3800 M90 Build

Ok the cats out the bag!!im going supercharged .its a 3800 gm m90.i need lots of help as im a nos guy.for starters my list of mods is in my signature.the guy im buying it from ran it on a stock tuned motor at 3psi.first question is what is the "safe" limit to run boost at?i know it is not ideal but i have a wide band O2 and will be doing tuning very soon.i also will be trying to have my company make a new lower intake mounting bracket on the cnc machine and have it taped for nos/water meth injectors/spray bars.i will also be getting a p+p unit from 3800 performance and stepping down on the pulley to try and run 8-10psi.what size injectors should i run for that?which fuel pump should i run?any suggestions on tuning?i was going to go mega squirt but i see sct has a new chip out,any suggestions?


DONE
ported and polished gm 3800 gen 2 m90
Water to air intercooled
port matched 76mm inlet and intake tube
mustang 75mm race tb
90mm maf
36lb injectors
255 fuel pump
sct 5bank dyno tuned
2.7" pulley 10lbs of boost!!

dyno run,these was the last two pulls with the 2.7 and the alternator was bad.turn your volume down!!


and a 3.25 pull and think my rev is still set to 5000 in this one

 

[mr cribb]

I have to ask is it worth every dollar spent?

Cause it sure looks bad@$$!

 

[jd4242]

I have to ask is it worth every dollar spent?

Cause it sure looks bad@$$!

To the average person...absolutely not worth it.i just wanted something different and the badest v6 around.you should see peoples face when i tell them its a v6plus it puts a smile on my face every time i start it up and smell that smell of raw power.its sooooo fun to drive also.

and who can put a price on happiness ,that's priceless!!to me its well worth every grand that went into it

 

[mr cribb]

Truthfully as long as you're happy with the outcome, then it doesn't matter what anyone else thinks.

I was just curious if it was worth it all, money and frustration. I know you have thousands invested in cash, and several thousand hours in time.

If I had the money and resources and (the wife's approval ) I'd go all out in mine. She has denied my request for a 302 swap at the present time, .

 

[jd4242]

Just an update.i blew the head gaskets off the motor last weekend.guess 10lbs of boost and 10.67:1 compression is to much for the ohv with stock head bolts.also im not 100% sure i used blue HD headgaskets last build.i know i did the first time,second time i used ebay crap and the last build for some reason i think they was red gaskets.i would figure i would order the same ones as i did the first time but for some reason i wanna say they were red.ill be swapping heads to a set that's fully ported and polished with way larger valves.ill be using blue HD gaskets and head studs this time.ill post some pics and info once i start tearing it downwe now know the limit of the ohv upper end!!

 

[Bruces expo]

Sorry to hear about The Gaskets , Glad to hear about the Ported Heads With Bigger Valves !

 

[Dono]

Well boys, here we go again!
At least it isnt too late for me to learn from JD's rather painful experience and take steps against this happening to me in my build.

Stupid stretch (tty) head bolts. Another bad idea when you start making a motor do stuff it was never designed to do.

so, over 10.5 compression and 10lbs boost is bad. I was at about 9.5:1 compressions with 10 lbs boost. I wonder what JD's heads will be like. Id be interested to find out if they are warped and cracked also.

I think were pretty safe to say that JD will have the strongest 4.0 ohv of anyone on this board, ever!

 

[jd4242]

Well boys, here we go again!
At least it isnt too late for me to learn from JD's rather painful experience and take steps against this happening to me in my build.

Stupid stretch (tty) head bolts. Another bad idea when you start making a motor do stuff it was never designed to do.

so, over 10.5 compression and 10lbs boost is bad. I was at about 9.5:1 compressions with 10 lbs boost. I wonder what JD's heads will be like. Id be interested to find out if they are warped and cracked also.

I think were pretty safe to say that JD will have the strongest 4.0 ohv of anyone on this board, ever!

