Originally Posted by james bond

Hi Brownie, I have just spoken to the Ciggarette factory and they said Your THE guy to call, he said you may have some knowledge on fitting a single motor in something like a boat the size of a Gladiator, can you advise me, simon from the UK,Many Thank's.

Originally Posted by RT930turbo

Hey 007... you may want to start a new thread in the general discussion area about your project.

Originally Posted by Raylar

I am not responding to this thread as a pro or con on HI-Tek marine SS manifolds as I have no expierence with them from a performance gain or reliability standpoint.
The reason for my post here is just pretty much meant to be educational.
I have been trying for many years now to get performance boaters to understand and try and distinguish the differences between marine exhaust manifolds, their variations and true marine longer runner headers. In my performance expierence and years I try to let boaters know as an engine builder that there is a definite difference between marine manifolds and marine headers. When discussing normally aspirated marine engines, there are always usually net power gain benefits form changing either log type marine manifolds or short runner base manifold and riser type manifold exhaust pieces over to longer runner, merge collector tuned marine headers.
Even with small cubic inch smaller horsepower marine engines (250HP and 400Hp) you can see and measure generally about 10-30HP gains and associated torque increases when real longer tube true headers are used to replace original stock marine manifolds. In higher horsepower bigger cubic inch engines the increases can grow to 40-50HP form a real long tube header. Generally when stock center riser marine exhaust manifolds are replaced with true headers and not just another aftermarket marine manifold system the gains will be about 20-40HP.
Why do I say minimum? Its because with most recreational performance boats it takes somewhere between 12-25HP to net a 1 mph gain in actual boat speed and overall performance. This means a +20HP increase from any new exhaust header maqy only result in a 1-1.5mph increase in speed and thats only if all other prop, bottom and setups on the boat are spot on and correct.
We therefore get to the old addage"Bang for the Buck" .When you consider the real verified power increases from good real marine header system changes need to be measured against the costs that generally vary between $2500 and $5000 per engine for the headers only and not installation costs.
What I am also saying here is that you are not going to unbolt some of the current good design stock marine exhaust manifolds and bolt on a new marine manifold system like this design from Hi-Tek (short runner incorporated into a simple riser) or short E-top type headers or just marine replacement aftermarket manifold systems and see any real usuable net power increase.
If you are doing so for the look (BLING) and sound of the the new manifold or shorty header type polished pices then thats another story and cost justification to be considered.
If your stock manifolds are at end of life or damaged then the aftermarket manifolds will in many cases be at equal or sometimes lower cost than the OEM manifold and riser replacements. It is also advisable and a benefit for reliability to replace these exhaust manifolds with the new dry riser joint type manifolds and eliminate the wet water passage and gasket joints between the base manifold and riser where engine destroying leaks and corrosion can and do occur.
In summary here, don't expect most replacement short runner single riser manifold systems to add any real measurable power on stock engines and even on higher horsepower 400-500HP marine engines the gains may only be in the 15-20HP range which will net a very small or almost unmeasurable increase in boat performance.
Bottom line- Don't call marine short runner manifolds HEADERS! and when considering replacing exhaust systems on your boats try to find test data and actual performance boater results form independant sources and don't rely on manufacturers or distributor claims to make your $2500-$5000 exhaust system expenditures if you work on a budget and expect measurable results for the purchase!
I will receive a lot of flack for this post from varing sources and a lot of so called marine exhaust experts, but I have done a great deal of independant testing and evaluation on marine exhaust upgrades on V-8 marine engines between 300-700 HP in general as have others on OSO like Bob at Full Throttle and and many good marine engine builders. Most of us will say that a good true header or header manifold system will add some good measurable power increases. Do exhaust upgrades always translate to increased boat performance, Heck NO! That increase will depend on many variables and that's a choice for you as the boat owner and money supplier to make and substantiate.
Please also remember that all the other factors of hull form, type,size, weight, setup and drive and prop efficiences will also greatly affect the performance gains seen from exhaust upgrades.
Investigate header and manifold exhaust systems carefully and determine what you will accept and need in performance gains, then buy and spend accordingly.

