550 H.P. HydroLock

[custom mccannix]

just out to say that this past weekend I had just finished building my brand new Pontiac 400 6.6L engine. We where at the dyno and almost finished doing the run, running it up for the last reading she talked to us at 550Hp and 575 ft. lbs. of torque, when she blew the head gasket and hydrolocked the number 7 cylinder. At 4000 rpm she came to a dead stop for a split second then sheared the block, crank, cam and all right between numbers 7 & 5 cylinders. laid to rest I will start on number two!


CAn anybody help to understand why the head gasket blew, especially after great care and effort was put forth. I have never had this problem on a small block chevy and not to familiar with the pontiac 400 but I know that it should not have done that.

[volkerc]

Originally Posted by custom mccannix

just out to say that this past weekend I had just finished building my brand new Pontiac 400 6.6L engine. We where at the dyno and almost finished doing the run, running it up for the last reading she talked to us at 550Hp and 575 ft. lbs. of torque, when she blew the head gasket and hydrolocked the number 7 cylinder. At 4000 rpm she came to a dead stop for a split second then sheared the block, crank, cam and all right between numbers 7 & 5 cylinders. laid to rest I will start on number two!


CAn anybody help to understand why the head gasket blew, especially after great care and effort was put forth. I have never had this problem on a small block chevy and not to familiar with the pontiac 400 but I know that it should not have done that.

first off, did you exceed 5500 rpm? if yes there is your first problem, pontiac engines are not rev machines, unlike the chevys, a chevy can run a higher rpm than the pontiac unless the pontiac has been modified to sustain that level of rpm, next what type of gaskets did you use? and when you are going up to those levels of power o-ringing the block/heads might be a good idea also, and last but not least hopefully you torqued the headbolts in 3 steps...?

[custom mccannix]

the engine had a billet crank and mr. gasket copper head gaskets I know about o-ringing the block but that is mainly for boosted engines. the rods were eagle h-beam rods with hyperuetectic pistons from summit. I was sure that it would go at least up to 6500-7000 rpm with ease. and yes we took it up to 6500 several times but didn't reach it before it blew. I actually went in five increments when i torqued the heads, as a practice i have done for years.

[volkerc]

Originally Posted by custom mccannix

the engine had a KRE billet crank and mr. gasket copper head gaskets I know about o-ringing the block but that is mainly for boosted engines. the rods were eagle h-beam rods with hyperuetectic pistons from summit. I was sure that it would go at least up to 6500-7000 rpm with ease. and yes we took it up to 6500 several times but didn't reach it before it blew. I actually went in five increments when i torqued the heads, as a practice i have done for years.

i'd say the 6500 rpm's had something to do with it,, makes me wonder if you didn't spin a bearing before everything else happened, you can read in numerous engine building books and such that 6500 rpm is not good for a pontiac engine, does your block have 2 bolt or 4 bolt mains? also valve float starts at around 5500 rpm depending on the lift,and to reach that power level i'm sure you had a nice aggressive cam in there also...

[TransAm403power]

Originally Posted by custom mccannix

just out to say that this past weekend I had just finished building my brand new Pontiac 400 6.6L engine. We where at the dyno and almost finished doing the run, running it up for the last reading she talked to us at 550Hp and 575 ft. lbs. of torque, when she blew the head gasket and hydrolocked the number 7 cylinder. At 4000 rpm she came to a dead stop for a split second then sheared the block, crank, cam and all right between numbers 7 & 5 cylinders. laid to rest I will start on number two!


CAn anybody help to understand why the head gasket blew, especially after great care and effort was put forth. I have never had this problem on a small block chevy and not to familiar with the pontiac 400 but I know that it should not have done that.

How much did this engine cost to build and produce that much horsepower? I would love to throw something like that into my 79 Bird. If you could let me know the year of the block and a few of the key engine components you used, it could be of great help to me.

[volkerc]

Originally Posted by TransAm403power

How much did this engine cost to build and produce that much horsepower? I would love to throw something like that into my 79 Bird. If you could let me know the year of the block and a few of the key engine components you used, it could be of great help to me.

Hello,
you could check Car Craft, High Performance Pontiac issues, within the last year they had some buildups of those type of engines, I'm in the stages of building my 400, don't mind sharing the components and prices I expect to be in the same power range(if not,I don't care but I'm sure it will make enough power for my car..), here is the breakdown:

1978 400 block $30
1970 #13 heads $200
prepping them another $100
Manley Stainless valves, black melonite $175

Rest of the valvetrain (camshaft,pushrods,springs,retainers,lifters):$110 0
specs of the cam: hydraulic roller competition cams, cam with hydraulic rollers, duration 288/294 lift 520/540.

Harland sharp aluminum roller rockers $200
7 " aluminum BME connecting rods (price new $1500) bought used for $350
set of 8 pistons BME out of DEI Nascar engine (price new $1200), bought used for $100
High volume oil pump $40
Bearings $110
Head gaskets $100
Oil Rings $180
Warrior intake bought used for $300, polishing another $100
Pete Jackson gear drive (new for $250) bought used for $80
Timing chain cover new paid 100 and change, plus $100 to polish
Holley double pumper carb slightly used $120
Crane ignition (not sure but believe I paid $200)
On that you have to add the gaskets, oilpan and distributor
Stock crank 10/10 under $154.

Maybe this info helped you.

[custom mccannix]

to start out I bought a
Crower Billet Steel crankshaft: $2500
Eagle H-Beam Raods With standard Measurments: $569.00
KRE billet four bolt splayed main caps: $265.00
JE SRP pistons:$505.00
KRE lifter bore brace:$190.00
Crane Cams Energizer Cam With 242/242* and .484"lift cam: $140.00
That should get you started on a good strong engine.

Oh yeah it has been checked out by several people and they have told me that the billet main caps had a small air bubble in one and forced it to go, so they are sending me a new set free of charge. I have also been told that the engine was quite solid and capable of well above 9000 rpm if it was not for the air bubble. they vavles will not start floating at 5500 rpm unless it is a stock motor racing engines won't start until 8500 - 9000 rpm's and then the cams are designed to make them float to get the maximum lift. this was just a freak incident and in a few months it will be ready again. I guess I will just have to sit track side this week end and watch. This time alot more will change including the engine will now be a 638 c.i. aluminum pontiac and mean to boot

[custom mccannix]

By the way what every you do do not use a stock crank. You will rip it apart before it would ever get started. Yes they are cheaper but it is worth the money for a billet crank

[76ta]

a 638 ci? crazy.. how much horse you expecting to push...?

P.s if you a a video or sound clip of it i wouldnt mind hearin it

[custom mccannix]

no at this time i do not have any audio or video but i am still working on that. I was told that some geologists that were also avid drag racing fans put one of these engines 50 feet away from a sizemometer and it registered 3.27 at idle and 6.78 at launch on the richter scale. That that's cool!

[76ta]

haha that sounds awsome.. if you get an audio or vid lemme know

[custom mccannix]

will do

[76ta]

thanks

[Blackcrow64]

Old thread... Poll closed, thread locked...