Help with Bad Bad Boat
April 13th, 2010, 05:48 PM
#1
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Join Date: Apr 2010
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Help with Bad Bad Boat
Hi Folks!!
I ran across your forum researching upgrades for my 350 jet boat engine. I would love to hear from anyone using Dynosim5-pro for engine design. I’m using this for cam and other part comparisons. I would also like to talk with anyone using Edelbrock or big block heads on the small block. Before you guys waste your time telling me stuff I already know, I’ll give you a rundown on what I have. I made a mistake with the cam selection and it is not the best available according to the computer.
1970 Olds 350 355.4 CID, F1 block decked to .013, 1970 N crank std, stock rods, Speedpro flat tops, all oil mods {oil restrictors and restricted pushrods}, Stock 8 heads 78.2CC 1.879 1.622 valves, Comp roller rockers fully adjustable, Edelbrock performer manifold, Hardin Marine through hull exhaust {no headers} Holley 4150 750CFM. Crower 56903 cam straight up 289/300 214/224@.050 .475 .498 lift 112LCA 108 ICL{very close to the Edel RPM Cam}. Compression is 9.03 Quench distance is .052
According to the HP curve for the jet pump the engine is delivering about 270 HP and tops out at 4350 RPM. The curve does not account for torque and the limited RPM is probably due to the torque curve dropping off. I would like to use the Edelbrock Heads for a couple of reasons, reduced weight, eliminate buying bigger valves and the cost of head porting, no cross over port filling. I’m already using an electric fuel pump and know about the clearance problem. I hope doing this upgrade will yield the following.
RPM Heads reduced to 76CC 9.54 Compression, quench distance .041, Edel 7111 Manifold port matched, tweak the Holly, Comp Cams XE274H 274/289 230/236@.050 .520 .523 Lift 110 LCA{LS} 106 ICL{Intake Centerline}
The Computer says 369HP@5000 434Ft@3500 with a very nice torque curve from 2500 to 4500 rpm. This “I hope” will push the boat into the 70 miles per hour never never land area. I’m currently in the 60 MPH wannabe area. The biggest problem with this engine is the limited Exhaust options. The wet exhaust is very large {2-½ inch} but probably will not provide any scavenge effects. This is reflected by the computer numbers, which you guys may find low for this configuration. I’m a little concerned about the piston to valve clearance with the E heads. I read that the stock valve angle is 6 degrees and know the Ebrock is 18.
Hope I didn’t bore you all to tears, any comments would be welcome {wish I dumped all this cash in a BB}
Thanks airmale
I ran across your forum researching upgrades for my 350 jet boat engine. I would love to hear from anyone using Dynosim5-pro for engine design. I’m using this for cam and other part comparisons. I would also like to talk with anyone using Edelbrock or big block heads on the small block. Before you guys waste your time telling me stuff I already know, I’ll give you a rundown on what I have. I made a mistake with the cam selection and it is not the best available according to the computer.
1970 Olds 350 355.4 CID, F1 block decked to .013, 1970 N crank std, stock rods, Speedpro flat tops, all oil mods {oil restrictors and restricted pushrods}, Stock 8 heads 78.2CC 1.879 1.622 valves, Comp roller rockers fully adjustable, Edelbrock performer manifold, Hardin Marine through hull exhaust {no headers} Holley 4150 750CFM. Crower 56903 cam straight up 289/300 214/224@.050 .475 .498 lift 112LCA 108 ICL{very close to the Edel RPM Cam}. Compression is 9.03 Quench distance is .052
According to the HP curve for the jet pump the engine is delivering about 270 HP and tops out at 4350 RPM. The curve does not account for torque and the limited RPM is probably due to the torque curve dropping off. I would like to use the Edelbrock Heads for a couple of reasons, reduced weight, eliminate buying bigger valves and the cost of head porting, no cross over port filling. I’m already using an electric fuel pump and know about the clearance problem. I hope doing this upgrade will yield the following.
RPM Heads reduced to 76CC 9.54 Compression, quench distance .041, Edel 7111 Manifold port matched, tweak the Holly, Comp Cams XE274H 274/289 230/236@.050 .520 .523 Lift 110 LCA{LS} 106 ICL{Intake Centerline}
The Computer says 369HP@5000 434Ft@3500 with a very nice torque curve from 2500 to 4500 rpm. This “I hope” will push the boat into the 70 miles per hour never never land area. I’m currently in the 60 MPH wannabe area. The biggest problem with this engine is the limited Exhaust options. The wet exhaust is very large {2-½ inch} but probably will not provide any scavenge effects. This is reflected by the computer numbers, which you guys may find low for this configuration. I’m a little concerned about the piston to valve clearance with the E heads. I read that the stock valve angle is 6 degrees and know the Ebrock is 18.
