Spark Arrestor Clearance Issue
#1
Registered
Thread Starter
Join Date: Nov 2000
Location: Overland Park, KS
Posts: 295
Likes: 0
Received 0 Likes
on
0 Posts
![Default](/forums/images/icons/icon1.gif)
After having new motors built for my 33 Fountain, I have an issue with clearance under the engine hatch. The motors are Dart tall deck, Dart single plane intake, 1 inch spacer, dominator carb. When all of this is under the hatch, I have about 2 1/2 inches of clearance. I do not want to raise the hatch.
Is there a "best" arrestor that will provide enough air flow? I currently have 10" round (K&N). I can replace the current element with a 2" screen. Would it be better to replace these with a long oval cleaner to gain more flow?
If I have to add more clearance, can I raise just the area above the arrestor without using scoops?
Thanks
Is there a "best" arrestor that will provide enough air flow? I currently have 10" round (K&N). I can replace the current element with a 2" screen. Would it be better to replace these with a long oval cleaner to gain more flow?
If I have to add more clearance, can I raise just the area above the arrestor without using scoops?
Thanks
#2
Registered
![Default](/forums/images/icons/icon1.gif)
Before I got my new boat, I was having a similar problem. I was going to cut a hole in the hatch and cover it with a piece of aluminum sheet formed about an inch high. That would give me 2 inches more clearence. Under the pads it would be almost unnoticable.
#3
Platinum Member
![](https://www.offshoreonly.com/forums/images/icons/platinum_member_star.gif)
![Default](/forums/images/icons/icon1.gif)
Lose the 1" spacer.
Stick with a 10" round, but go to the tallest you can fit. 2" of space from the base to the top is awful thin to make a smooth turn into a dominator. You'll lose more from the arrestor than you make with the spacer.
The perimeter area isn't your issue - it's the turn from horizontal into the vertical carb throats.
You can do what Patri suggests, and gain 3/4 to 2 more inches.
Stick with a 10" round, but go to the tallest you can fit. 2" of space from the base to the top is awful thin to make a smooth turn into a dominator. You'll lose more from the arrestor than you make with the spacer.
The perimeter area isn't your issue - it's the turn from horizontal into the vertical carb throats.
You can do what Patri suggests, and gain 3/4 to 2 more inches.
#4
Platinum Member
![](https://www.offshoreonly.com/forums/images/icons/platinum_member_star.gif)
![Default](/forums/images/icons/icon1.gif)
My buddy has a clearance issue on a 550" Hemi in a B-body Chrysler.
He ended up needing 1 3/4" tall filters. He is running dual 700's on a crossram. Dyno numbers were 914hp open carbs. 825hp with air filters on it. He added the K&N filtered "lids" instead of the top plate and went back to 880hp. This is a 1 3/4" tall filter on EACH 700 carb. You are trying only 2" on a DOMINATOR. Go for some more arrestor height.
He ended up needing 1 3/4" tall filters. He is running dual 700's on a crossram. Dyno numbers were 914hp open carbs. 825hp with air filters on it. He added the K&N filtered "lids" instead of the top plate and went back to 880hp. This is a 1 3/4" tall filter on EACH 700 carb. You are trying only 2" on a DOMINATOR. Go for some more arrestor height.
#5
Registered
Thread Starter
Join Date: Nov 2000
Location: Overland Park, KS
Posts: 295
Likes: 0
Received 0 Likes
on
0 Posts
![Default](/forums/images/icons/icon1.gif)
I asked the builder about the spacer and why it was added. He went into a fairly lengthy explanation as to why it is there (he doesn't have short answers for anything). The answer I took away from him was that the engine was designed with a set of components to meet specific objectives.
The carbs were sent to Nickerson for rebuilding and tuning. They came back $1600 later and Dean recommended that the 1 inch spacers be part of the assembled package. We did not know there was a clearance issue at the time or we would have told Dean to flow the carbs without the spacer. I think part of my height problem is also related to the drives. The boat has #3 drives that sit very high. I believe this also raises the entire package.
So if I go with a "filtered" lid, cut a hole and install an aluminum plate in the hatch, I can probably get 3 1/2 inches of arrestor height. Is that enough air flow to make the motors run the way they were designed?
Thanks for all the feedback.
The carbs were sent to Nickerson for rebuilding and tuning. They came back $1600 later and Dean recommended that the 1 inch spacers be part of the assembled package. We did not know there was a clearance issue at the time or we would have told Dean to flow the carbs without the spacer. I think part of my height problem is also related to the drives. The boat has #3 drives that sit very high. I believe this also raises the entire package.
So if I go with a "filtered" lid, cut a hole and install an aluminum plate in the hatch, I can probably get 3 1/2 inches of arrestor height. Is that enough air flow to make the motors run the way they were designed?
Thanks for all the feedback.
#6
Charter Member
![](https://www.offshoreonly.com/forums/images/icons/charter_member_star.gif)
Join Date: Oct 2000
Location: Lake Orion, MI. USA
Posts: 1,560
Likes: 0
Received 0 Likes
on
0 Posts
![Default](/forums/images/icons/icon1.gif)
I have these boxes on my PQ They give you a couple inches. I think CP Performance sells them. Not sure about you application but these may work.
__________________
Ray
Ray