PDA

View Full Version : Replacing/ Upgrading Cylinder Heads


O2BESOHUGE
02-09-2012, 11:07 AM
http://www.ebay.com/itm/350526655199?ssPageName=STRK:MEWAX:IT&_trksid=p3984.m1423.l2649

ARE THESE WHAT I NEED? THE 302/351 GT40P HEADS? IVE SEEN WHERE FOLKS HAVE GONE WITH THE GT40 AND SOME HAVE SAID THE GT40P. WHICH ARE BETTER?

WILL MY STOCK MASTERCRAFT VALVE COVERS FIT ON THESE?



THANKS GUYS!
JAY

thatsmrmastercraft
02-09-2012, 11:22 AM
Those are the heads. You will need to get the bolt holes drilled out to 1/2".

O2BESOHUGE
02-09-2012, 11:49 AM
Why Is That? Thanks!

rjracin240
02-09-2012, 12:31 PM
Why Is That? Thanks!

the GT heads are drilled for a 7/16" head bolt, the 351 has a 1/2" head bolt easier to drill the heads than make the holes in the block smaller!

Not that big a deal to get tehm drilled at a machine shop

O2BESOHUGE
02-09-2012, 12:48 PM
Ok...now You Guys Run The Edelbrock Performer Intake With These Heads Right?

Thanks For The Tips!

thatsmrmastercraft
02-09-2012, 01:06 PM
The Performer is a perfect intake for that application.

O2BESOHUGE
02-09-2012, 01:08 PM
How Much Of A Difference In Gas Will It Drink With This Set Up Vs. The Stock Heads And Intake? Runnign The Same Holley 600 Carb?

Big Difference?

thatsmrmastercraft
02-09-2012, 01:08 PM
the GT heads are drilled for a 7/16" head bolt, the 351 has a 1/2" head bolt easier to drill the heads than make the holes in the block smaller!

Not that big a deal to get tehm drilled at a machine shop

If one's insanity took you to never drilling a head, I suppose you could use the 7/16" head bolts and Heli-coil the block:rolleyes::D:D

1redTA
02-09-2012, 02:02 PM
which motor do you have the 240 or 280 hp 351W? when I do the P's for my 240hp I'm stabbing a 280hp cam while I'm in there

thatsmrmastercraft
02-09-2012, 02:17 PM
which motor do you have the 240 or 280 hp 351W? when I do the P's for my 240hp I'm stabbing a 280hp cam while I'm in there

Nice plans. What cam are you planning on using?

O2BESOHUGE
02-09-2012, 02:59 PM
i have the 240 hp engine... i thought adding the new heads and intake would be pushing it up to the 285 hp mark

thatsmrmastercraft
02-09-2012, 05:55 PM
i have the 240 hp engine... i thought adding the new heads and intake would be pushing it up to the 285 hp mark

The heads are good for 30-40hp depending on who you talk to. The intake should be good for 15 more or so. The good thing about these mods is you will feel them in the across the board..........not just on top end.

CantRepeat
02-09-2012, 06:05 PM
Sure wish Kyle would drop a note or two on this post!!

/nudge

O2BESOHUGE
02-09-2012, 06:20 PM
Do You Guys Know The Correct Part Number For This Intake? I See Them That Say Non Egr? I Dont Know Which To Get

Thanks!

thatsmrmastercraft
02-09-2012, 06:23 PM
Do You Guys Know The Correct Part Number For This Intake? I See Them That Say Non Egr? I Dont Know Which To Get

Thanks!

You want #7181 is the satin finish non-EGR.

http://www.edelbrock.com/automotive_new/mc/manifolds/ford/perf_rpm-289.shtml

etduc
02-09-2012, 06:31 PM
Do You Guys Know The Correct Part Number For This Intake? I See Them That Say Non Egr? I Dont Know Which To Get

Thanks!
Get the non-egr. Remember, your bottom end is designed for low to mid rpm. (It's a truck engine.)
I believe peak horse power, 240hp at 4500rpm. Kyle ran his a few times, for long periods, north of that. But I can attest, it was fast in that configuration. I am sure his new build is quick, and durable.

O2BESOHUGE
02-09-2012, 06:32 PM
Thanks Tmm!!

TRBenj
02-10-2012, 09:45 AM
7181 is the Performer RPM. 2181 is the regular Performer.

The 351w bottom end is plenty strong to sustain RPM well north of 5k. 6k is probably a non issue. "Max rpm" is usually specified relative to where the engine makes peak hp, not where it will start to fall apart. The only attributes of the bottom end that influence where peak power occurs are how many ci it provides (bore x stroke) and the dome or dish of the piston (which affects compression ratio). There are a lot more things on the top end of the motor that influence where the peak hp occurs (flow dependant)- heads, intake, cam, exhaust. Generally, the bottom end just has to be strong enough to support the RPM you want to run and doesnt have much of an effect on power.

O2BESOHUGE
02-10-2012, 10:23 AM
So Which Is It? :)

hosofpayne
02-11-2012, 06:17 PM
which motor do you have the 240 or 280 hp 351W? when I do the P's for my 240hp I'm stabbing a 280hp cam while I'm in there

how do you find this out? engine number? boat serial number?

1redTA
02-12-2012, 08:20 PM
how do you find this out? engine number? boat serial number?

I believe the HIN as the answer. can't tell you more on the iPhone :-)

thatsmrmastercraft
02-12-2012, 10:22 PM
Don't take this as gospel, but I believe the 280hp engines all came with a 4150 carb. Of course, if the carb has been changed to a 4160.......