Hope I didn’t bore you all to tears, any comments would be welcome {wish I dumped all this cash in a BB}
Thanks airmale
April 17th, 2010, 02:36 PM
#2
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Join Date: Mar 2008
Location: Phx, AZ
Posts: 1,012
OMG, does that look like fun.
I have run BBO heads on a small block, and they sure love the added airflow, just need to cut them some for compression.
You really seem to be looking for some top end horsepower.
Now what is the deal with the E heads, you only make a short mention of these at the end of your post. What valves, any milling, port work?
I would start by adding airflow, even though the cam is small. Changing cams will most definitely require you to change impellers.
I would not just jump into a set of Edelbrocks, try out the E heads if they are fresh.
JMHO
Jim
I have run BBO heads on a small block, and they sure love the added airflow, just need to cut them some for compression.
You really seem to be looking for some top end horsepower.
Now what is the deal with the E heads, you only make a short mention of these at the end of your post. What valves, any milling, port work?
I would start by adding airflow, even though the cam is small. Changing cams will most definitely require you to change impellers.
I would not just jump into a set of Edelbrocks, try out the E heads if they are fresh.
JMHO
Jim
April 17th, 2010, 08:17 PM
#3
He has stock #8 heads now and wants to go to E-heads(Edelbrock)
Sounds like your combo will work just fine. You will need to get 3/8 push rods for the E-heads come with 3/8 guide plates. Or you can change the guide plates to 5/16 and use 5/16 push rods. At any rate you will need harden push rods.
I used Ford small block roller rocker arms on my E-brock heads, some say not a good idea, but it has only been 10 years with them, so far so good.
If you are going this far, you might want to get the over the transom headers.
Good luck,
Gene
Sounds like your combo will work just fine. You will need to get 3/8 push rods for the E-heads come with 3/8 guide plates. Or you can change the guide plates to 5/16 and use 5/16 push rods. At any rate you will need harden push rods.
I used Ford small block roller rocker arms on my E-brock heads, some say not a good idea, but it has only been 10 years with them, so far so good.
If you are going this far, you might want to get the over the transom headers.
Good luck,
Gene
April 17th, 2010, 10:11 PM
#4
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Join Date: Apr 2010
Posts: 10
Hi Guys thanks for taking the time to respond
I was considering the Edelbrocks mostly for the weight savings. If I lose the iron heads and wet exhaust logs the weight is near 100lbs. Weight is the cheapest way to go faster in a boat. I intended to use the heads stock except for milling to 76CC for 9.5 compression until I see how they perform. I was concerned that too much port flow may slow down velocity due to the smaller bore of the 350. The heads were designed mostly for the 455 and info from guys using them is welcome. I’m using DynaSim5 to run comparisons with flow numbers I found on the net. I’ve read other posts here about porting the different heads and you guys are right on target. The small block heads will easily flow just as well as stock Edelbrocks. My 8 heads "ported" tested just as good with 1.875 and 1.622 valves if the flow numbers I used are accurate. If I get the Ebrocks I will lose the weight, won’t have to buy valves and springs or port. If I don’t get the performance want I can always work the Ebrocks later. I’m still on the fence about the cam and am running numbers on everything.
I’ve read a lot of folks are running compressions in the 10:1 range on pump gas, you guys think this will help velocity? What are you running?
Gene, The arms are a great Idea, I’ll be checking that out. If that’s your Cutlass I’m in love with it “Soooo Hot” My hat off to ya, Please post a link so I can check it out. On board with the push rods, gotta go with 5/16 for now as I already have the setup with the 8 heads. I should be able to use my Comp guide plates.
I was considering the Edelbrocks mostly for the weight savings. If I lose the iron heads and wet exhaust logs the weight is near 100lbs. Weight is the cheapest way to go faster in a boat. I intended to use the heads stock except for milling to 76CC for 9.5 compression until I see how they perform. I was concerned that too much port flow may slow down velocity due to the smaller bore of the 350. The heads were designed mostly for the 455 and info from guys using them is welcome. I’m using DynaSim5 to run comparisons with flow numbers I found on the net. I’ve read other posts here about porting the different heads and you guys are right on target. The small block heads will easily flow just as well as stock Edelbrocks. My 8 heads "ported" tested just as good with 1.875 and 1.622 valves if the flow numbers I used are accurate. If I get the Ebrocks I will lose the weight, won’t have to buy valves and springs or port. If I don’t get the performance want I can always work the Ebrocks later. I’m still on the fence about the cam and am running numbers on everything.
I’ve read a lot of folks are running compressions in the 10:1 range on pump gas, you guys think this will help velocity? What are you running?
