Logs vs Headers

[miller19j]

Ok I have heard many different opinions on this one. Some have said that you will not see any performance gains from headers until you get above 500hp others have said that headers are the best performance bolt on upgrade you can buy.
My question is with a mildly built 454 in a jet how much performance will you see between wet headers and logs?
Thanks, Any info would be appreciated.

[MikeF]

M19, The only time that "you" really need headers (on a jet) is if you start wanting to turn more RPM. The logs will not flow more air than headers. The bigger lift or duration cam w/ close lobe centers this is even more important to run headers.
If it is a mild build, I would stick w/ the logs for safety, convenience and insurance.
Granted, the headers would give you a little more RPM and maybe 5/8 mph.
Besides, your boat looks good as is! :D

[miller19j]

Thank you!
I do not want to have to rebuild the engine hatch for headers if I do not have to.

[Jungle Boy]

MikeF:
M19, The only time that "you" really need headers (on a jet) is if you start wanting to turn more RPM. The logs will not flow more air than headers. The bigger lift or duration cam w/ close lobe centers this is even more important to run headers.
If it is a mild build, I would stick w/ the logs for safety, convenience and insurance.
Granted, the headers would give you a little more RPM and maybe 5/8 mph.
Besides, your boat looks good as is! :D If headers would give 5/8 mph, that would be the cheapest mph gain in boating. In my experience Imco's or Lightenings will give you about 100 RPM when installed with a good air filter (K&N). In Canada, insurance companies don't ask about the type of exhaust. Is that normal in the States? :cool:

[MikeF]

Maybe I was being a little overly optimistic.....basically I was trying to say it would probably not be worth the return on investment wink .

[miller19j]

I do not know if it is normal but my insurance agent wanted to know if I had thru transom exhaust. He did not really care about the HP but the Exhaust was a big deal to him.

[MikeF]

The last place I tried (progressive) did not insure O/T headers.

[grimreaper]

anyone ask these agents IF they will write a policy on a boat with OT headers that excludes any burn claims?
[ September 27, 2002, 04:28 PM: Message edited by: grimreaper ]

[MikeF]

Not yet. I will try next time.
I'm pretty sure when the person trying to help you get insurance is using the same website you can go to to try to get insurance...there will not be alot of help on that end. I think that's what happens?! :confused:

[DansBlown73Nordic]

I will be putting a set of headers on my boat Sunday. I have run logs for the last three years. I know exactly what the boat will do now. I will give you guys a report. wink

[79Hawaiian]

I suggest anyone switching to headers or already have headers and considering changing companies find out first if you can get coverage. I have come up all negatives on mine. I got an excellent quote from Progressive but did not sign. I went back 3 months later and they would not even offer me insurance due to my OT pipes. Found out most companies won't now.
What's worse: Tree hugger or lawyer?

[Omega21]

Umm..not to breakup the insurance discussion, but I have the same question about logs vs headers on my boat. I have/will have a 21' Omega DC with:
455 Olds
-425 rod/455 Pontiac pistons (11:1 or a little higher..thereabouts, 7" rod)
-Ga heads, big valve, port work
-Nodular crank
-10 qt pan, windage tray, head drain tubes to pan
-crank scraper (maybe)
-292H or 305H magnum comp cam kit(whole valvetrain)
-Haven't picked an intake or carb yet, will most likely be something like an 850 Edelbrock with a performer RPM intake (Or whatever the olds version is)
-Mallory ignition..breakerless. Don't remember what box I have, may go to a MSD box anyway.
I'm aiming at big torque under 5k rpm. Once I get the motor run on the local dyno, I'll pick the impeller. I'm thinking it'll be an A or an A2.
I've found a set of BBC TT headers I'm really interested in, but to get them to work it takes some millwork, welding and a trip to the coating shop. If I'm not going to gain anything with the headers...I guess I'll just bolt my logs back on & put silencers in the tips. Noisy pig!!
Todd

[Dennis Moore]

Great engine! With that big camshaft you had better go with headers. The problem with your setup is that Edelbrock only makes the Performer for the Olds 455 (no performer RPM). I dont think you will have a matching intake and camshaft combination. The camshafts will only work over 5000 rpm and will not produce torque like you want.
Dennis Moore

[DansBlown73Nordic]

Well I took my Stevens out with the Eagle O/T headers. It ran great. I could see 2-300 more RPM,s. I would say 3-5 mph faster. The sound was the best part!!! eek! :D I will be buying a set for my new project.