New guy, Newish Boat

For Trey .. do you need a new cam?   Somewhere posted around these parts is a spec for the original gt40 cam, I am sure there is one on summit available for relatively cheap, I wouldn't change much there for the reasons stated previously.

Gary, for your shamrock I would get a 50,000 mile roller 351 out of a junkyard and run the whole longblock. Not the easiest thing to find but not the hardest either- 96 broncos or f250s on www.car-parts.com used to get it done for me. If I told them I was using them for the block and didn't want a warranty it used to be about 600 delivered for an engine but it depends greatly on the area. I have been buying fully machined and ready to go stroker prepped roller blocks for around 1k shipped - not cheap but good machine work and you don't have to root around the junk yard - but like tim said you would still need all the rockers and whatnot, a whole junkyard pull out comes with all that and you can just add the cam of your choice.

TRBenj wrote: First off, I'd be very careful about changing too much on the induction side (heads, cam) on a gt40 as the ECM is not capable of making tune variation based on different (better performing) components. P heads are a proven deg upgrade over gt40 heads but i probably wouldn't push it much beyond that in terms of flow or cr improvements. Eddie, is your 383 roller? I can't remember.

Good point Tim. Didn't even consider the whole ECM thing on an EFI engine.

Yes, I went with a complete roller valve train. Retrofit roller lifters and roller rockers. Is it worth the cost (about $1200 total on a non-roller block). Yes and no.
I don't have to be concerned about the oil I'm using having enough ZDDP but if that oil provides better lubricating properties over non-ZDDP oil, I find myself still using it so that's not really a benefit at this point.

When I first started the engine, there was fuel delivery issues i.e. dirt from the fuel pump that messed up my needle/seat flooding the engine. Then again, after installing a new fuel pump that was putting out too much pressure holding open the needle/seat, flooding the engine. These issues only allowed the engine to run a few minutes each time I got it started before it flooded itself out which didn't hurt the roller cam at all but would've probably wiped a flat tappet cam.

As for the performance, I'm sure it has to be better performance than the non-roller setup but I really can't say what that difference really netted.

You also have to consider the other "gotcha's" when upgrading to a roller setup that might be overlooked. Stock valve covers are no longer usable. The roller rockers required new locking stem nuts which required taller valve covers. Granted, that's if you decide to go with roller rockers. I personally feel that a roller cam/lifters deserve roller rockers to complete the whole valve train package but that's just me.
Then different length pushrods, valve springs, spring keepers, possibly spring shims, etc. etc. etc.
In the case of my SBC, a new cam cover was needed for the roller cam thrust bearing. I have no idea if the SBF would require the same thing but I assume it would.
Again, all these things are not horribly expensive but the overall cost is effected and needs to be considered.

A block that is setup for a roller cam would be much less expensive than a non-roller retrofit type setup that I had, but I humbly feel your $400-$500 upgrade cost is still terribly underpriced if you consider all the potential "gotcha's". Not putting in roller rockers will definitely be a much cheaper overall cost.

Is the performance increase worth the cost in a non-roller cam...probably not when figuring what gives you the most bang for your buck...the stroker kit or the retrofit roller cam setup (which were both very close to the same cost each for me)????? Then again, was the overall engine package worth the investment?
With almost 200 hrs. since the rebuild I can honestly say ABSO-FREAKIN-LUTELY.

Still nothing like yours or Joe's rockets but it still puts a smile on my face every time I fire it up and even more when I holler "Hit It".
No regrets at all   

Orlando76 wrote: I know more about the female brain than I do computers

Try F12.

Gary, if you can find a roller block for little $ over a flat tappet, sure. The tie bar lifters are a real nice solution (and work great on a flat tappet block) and are "only" ~$400 for a SBF. Joe and I are both running tie bar lifters on our rollers.

Yep, plenty of options to set up a custom tune- mega squirt being one of them. Like you said, the tricky part is getting the base tune to start from, PCM has it locked down.

Look up Megasquirt Steve. If I remember right lewey is building one

I found a stock '95 block with roller cam and lifters for my stroker project.
They're out there but hard to come by. I went all new cam, lifters, rods etc. of course. I just wanted the roller set up block, spider tray and and lifter forks.

Gary S wrote: Joe, your thoughts this. Say you needed another block for a lefty, would it be worth while to source s late model 351 out of a truck so to take advantage of the roller block?

Gary,
You still have to acquire the roller lifters, the spider tray and probably new push rods as well as the roller cam. Then if you really wanted to go all out you can upgrade to roller rockers as well.
Still an awful expensive upgrade. IMHO you're still going to get more bang for your buck adding P heads, an intake and a cam than you ever will with roller lifters. At least in our somewhat mild marine applications or until someone like Joe or Tim gets to making more serious HP. That's when a roller valve train can start making a difference.

All SBC motors made after 87 were milled with deeper lifter bores and drilled/tapped for the spider tray to accept roller lifters. Even if the engine didn't come equipped with roller hardware. How many guys you think took advantage of that and upgraded? I'm guessing very few.
Sourcing a block made for roller hardware "just in case I decide to upgrade" I wouldn't consider a factor unless you're going to upgrade. You either make the jump or you don't. At least in my feeble minded personal opinion.

Gary S wrote:

Curious myself since you linked that ad to my wanted post.

My understanding and please correct me if I'm wrong but, my block is/was machined to accept a roller cam but they didn't go to an actual roller motor (ford trucks anyway) until 1996 and my motor is basically a 93-95 truck block with gt40 Upper/Lower Intake and Heads.

I think I've read so much on the subject in the last few weeks I'm way more confused than when I started

JoeinNY wrote: [/QUOTE

Machine shop I am using has another set of GT40s that are ready to go with new springs and what not. He and I looked at them before as an option if mine were bad. I would be fine with the "P"s if I need to go that route for some reason. I will for sure end up with one version or the other of the GT Heads... Not going back with an E7 or whatever came as the "base" head.

Hopefully the block comes back good to save me a little coin.

Heads are both cracked. They haven't cleaned and broken down the block yet.

Looks like long block ahoy.

I think I cleaned up the quoted picture...

I'm glad the boy is into it as well. His mom is coming around too now that it looks a little nicer.

I am not sure it is cost effective to have your heads rebuilt anyway... you might check the cost of a set from Clearwater or one of the other Cyl head folks.   lots of folks here have talked about GT40P heads, I am not sure if the fit works with a later model GT40 boat, but would be worth checking.   My guess is that the setup time for someone who does these heads all the time is going to bring the cost down over your local machine shop.

good luck!

also - as a forum etiquette thing, especially with pictures, you don't need to quote the last post, as it takes up server space. it's helpful when you have multiple posts between what you are responding to and your response, but otherwise it's not necessary, just call out the screen name/name of the person your responding to and we'll generally follow the trail

Just a heads up, Your machine shop is probably well aware of this but overheated small block Ford heads are known to crack between the valves. Might be hard to see in this photo but it's there.

That dropped valve seat screams overheat so make sure you check the cooling system before running the new motor. Also how do the spark plugs look, are the electrodes disintigrated or intact? Another cause of extreme damaging heat is low fuel pressure and the FCC being missing points to a problem there. High rpms (full throttle) and low fuel pressure can melt a GT40 pretty quickly.

Sounds like you probably won't reuse the heads but just for forensic measures put a straight edge across the valve stems(rocker end) and see if they are all the same height. Extreme heat will get those valves so hot they will Tulip into the head, you'll think the valves are all different lengths.