Gene, The arms are a great Idea, I’ll be checking that out. If that’s your Cutlass I’m in love with it “Soooo Hot” My hat off to ya, Please post a link so I can check it out. On board with the push rods, gotta go with 5/16 for now as I already have the setup with the 8 heads. I should be able to use my Comp guide plates.
April 18th, 2010, 06:37 AM
#5
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Join Date: Mar 2008
Location: Phx, AZ
Posts: 1,012
He has stock #8 heads now and wants to go to E-heads(Edelbrock)
1970 iron BBO castings will always be "E" heads to me.
Are you saying that your #8's flow over 240 cfm on the intake side?
That blueish pile under the hood of my tag pic, is a "E" headed, 350. The heads flow 206@ .500 lift, with a 1.995 intake. It wont smoulder the tires (I would rather it would not), but it sure does run better than the ported #5 heads ever could.
Good luck.
Jim
Last edited by Warhead; April 18th, 2010 at 07:26 AM. Reason: Do I need to???
April 18th, 2010, 08:32 AM
#6
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Join Date: Apr 2010
Posts: 10
Oops!!!
I was incorrect about the valve sizes, here are the numbers I’m using and I will let you judge for yourselves. The HP and torque figures produced by the computer suggest that the stock C, stock Ebrock, and the “ported” 8 heads make very close to the same power but I’m sure you guys already know that. The Ebrock flow number came from Ebrock and the rest from this link. http://www.oldsmobility.com/!in-progress/Olds-heads.htm I have no way of knowing the level of porting on the 8’s or if any of this info is accurate. I’m using it only for baseline comparisons. I’m glade to hear that some of you guys are having success using BB heads on the SB.
“I hope the link works”, some opinions on this info would be great.
I was incorrect about the valve sizes, here are the numbers I’m using and I will let you judge for yourselves. The HP and torque figures produced by the computer suggest that the stock C, stock Ebrock, and the “ported” 8 heads make very close to the same power but I’m sure you guys already know that. The Ebrock flow number came from Ebrock and the rest from this link. http://www.oldsmobility.com/!in-progress/Olds-heads.htm I have no way of knowing the level of porting on the 8’s or if any of this info is accurate. I’m using it only for baseline comparisons. I’m glade to hear that some of you guys are having success using BB heads on the SB.
“I hope the link works”, some opinions on this info would be great.
April 18th, 2010, 05:58 PM
#7
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Join Date: Mar 2008
Location: Phx, AZ
Posts: 1,012
I hate to be the bearer of bad news, and even though what I am going to say may upset a few, I would rather be honest, rather than fluff people up.
Delete that site from your bookmarks.
Those figures are inflated by 20- 25%.
This is a big blistered FACT.
Joe Mondello published the #6 head with small valves, flows 185 cfm on the intake side. He also said the #5's flow 200 @ .650 lift which I find a little rich, unless they were ported.
All of these numbers plugged into your computer program has obviously not been paralleled by the performance of your boat. I do not like these programs for a number of reasons. But if you were to plug 185 cfm into it, I bet you would be CLOSER to what it is really doing at this point.
I think you are onto the right track to a rightously fast boat. I, for one, would like to see how well you do with this small block, so keep us posted.
BTW, most people who have removed large valve C heads, and put stock Edelbrocks on, claim around 100 more hp on a 455.
Jim
Delete that site from your bookmarks.
Those figures are inflated by 20- 25%.
This is a big blistered FACT.
Joe Mondello published the #6 head with small valves, flows 185 cfm on the intake side. He also said the #5's flow 200 @ .650 lift which I find a little rich, unless they were ported.
All of these numbers plugged into your computer program has obviously not been paralleled by the performance of your boat. I do not like these programs for a number of reasons. But if you were to plug 185 cfm into it, I bet you would be CLOSER to what it is really doing at this point.
I think you are onto the right track to a rightously fast boat. I, for one, would like to see how well you do with this small block, so keep us posted.
BTW, most people who have removed large valve C heads, and put stock Edelbrocks on, claim around 100 more hp on a 455.
Jim
Last edited by Warhead; April 18th, 2010 at 06:01 PM.
April 19th, 2010, 09:19 AM
#8
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Join Date: Apr 2010
Posts: 10
Jim,
You’re right about the computer; it’s only as good as the info that goes into it. As far as its value goes I’ll relate a story to you. I was looking for a new machinist because the guy that did my block was a screw up (example, I told him to deck the block to .005 and got .013} I walked into another local shop that does HP engine work and is equipped with a flow bench and dyno, they had 6 guys on the job and I was talking to the owner. These guys do everything from heavy industrial to VVT 4 valve rice burners. The boss was asking me some questions about what I had and what I was looking for while punching numbers into his desktop. I could see his monitor and he was using the same computer program I am. You’re correct if you’re suggesting that there’s no substitute for experience and that’s why am picking your brains but feel the computer is a great way to help separate fact from the fiction and is valuable as a starting point.
