Wette Vette,
A customer is dynoing a "head/cam/intake/spacer" package on another board. The cam is base on the cylinder head flow with a 2" pipe. He is going to dyno the engine with dyno headers, CMI's, and a pair of lightnings. Marine stuff will have the water running through them. Should have some real world stuff on this in a day or 2.

Chris

Testing:
Still some issues to work out but "tenative" testing shows a decrease of 35 to 40#/ft of torque average when switching from dry performance headers to marine wet manifold exhaust type. Due to some fuel issues testing is not complete but should have some more info soon.

Chris

Thanks for the data, Chris. Is the loss across the board or do the manifolds work up to a point then fall behind?

Where did max HP/TQ occur between the two? How much did the carb jetting change?

Does anyone have part numbers for recommended cams on this thread? (Other than the Crane cams listed.) If you are selling cams based on your knowledge PM me. I would like to discuss with you. I am buying the same heads as WAGS382 to install on 1998 500 HPs. Thanks, Tom

Thunderstruck,
If I can be of help you can call me at 423 854 0007. I'll try to answer any questions. Also RM Builder, Bob is well qualified.

Chris

Chris, Thanks for your time today. The discussion answered a lot of questions. If you are in need of cam help I highly recommend calling csstraub. I learned A LOT.

Thunderstruck

BTW I would love to publish a synopsis of what we discussed today if: 1. I could remember, it was like trying to drink with a fire hose. 2. I could completely understand what was being relayed to me.

I did learn one thing, after this discussion, I see there is a LOT to cam selection and I have finally reached the realm of being consciously incompetent, i.e. I don't know what I'm doing but at least I know what I don't know. Believe me, if you are a casual mechanic as I am, there is a huge body of knowledge that these guys have that I will not be able to get looking at this thread. I will pay the money and leave it to the experts.

Tom

I totally agree Thunderstruck! What is really fun and confusing is how different cam designers come up with a wide variation of designs for the same exact application. I have worked with Erson, Cam Motion and Comp to name a few and gave all of them the same exact engine data required for them to give me a cam recommendation. Not really surprised when their recommendations were all quite a bit different. I have found the best way to get the correct cam is to talk to engine builders that are building engines similar to what you are after. I went with Nickerson and got the heads, cam, carb and intake from him. He has built a few motors with the exact combo I bought from him and has had great results with HP in the neighborhood of where I wanted to be. The solid roller cam he sold me was again different from the recommendations I got from the cam guys, but at least I knew it wasn't a one-off experiment. You are on the right track working with a builder who has probably built motors similar to what you are after!! Good luck,

Craig

I agree with what Craig said about working with someone. . .to add to that, most seem to get a dozen of oppinions. . . human nature does this as we seek security that we are doing the right thing. I tell people to align yourself with a mentor that you trust and go with what they tell you. Most will give you options and these options are all towards a certain goal. Getting 5 other people envolved is not productive.

Tom, you welcome. Sometimes I ramble and if I did I apologize. Camshafts. . . brain of the engine. I approach them this way: We don't race flow figures but without knowing or asking how much air is coming into and out of an engine, you can not design/recommend/or grind something that controls this for a CID that runs in a certain rpm range.

Update: Dyno test on the 502 should be done late this week. Fuel problem is diagnosed and now awaiting parts to fix it.

Chris