves as being +2mm oversized as that is what the original post was and saying the oversized valves (which we now know they aren't) could actually be hurting the performance. Not intended to get into a big debate of the valves.

My mistake and sorry. But I should have come here in the first place for advice.