Really hoping the 95tm heads are still good.im going to have them checked and they will be up for sale.still trying to save up for the new heads,they are the highest cfm heads anyone has seenthey also will take me back down to 10:1.i think im the only one that pushed the OHV to the limits i have.its going to be awile though,it costed me over $600 to get it towed back homeyour motor is in the same boat,just glade you had time to get some head studs

 

[wood1]

that sucks buddy, I guess it's like they say... drive it until you break it then make that part stronger, repeat.

 

[jd4242]

well just pulled the plugs and all looked really bad.all show signs of water and was wet but smelt like straight gas.one plug looks really bad but ive been having problems with that one when my delta rockers blew up.pretty sure it needs a new valve guide or seal but i have never seen the chunks on it,just normally really oily.compression test didnt tell me anything,in order of firing,200,190,195,200,210,215.i think some of the cylinders where a little wetter than others but those arent bad numbers.i definitely got some water in my oil,not a whole lot tho,very little.its not showing on my dipstick,just in the cap and my crankcase filter.also you can see bubbles in my radiator and white smoke when warm.im thinking more towards a cracked head

plugs for thoughts,these are brand new,put in before trip(same order as compression test)

 

[jd4242]

Man no comments or questions?guess next step is to pull it apart and see what i seegoing to be awile tho

 

[Dono]

It is strange that compression is still really good. That one blug looks like it wasnt firing anymore at all.

I do want to see what the head gasket looks like. Your not going to pull the motor to get the heads off are yo?

 

[jd4242]

It is strange that compression is still really good. That one blug looks like it wasnt firing anymore at all.

I do want to see what the head gasket looks like. Your not going to pull the motor to get the heads off are yo?

It was firing.tested it.that's the plug that gets oil on it all the time,the chunks have never been there.that's where the delta rocker blew up and caused the valve to stick open.pretty sure it needs a new guide and seal.i really want to pull the motor but my lift is the only lift that reaches high enough to pull it and its huge,also my dad loaned it to his boss.i may be pulling the heads with the motor in the truck.the compresstion is throwing me off.why i think its a cracked head.gets larger with heat and boost.those two are low tho,think i was around 210-220 new.going to do a leak down once i get the charger,valve covers and rocker arms off.

 

[rickybobby]

definatly do the leakdown test, may only have to pull one head for now, or may find its an intake issue

 

[jd4242]

The very first plug is what they looked like when i changed them last.but i was running very rich.think it was a sign of a leak making it rich.just started doing that the last two weeks.i have reached 230-240 three times before the charger went in,think i may have added to this problem.

 

[rickybobby]

not really seeing any signs of burning coolant on the plugs, those look like burning just a tad rich. burning coolant usually turns the plugs white and leaves deposits, and if its really bad you will find the plugs really clean, looking almost new

 

[jd4242]

definatly do the leakdown test, may only have to pull one head for now, or may find its an intake issue

When i had issues with lower intake i was getting way more water in the oil.i battled that for the first three build.either way im getting new heads and head studs.

 

[jd4242]

not really seeing any signs of burning coolant on the plugs, those look like burning just a tad rich. burning coolant usually turns the plugs white and leaves deposits, and if its really bad you will find the plugs really clean, looking almost new

It was burning SUPER RICH!i have full gauges and they smelt like gas.but what is on the plugs is rust.they were wet when i pulled them out and after they dried it turned to rust.also the last set was like a month old and it was burning super rich and looked nothing like they do now.all looked like first plug.before that the set i had put about a 1000 miles on when it was running right(minus the one plug)still looked brand new,picture perfect

 

[jd4242]

O just a fyi my coolant is straight rust water.i didnt run coolant for a year and have been filled full of rust.I've have flushed it about 15 times and ran a cleaner through it to get it to where its half way clean.did all this and replaced the rad right before my trip.before it blew.

 

[boominXplorer]

You could have a crack in the head in the intake runner pulling water in only when running hence the good compression numbers.

 

[jd4242]

You could have a crack in the head in the intake runner pulling water in only when running hence the good compression numbers.

Yea what im thinkingto me all signs say cracked head.but seeing bubbles in the rad and slight water in oil