small block question heads/cam combo
#1
Gold Member
Gold Member
Thread Starter
Join Date: Oct 2005
Location: Olmsted Falls,Ohio Marblehead,Oh
Posts: 11,635
Likes: 0
Received 204 Likes
on
132 Posts
small block question heads/cam combo
I just did heads and cam on my boat,I have mixed feelings about the results,you guys seem like you know about small blocks,I would love to get opinions here.
For now I reused my short block,280 hrs,very well kept and clean,I have dart sportsmanII heads with 64 cc chambers,cam is crane 114 lca 212/[email protected] with.446/.459 lift with an edelbrock rpm dual plane and 650 holley DP,timing and jetting seem close.
I have a 88 chris craft 245 limited last season with stock engine with only intake and carb mods I got 50 gps with 21 mirage at 41-4200 rpm,46 with a 19 P mirage at 4400 rpm,now I get 50 with 19P at 4800 and not sure on 21 yet,I had a vibration start as soon as I started planing with the mirage,I let out and put the 19 back to finish the weekend,I did not want to break anything yet,long weekend!! I will try to find out what the vibration was this weekend.? I thought I may have gotten a tad more,it for sure planes alot better but I hear people going faster than me with stock motors!! boat empty is supposed to be 3800 pounds.
The only thing I did not totally check is enough fuel at the top end,I need to continue plug monitoring to see if they can get darker,pretty light right now,can a (new ) stock pump flow enough?
I am going to do a compression check to see if everything is cool.
What kind of power numbers can I expect?
For now I reused my short block,280 hrs,very well kept and clean,I have dart sportsmanII heads with 64 cc chambers,cam is crane 114 lca 212/[email protected] with.446/.459 lift with an edelbrock rpm dual plane and 650 holley DP,timing and jetting seem close.
I have a 88 chris craft 245 limited last season with stock engine with only intake and carb mods I got 50 gps with 21 mirage at 41-4200 rpm,46 with a 19 P mirage at 4400 rpm,now I get 50 with 19P at 4800 and not sure on 21 yet,I had a vibration start as soon as I started planing with the mirage,I let out and put the 19 back to finish the weekend,I did not want to break anything yet,long weekend!! I will try to find out what the vibration was this weekend.? I thought I may have gotten a tad more,it for sure planes alot better but I hear people going faster than me with stock motors!! boat empty is supposed to be 3800 pounds.
The only thing I did not totally check is enough fuel at the top end,I need to continue plug monitoring to see if they can get darker,pretty light right now,can a (new ) stock pump flow enough?
I am going to do a compression check to see if everything is cool.
What kind of power numbers can I expect?
#2
Registered
Re: small block question heads/cam combo
Four MPH gain for what you did with a SB in a heavy boat is decent, I built a 383, Dart heads Pro Mod Lunati internals and a reasonable cam. I have a 22 Donzi 3200 pounds and gained four & a half, it takes a lot more HP then most realize to make big speed gains in any boat.
Phil
Phil
#4
Gold Member
Gold Member
Thread Starter
Join Date: Oct 2005
Location: Olmsted Falls,Ohio Marblehead,Oh
Posts: 11,635
Likes: 0
Received 204 Likes
on
132 Posts
Re: small block question heads/cam combo
Originally Posted by MOP
Curious what you have your top timing set at?
If I can remember the timing is at around 30 total,I am going back to do more tuning this weekend,I did not want to mess with it much on a holiuday weekend,I am worried why the boat vibrated with the 21 mirage,I did not even let it plane to see,I put the 19 on and it was smooth,i kn ow the prop is ok because I ran it last year,I may not have had it seat right..??
I will try again on sat for the 21.
#5
Registered
Re: small block question heads/cam combo
I brought up top timing as I went a bit conservitive at first running 30 degrees, bumping up to 32 degrees which gave me just short of 1 more MPH.
Phil
Phil
#7
Gold Member
Gold Member
Thread Starter
Join Date: Oct 2005
Location: Olmsted Falls,Ohio Marblehead,Oh
Posts: 11,635
Likes: 0
Received 204 Likes
on
132 Posts
Re: small block question heads/cam combo
Originally Posted by BajaRunner
the cam seems small.
#8
Gold Member
Gold Member
Thread Starter
Join Date: Oct 2005
Location: Olmsted Falls,Ohio Marblehead,Oh
Posts: 11,635
Likes: 0
Received 204 Likes
on
132 Posts
Re: small block question heads/cam combo
Originally Posted by MOP
I brought up top timing as I went a bit conservitive at first running 30 degrees, bumping up to 32 degrees which gave me just short of 1 more MPH.
Phil
Phil
#9
Re: small block question heads/cam combo
Originally Posted by 245 limited
Mine? I figured I was going to try to keep some torque in it,I did a few different cams on desktop dyno and this seemed the best for my application,I could not get any good answers from anyone on the net or local engine builders so I did as much as I could,I will take any recommendations from people if they have them,this was the first chevy engine I ever built,I have all fords on the street.
maybe the cam experts will chime in.
#10
Gold Member
Gold Member
Thread Starter
Join Date: Oct 2005
Location: Olmsted Falls,Ohio Marblehead,Oh
Posts: 11,635
Likes: 0
Received 204 Likes
on
132 Posts
Re: small block question heads/cam combo
I agree,not knowing alot about chevys I was trying to keep it simple,I can change cams fairly easy if I remove the seat,I may if someone can tell me what to run!!.