2.4 upgrades....shavin heads?

[steady streamin]

Well I have had the boat for two years now, and think its time to dig into the upgrade department. I have been doing some reading on some common upgrades for '86 2.4l 225. I see most people recommend shaving or cutting the heads to get the higher compression. Right now I am just showing 122 on all six. Is it as easy as pulling them off and getting it done, and putting them back on? Does anybody recommend someone to do the work, and how much does that normally run? And help, or any other ideas would help.

The guy i got the boat from said the carbs had been reworked, boyensson reeds, solid motor mounts... so trying a little more.

[olmo40]

First off id do a leakdown test to determine condition of motor ,Heads alone IMO wont do a whole lot yuo can safely go to 145psion pump gas ,some will say more ,try searching here or contacting a supporting vendor .There are some good "Stage 1" bolt on mods you can do depending on your budget .Best place to start is with prop and engine height :thumbsup:

[HStream1]

Well I have had the boat for two years now, and think its time to dig into the upgrade department. I have been doing some reading on some common upgrades for '86 2.4l 225. I see most people recommend shaving or cutting the heads to get the higher compression. Right now I am just showing 122 on all six. Is it as easy as pulling them off and getting it done, and putting them back on? Does anybody recommend someone to do the work, and how much does that normally run? And help, or any other ideas would help.

The guy i got the boat from said the carbs had been reworked, boyensson reeds, solid motor mounts... so trying a little more.

Heads are definately a HP gain bang for the buck.

122 is a good read for compression on that motor. As suggested do a leakdown. You can have good cranking compression and a questionable leakdown. IMO stay under 8% leakdown on a motor such as yours.

If you show a good leakdown you can go to 32cc's on a 2.4 and hit the pump gas target of 140/145 psi. IMO if I were you I'd get a nice set of TDR reeds to go with those milled heads.

When my Mill is down (which it is right now) I always send my heads to Jay Smith. Jay does a fantastic job, with a quick turn around and a little something special that no one else does. Contact him first so he knows to be expecting them.

Total cost for the heads and reeds + S&H should come to around
$350.00 ish.

Also as mentioned Prop and engine height play a very important part of the equation in acheiving performance. Although you will be limited on engine height unless you have a LWPU lower.

Good luck!!

[T-REX]

IMO, a 1" spacer and cut tha front .050" iz tha biggest bang for tha buck...After heds are cut...

[HavasuDreamin']

Is it as easy as pulling them off and getting it done, and putting them back on?

No. You need to have the carbs rejetted. Also, whoever cuts them needs to know what they are doing. You don't want warped heads.

If you motor is stock, I would spend the money on the gear case enabling you to jack the motor up on the boat. If your gearcase is done, as HStream1 said, heads, reeds, and exhaust (all together) should net you some results.

HD

[terry taylor]

No. You need to have the carbs rejetted. Also, whoever cuts them needs to know what they are doing. You don't want warped heads.

If you motor is stock, I would spend the money on the gear case enabling you to jack the motor up on the boat. If your gearcase is done, as HStream1 said, heads, reeds, and exhaust (all together) should net you some results.

HD HI. rejetted , could you explain this ,witch jets and for what reason.Also what will happen if you or anyone does not rejet . In other words please explain the principal thanks.

[steady streamin]

I am going to run a leakdown test first to see. The thing is i am just learning about this stuff so when i got the boat the guy said alot of things that he had added to the motor. And almost the day i bought the boat the guy's number was disconnected (delaminated just after i got it, and he guaranteed that the core was solid). But he mentioned that he put the boyeson 7 petal reeds, had the carbs redone and that he had to send them off to get tuned right, i believe it has a carb spacer, and he tinkered with the exhaust because it is loud as %&$t. It has a low water pick up, and can run upto two inchs above the pad if i wanted to, but i only run about 3/4 of a inch with a 5-1/2" set back. I am looking for a mazco 29 also to add to the mix. I have a 30 et(seems just a bit much), and ran a 28 big ear last year(pulls hard, but revs high).