Dino Don
02-12-2012, 11:32 PM
You want #7181 is the satin finish non-EGR.

http://www.edelbrock.com/automotive_new/mc/manifolds/ford/perf_rpm-289.shtml

What's the performance difference between a 7181 and a 2181 intake?

thatsmrmastercraft
02-13-2012, 12:11 AM
What's the performance difference between a 7181 and a 2181 intake?

The 2181 is a Performer intake with a rpm range from idle to 5500 rpm.
The 7181 is a Performer RPM intake with a rpm range from 1500 to 5500 rpm.
http://www.summitracing.com/compare.aspx
The RPM version flows a little better than the base Performer and will respond better to the increased flow capability of the GT-40P heads.
http://www.edelbrock.com/automotive_new/mc/manifolds/manifolds_main.shtml

Dino Don
02-13-2012, 12:13 AM
Is the 7181 a little taller? More down draft?

thatsmrmastercraft
02-13-2012, 12:30 AM
Is the 7181 a little taller? More down draft?

The 7181 carb base height is .775" taller than the 2181. Not sure if that is enough height difference to straighten out the runners, or if construction is different.

hosofpayne
02-13-2012, 10:38 PM
Don't take this as gospel, but I believe the 280hp engines all came with a 4150 carb. Of course, if the carb has been changed to a 4160.......

My boat is all original. To the best of my knowledge only two people have worked on it so 99% chance carb. is factory. How do i tell the difference between 4150 and 4160. I have been working on cars, trucks and boats my whole life but unfortunately i have little holley experience. Thanks and what is the HIN? PS sorry didnt mean to JACK thead

thatsmrmastercraft
02-13-2012, 10:53 PM
My boat is all original. To the best of my knowledge only two people have worked on it so 99% chance carb. is factory. How do i tell the difference between 4150 and 4160. I have been working on cars, trucks and boats my whole life but unfortunately i have little holley experience. Thanks and what is the HIN? PS sorry didnt mean to JACK thead

The 4150 has a dual inlet carb and the 4160 has a single inlet carb. The inlet refers to the hard fuel line going from the fuel pump to the carb.

The 4150 is the top picture.

O2BESOHUGE
02-14-2012, 11:38 AM
4150 Drinks Way More Gas!!

thatsmrmastercraft
02-14-2012, 12:10 PM
4150 Drinks Way More Gas!!

4150's are calibrated to flow more fuel as they were on the 280hp engine. It also seems that as these carbs get older, they like to provide more fuel than the engine can handle, especially at idle.

TRBenj
02-14-2012, 02:41 PM
The 4150 has a dual inlet carb and the 4160 has a single inlet carb. The inlet refers to the hard fuel line going from the fuel pump to the carb.

The 4150 is the top picture.
You are confusing the 4010/4011 with a 4150. Your picture shows the former. The top mount fuel bowl screws are one obvious hint.

The 4150 is very similar in design to the 4160. The type of fuel line used (single vs. dual feed) is not a determinant between the 2 types. The larger 4160's (750cfm and above) use dual feeds, just like the 4150's. The only "hard and fast" rule I know of to differentiate the 2 types is the fact that 4150's have metering blocks with replaceable jets on the secondaries, where the 4160's have a fixed plate (which can be converted, if you so choose).

thatsmrmastercraft
02-14-2012, 04:16 PM
You are confusing the 4010/4011 with a 4150. Your picture shows the former. The top mount fuel bowl screws are one obvious hint.

The 4150 is very similar in design to the 4160. The type of fuel line used (single vs. dual feed) is not a determinant between the 2 types. The larger 4160's (750cfm and above) use dual feeds, just like the 4150's. The only "hard and fast" rule I know of to differentiate the 2 types is the fact that 4150's have metering blocks with replaceable jets on the secondaries, where the 4160's have a fixed plate (which can be converted, if you so choose).

Thanks for fixing my mental lapse. Start off on a tangent and you need someone to redirect:confused::rolleyes:

learjet2230
03-01-2012, 07:00 PM
4150...... Mechanical Secondaries
4160...... Vacuum Secondaries

TRBenj
03-02-2012, 10:54 AM
4150...... Mechanical Secondaries
4160...... Vacuum Secondaries
That is consistent with the marine carburetors currently listed on Holley's website, but I know that I have seen marine 4150's with vacuum secondaries before.

Here is an automotive 4150 with vacuum secondaries:

Holley 850cfm 4150 at Summit (http://www.summitracing.com/parts/HLY-0-80531/)

So, like I said, the only hard and fast rule I know of to differentiate between a 4150 and 4160 is the rear metering block (4150) vs. fixed plate (4160).

learjet2230
03-02-2012, 03:32 PM
yes sir you are correct! To take your statement one further...4150's have removable secondary jets (in the metering block), while the 4160 has a fixed metering plate. But as far as marine carbs you will be hard pressed to find a mech secondary 4160. I was just keeping it simple because most dont know what a metering block is!!

TRBenj
03-05-2012, 12:28 PM
yes sir you are correct! To take your statement one further...4150's have removable secondary jets (in the metering block), while the 4160 has a fixed metering plate. But as far as marine carbs you will be hard pressed to find a mech secondary 4160. I was just keeping it simple because most dont know what a metering block is!!
Correct- the replaceable jets are the advantage of the block vs. the fixed plate.

I dont *think* a mechanical secondaries version of the 4160 exists, but am almost positive I have seen a vacuum secondaries marine version of the 4150, just like the automotive version I posted above.