Best Regards,
Ray @ Raylar

Originally Posted by Raylar

I am not responding to this thread as a pro or con on HI-Tek marine SS manifolds a s I have no expierence with them from a performance gain or reliability standpoint.
The reason for my post here is just pretty much meant to be educational.
I have been trying for many years now to get performance boaters to understand and try and distinguish the differences between marine exhaust manifolds, their variations and true marine longer runner headers. In my performance expierence and years I try to let boaters know as an engine builder that there is a definite difference between marine manifolds and marine headers. When discussing normally aspirated marine engines, there are always usually net power gain benefits form changing either log type marine manifolds or short runner base manifold and riser type manifold exhaust pieces over to longer runner, merge collector tuned marine headers.
Even with small cubic inch smaller horsepower marine engines (250HP and 400Hp) you can see and measure generally about 10-30HP gains and associated torque increases when real longer tube true headers are used to replace original stock marine manifolds. In higher horsepower bigger cubic inch engines the increases can grow to 40-50HP form a real long tube header. Generally when stock center riser marine exhaust manifolds are replaced with true headers and not just another aftermarket marine manifold system the gains will be about 20-40HP.
Why do I say minimum? Its because with most recreational performance boats it takes somewhere between 12-25HP to net a 1 mph gain in actual boat speed and overall performance. This means a +20HP increase from any new exhaust header maqy only result in a 1-1.5mph increase in speed and thats only if all other prop, bottom and setups on the boat are spot on and correct.
We therefore get to the old addage"Bang for the Buck" .When you consider the real verified power increases from good real marine header system changes need to be measured against the costs that generally vary between $2500 and $5000 per engine for the headers only and not installation costs.
What I am also saying here is that you are not going to unbolt some of the current good design stock marine exhaust manifolds and bolt on a new marine manifold system like this design from Hi-Tek (short runner incorporated into a simple riser) or short E-top type headers or just marine replacement aftermarket manifold systems and see any real usuable net power increase.
If you are doing so for the look (BLING) and sound of the the new manifold or shorty header type polished pices then thats another story and cost justification to be considered.
If your stock manifolds are at end of life or damaged then the aftermarket manifolds will in many cases be at equal or sometimes lower cost than the OEM manifold and riser replacements. It is also advisable and a benefit for reliability to replace these exhaust manifolds with the new dry riser joint type manifolds and eliminate the wet water passage and gasket joints between the base manifold and riser where engine destroying leaks and corrosion can and do occur.
In summary here, don't expect most replacement short runner single riser manifold systems to add any real measurable power on stock engines and even on higher horsepower 400-500HP marine engines the gains may only be in the 15-20HP range which will net a very small or almost unmeasurable increase in boat performance.
Bottom line- Don't call marine short runner manifolds HEADERS! and when considering replacing exhaust systems on your boats try to find test data and actual performance boater results form independant sources and don't rely on manufacturers or distributor claims to make your $2500-$5000 exhaust system expenditures if you work on a budget and expect measurable results for the purchase!
I will receive a lot of flack for this post from varing sources and a lot of so called marine exhaust experts, but I have done a great deal of independant testing and evaluation on marine exhaust upgrades on V-8 marine engines between 300-700 HP in general as have others on OSO like Bob at Full Throttle and and many good marine engine builders. Most of us will say that a good true header or header manifold system will add some good measurable power increases. Do exhaust upgrades always translate to increased boat performance, Heck NO! That increase will depend on many variables and that's a choice for you as the boat owner and money supplier to make and substantiate.
Please also remember that all the other factors of hull form, type,size, weight, setup and drive and prop efficiences will also greatly affect the performance gains seen from exhaust upgrades.
Investigate header and manifold exhaust systems carefully and determine what you will accept and need in performance gains, then buy and spend accordingly.

Best Regards,
Ray @ Raylar

Originally Posted by mike tkach

good post ray,a lot of guys believe what they read in advertisements when in reality it,s bs trying to sell their products.thanks for the post.

Originally Posted by FIXX

yo mike,,look at the date,,,