[olmo40]

What numbers you running now with both props ,Can you confirm speed is GPS.If you also let us know what size Main jets are in it, somone smarter than me will tell you if you may need to go bigger ,A lot of times when motors are played with they are jetted way too fat .

[mercat]

IMO, a 1" spacer and cut tha front .050" iz tha biggest bang for tha buck...After heds are cut...

I understand the 1" spacer, why the .050 cut.?.

[WATERWINGS]

I have heard that, but don't get it either......why move an inch further away, and then .050 back closer?

I'm sure there is a reason behind it......can someone explain?

[mercat]

I do have mixed feelings adout the spacer.. Sure that rod swinging by there creates some turbulance, but it still has to pass thru.. I cant see adding all the volume to the crank case..

[Merc ModVP]

I'm no expert but .050" off puts the reeds further in the block creating more crankcase pressure.

[mercat]

Where is the spacer? Carbs and reeds, reeds and crank case?

[WATERWINGS]

I have the spacer, and it is an addition that you can actually feel.

I don't think it changes top end any, but the midrange acceleration is noticable.


I understand what you mean about crankcase volume, but my 2.4 responded nicely to the spacer, and gained, not lost performance.

[DerStream]

The 1in spacer is between the Intake & Front half, the reed cages are mounted to the back of the spacer so the reed cages are in the same place whether there is a spacer or not. The Spacer straightens the air coming into the motor. Helps on bottom & midrange, not really for top end performance, doesnt hurt it though.

Shaving the front half .50 brings the cages further into the motor & decreases crank case volume & increases crank case pressure.

[HStream1]

The 1in spacer is between the Intake & Front half, the reed cages are mounted to the back of the spacer so the reed cages are in the same place whether there is a spacer or not. The Spacer straightens the air coming into the motor. Helps on bottom & midrange, not really for top end performance, doesnt hurt it though.

Shaving the front half .50 brings the cages further into the motor & decreases crank case volume & increases crank case pressure.

Dam :thumbsup::thumbsup: Well put and right on.

[Jay Smith]

DerStream ....I couldn't have said it better !!!! Any reduction of space BEHIND the reed increases crank case compression that = increased torque, and air speed.....

Jay

[WATERWINGS]

That makes sense.....how much is to much to take off, and will you actually start hurting performance?

I assume at some point, the crank will start to hit the reed cages?

[Jay Smith]

Rod bolts will hit if you cut too much... You can cut sooo much off the front flange will become weak and brittle...I normally cut .050" off and do a bunch of added machine and putty work to the front half..

Jay

[steady streamin]

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guess it doesnt have carb spacer, but did notice the carbs are wh-20-1. Is that a good carb?

[gmacrae]

So if you're talking about an injected 2.4 (like my laser 220), and i have the heads and front shaved, does anything need to be done to keep it fueling safely? Could those mods cause it to run lean or is the stock tune fat enough to not worry? A spacer sounds like a good way to increase intake velocity but I'd have to move the ecu

[T-REX]

but did notice the carbs are wh-20-1. Is that a good carb?


Tha best U kan have, IMO!!....Easy to tune, and have solid reputations!!:thumbsup:

[mercat]

The spacer makes sence now, that intake leaves alot to be desired directing the air with those steep angles.. It looks to me the engine is a 7pedal 2.4 ,225hp, 1980, 81... That is the front half i put on my bridgeport.. Its the only two years produced..

[ScarabEpic22]

Back from the dead I know, but I have a few questions about cutting the heads and front half of the motor on an 87 Laser 2.4L. I want to run 91 octane (all we get here in WA/ID) and I need to have my motor rebuilt so Id like to have this all done at once. Is 0.050" a good amount off the front without doing anything else except shaving (ie no adding support, strengthening, etc)? Ive read T-REX and Jay recommend ~0.050" off the heads as well as deck the block 0.050" (not exactly sure what this is so Id like to know more before I continue) a few times.

Any other recommendations for the heads? Ill talk to whatever builder I end up going with about these mods as well, I cant do them myself and I just want a reliable motor that works EVERY time, something that hasnt been true for 10+ years now. Also I will be going with a Brucato ACU, ditching that POS factory ECU thats utter garbage.