questions For the performance guru

Hey guys,
In the beginning stages of my stroker 408 build for my Fish nautique. had a few questions (and may come up with some more)
I have never built a stroker windsor before, I have had my fair share of clearancing 350 and 454 chevy stuff for big strokes. alot for street use though. never a reverse rotation ford.
anyways if anyone has any pointers for this added horsepower into these boat's drivetrains I would appreciate it.

MY main question in this thread is concentrating on exhaust though.

-What is a decent flowing manifold you guys are running? I am coming up with a lot of huge money stuff when i search. (drag boat stuff)
I plan to keep the wet exhaust and would like to minimize my chance of taking a gulp when i come off plane quickly.
the fish nautique exhaust setup is mostly under the waterline and even with good flaps on the tips i am afraid of having issues with this. In some applications I have seen a "Y" shaped exhaust fitting put inline closest to the downpipe to give that rush of water a place to go and to stop it from traveling into the risers and manifolds.
has anyone had experience with this kind of setup in these boats? recommended or not?

If you don't already have them, get some 3.5in HO risers, and I would use the flaps. You could have a much worse day than most if you sucked up some water.

Curious to know what cam your going to use? Looking at Comp Cams specs on marine cams, all variations of the SBC used the same cams so I guess the 409 may use the same cam as the 351. I haven't gotten close enough to beginning my stroker to find out for sure.

I will check out the pcm manifolds. 2k isnt in the budget at the moment for just maifolds.

Also good to know about the cam, I hadn't got that far yet and didnt think about that. I will have to make a call to my cam guy and see what he can do. I am not opposed to running LH. the velvet drive can be run in either direction from what i understand.

MrMcD wrote: Exhaust inversion is a real issue in big cam boat engines. If you use a cam with lots of overlap the engine will suck water out of the exhaust into the cylinder and cause big issues. I do not know how much overlap works and when you start getting inversion. Might check with the drag boat guys and find out what works in advance to save headaches.

All true... but the point at which reversion occurs is going to be well beyond any sane build for such a large and heavy boat, unless someone makes a real bonehead selection. We have guys here running cams in the .560+ lift range on their 351w based engines without issue, and we're a ways north of that on our BBC. Of course, talking with a marine cam expert if going wild should help keep you safe. At a minimum, run any cam selection considerations by us here and we'll provide some feedback.

True, LSA and duration are the keys. Just throwing a few nowhere-near-stock cam numbers out there to show that you can go a lot warmer without reversion concerns.

This is why I love this site. And forums in general.
I haven't sat down and put together a parts list for this build yet. It was literally decided it was a go about a week ago after about a month of reading builds on the intraweb. (It was either stroke the ford or bolt in a Big Chevy)
I'm thinking once I get my list together I'll start a new thread and see what everyone has to say.

During my research I came across a stroker build on this site I believe, but when I do a search now i can't seem to find it. It may have been on another forum. Anyone know what I'm talking about?

Thanks thats the one. I dont know why i couldnt find it again. I have to spend a little time and read that article.

Back to the manifolds and riser options, i have found these which sound pretty good. I cant find any reviews on people using them though.
http://www.cpperformance.com/p-13919-small-block-ford-with-aluminum-riser.aspx

With my hp goals being pretty small in comparison to most stroker builds i wonder how much of a gain these indmar manifolds would be over my current osco setup which is in good shape. In the name of progress i could always bolt those up and run them till i feel its worth spending the money on better ones.

There is always these
http://www.cpperformance.com/p-14932-pcm-351-ford-replacement-exhaust-manifolds-3-12-hose.aspx

I would not expect the internal geometry of those aluminum Indmars to be any better than the stock PCM's. They're just another stock manifold. If you're going to be running in salt, aluminum is going in the wrong direction. The second option you linked are the Hiteks I mentioned previously. Joe and I (and a few others here) have a set and they're nice, but pricey. If you have budget concerns, money would be better spent elsewhere. Especially if you're going to remain at or below the 1hp/ci mark.

after all the unknowns i may be running into building a stroker, the 454 does hold its ground.
I'm going to start a separate thread and get some opinions because the whole reason i posted to begin with is to get opinions and help. i feel like the decision (454 or stroker) is one that has so many pros and cons.
the thing about availability of exhaust manifolds is just ONE of the cons i am finding out.

DayTony wrote: Also salt water does not go through the maifolds themselves, it is completly fresh water cooled. the raw water pump mixes in at the elbow in my current setup and i prefer to keep it that way.

I would be really interested in knowing how this is set up. Normally a closed cooling system only cools the block. The RWP still would cool the manifolds and risers/elbows.
How are the manifolds and risers/elbows being isolated by two seperate cooling systems?

DayTony wrote: backfoot100 wrote: DayTony wrote: Also salt water does not go through the maifolds themselves, it is completly fresh water cooled. the raw water pump mixes in at the elbow in my current setup and i prefer to keep it that way. I would be really interested in knowing how this is set up. Normally a closed cooling system only cools the block. The RWP still would cool the manifolds and risers/elbows. How are the manifolds and risers/elbows being isolated by two seperate cooling systems? This is pretty common actually, it preserves the life of the manifold greatly when used in saltwater. There is a stainless block off plate where the riser bolts to the manifold and the raw water mixes either at the elbow or in said riser, depending on the setups. mine actually mixes in the riser itself. not sure one the flow pattern though I have to go shovel my decks off today I will take not of the flow pattern while i'm out there and report back.

Interesting. That would be cool if you did that.
It certainly makes sense and would definitely improve the life of the manifold, however the manifold would still be running considerably warmer than any open cooled system. Without circulating water I have to believe that they would still get pretty hot before the thermostat opens up. Or is there some other way the water is being circulated through the manifolds until the thermostat does open?
Just curious and all.

it is absolutely a pile of hoses.
i just was out there and the RWP pushes through the heat exchanger and into the riser and out the elbow where it mixes into the exhaust. pretty standard.
the other pump draws coolant out of the exchanger and into block then there is a T on top of the tstat housing, goes into the front of the manifolds, comes out the back and up into the exchanger.

backfoot100 wrote: Good info, thanks guys. I just assumed the RWP still cooled the manifolds and risers. You know what happens when you assume?

There are actually two options to go with fresh water cooling. The more complex system does include the exhaust manifolds. Yes, more hoses plus a much larger tube in shell heat exchanger to handle the extra BTU load. The complete fresh water get pretty pricey and complicated. Most will just go with an exhaust manifold change every 5 years or so.

I've been looking for a way to put a O2 sensor into the riser, and thanks to a little confusion by Eddie I think if found I'm looking for as well as some more answers to his question. If you look up the Osco manifolds for an Indmar Ford motor they have an extender with a spot in the casting for a hose fitting that goes between the manifold and the riser. The gasket set that includes a plate to block the water in the off between the 2 pieces. The factory PCM fresh water system only does the motor so their manifolds don't have the spots to hook the hoses to for the different hose routing.