You are also correct that I’m down in HP from what the computer says I should have. This bugged the heck out of me so I started checking. The original program I used to design this engine was an old one {2000} and not able to plot the ignition advance curve. The new version I use does and when I plugged in the numbers I found 22HP that I’m missing out of about 30. The rest of the missing HP is due to the unique problem with a jet boat cooling system, “The engine runs too cold” this is because the engine uses water from the jet pump and not a conventional water pump. Don’t hold me to these numbers guys I don’t have my build sheet in front of me for this post and the missing HP is based on the Berkeley HP curve, this does not account for torque and I have no idea how accurate it is. The end result is that the computer said I got what I have within about 2%.
We all know there’s a lot of BS out there and too much of it comes from part manufacturers that just want to sell parts. An example of this is I’ve run every cam made for the 350and 455 and found only 2 that deliver the best HP and torque numbers for this application {mild performance build for Max HP and torque from 3000 to 5500 RPM}. These are the Comp Cams XE268H and the XE274H. Anybody running these cams? If anyone has reliable head flow numbers this would help a lot.
airmale
You’re right about the computer; it’s only as good as the info that goes into it. As far as its value goes I’ll relate a story to you. I was looking for a new machinist because the guy that did my block was a screw up (example, I told him to deck the block to .005 and got .013} I walked into another local shop that does HP engine work and is equipped with a flow bench and dyno, they had 6 guys on the job and I was talking to the owner. These guys do everything from heavy industrial to VVT 4 valve rice burners. The boss was asking me some questions about what I had and what I was looking for while punching numbers into his desktop. I could see his monitor and he was using the same computer program I am. You’re correct if you’re suggesting that there’s no substitute for experience and that’s why am picking your brains but feel the computer is a great way to help separate fact from the fiction and is valuable as a starting point.
You are also correct that I’m down in HP from what the computer says I should have. This bugged the heck out of me so I started checking. The original program I used to design this engine was an old one {2000} and not able to plot the ignition advance curve. The new version I use does and when I plugged in the numbers I found 22HP that I’m missing out of about 30. The rest of the missing HP is due to the unique problem with a jet boat cooling system, “The engine runs too cold” this is because the engine uses water from the jet pump and not a conventional water pump. Don’t hold me to these numbers guys I don’t have my build sheet in front of me for this post and the missing HP is based on the Berkeley HP curve, this does not account for torque and I have no idea how accurate it is. The end result is that the computer said I got what I have within about 2%.
We all know there’s a lot of BS out there and too much of it comes from part manufacturers that just want to sell parts. An example of this is I’ve run every cam made for the 350and 455 and found only 2 that deliver the best HP and torque numbers for this application {mild performance build for Max HP and torque from 3000 to 5500 RPM}. These are the Comp Cams XE268H and the XE274H. Anybody running these cams? If anyone has reliable head flow numbers this would help a lot.
airmale
November 12th, 2013, 07:20 PM
#9
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Join Date: Apr 2010
Posts: 10
Bad Boat
http://www.flickr.com/photos/107208207@N03/10708010695/ Video LinkWell guys here’s an old project that a few of you were interested in hearing about when finished. Sorry I haven’t been on the site for so long but I don’t have to tell you how “life” can get in the way of the fun projects we love to play with.
I’d like to thank the administrator for sending me a happy Birthday email, which is a nice touch and reminded me that I needed to put this stuff together to possibly contribute to our members.
The project was designing and building an Olds small bock using Edelbrock 455 heads for a boat. I’ve posted on the end of the old thread and have enclosed a link to a short video with a couple of pics and the build sheet. I included a couple of screen shots of the computer program I used and will leave it to those interested to check this stuff out and give opinions or ask questions.
Thanks to all how responded to the thread and everyone else how helps make this a great site. airmale
November 13th, 2013, 11:15 AM
#11
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Join Date: Apr 2010
Posts: 10
Bad Boat
I gotta say I’m very pleased with the engine and performance but if I had it to do over I would have invested in a BB. The boat handles beautifully as the hull was designed by Ken Baker who built race boat hulls in the late 60’s. The sound of the engine is incredible and turns heads wherever it goes. I didn’t reach 70 but with a light load I can get to 65 and out perform 90% of the other boats on the river. If you caught the video, {link at top of last post} the guy at the boat launch walked over and asked. “What the hell have you got in that” after I fired her up. Stuff like that makes me forget all the time and money spent. I need to explore other factors that may keep me from a higher speed such as the condition to the bottom {rough} and I don’t have a “Place Diverter” that would allow me to trim the boat. Working on those may get me to 70. I’ll try to upload an audio file so you can hear the idle.
Thanks for the thumbs up airmale
Thanks for the thumbs up airmale
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