Finally rebuilding motor

[Speedin' Ian]

O.k. so we finally scraped together the money to rebuild the motor, and we are planning on pulling it this weekend, but since this will be our first high perf. rebuild I have a lot of questions.
The motor is a blown 468 running on gas and currently it has a LS7 crank and rods, TRW pistons, roller cam (.610 lift), 990 heads and it is fed via a 671 and two 850's. What we would like to do is use a new chevy block (4 bolt main with billet caps) which we already have, re-use our crank, rods and heads (assuming they check out alright) and then purchase new pistons and a new cam. Also, for now we will be using the same blower and carbs, but soon we will switch to a hat, followed by a larger blower and better ignition a little later. So my first question is where should I buy my parts, such as the cam, pistons, bearings, rings, gaskets, etc... Secondly I think we would feel better if we let a professional assemble the short block, do you guys have any suggestions as to a good shop in the Ventura Couty? Also should we have everything magnifluxed and all our machining done by the same people who put the motor together?
Now for specific parts, obviously we would like to purchase the best parts available, but I am not sure our budget will allow that. Do you guys have suggestions as for what parts we should buy (i.e. pistons, cam, rings, gaskets, etc...) Lastly what type of cam do you suggest? Keep in mind we are running a blown gas 468 making about 14lbs of boost and our heads are limited to about .700 lift due to our valves/spring combo.
I know this post is long winded but we are doing this for the first time on a limited budget and we want to make sure it is done correctly.
Thanks
p.s. oh yeah my buddy has an engine puller but if he flakes does anyone have one I may be able to borrow in the Conejo Valley?

[Fiat48]

What block will you be using? Bowtie or? Siameze?
What cubic inch will it be?
Lake only or race visits?

[blowngas]

I wish you would consider a little better rod than what you have----lunati pro mod rods, howards, crower, manley and others make a strong light rod good for 800 or so horsepower-----always think about what your weakest link might be----sooner or later, you will want to try putting a little more air and fuel in it, so start out with good stuff the first time-----you don't have to pay the highest price for parts to have good stuff----use a good forged piston and stay away from the hyperutetics on a blown setup----if you have the time, shop for a set of pistons and maybe rods also off of ebay----I've bought some good stuff at decent prices----I've even bought new sets off ebay----make sure that it's right for whatever combo you choose----- some guys prefer a .250 longer rod when buying new ones----make sure that the pistons you buy are correct for whatever rod length you decide to go with----have the rods checked over by a shop before using, even if new for correct clearance, ect.----again, like Fiat said, size?, siamese?, race??-----have the new block double checked to insure the crank bore is straight and the clearances are where you want them-----and nothing makes for a good running engine like having a balanced rotating assembly-----especially with new rods and pistons-----are you sure the ol 468 won't stay together for a little while longer in order to save up a few more bucks and put together a good bottom assembly that should stay together the first time?

[Speedin' Ian]

The motor will be in a lake boat and the only racing it will see is at the river. I'm not sure what type of block it is, I think it is the same block as used with the LS7.
The motor is due, it sounds real flat, and it won't RPM. I will consider new rods.

[Hustler]

What about using GT here on the boards? I think he is in your area and can probably get you some pretty good pricing on the parts and do the short block for you. I think his web site is www.tpboats.com or you could call Howard I'm sure thay have his number.

[SSTahoe]

call This guy he can get you some good motor parts for the right price.
Robert 1-800-233-0199..........if you do call him make sure you tell him that Chris in Nevada sent you. He is great and will take care of you.

[Fiat48]

Why changing blocks? Same block as you have now? Old block damaged? Or just because you have it.
Trust me..I am going somewhere with this.

[Speedin' Ian]

The reason we are changing blocks is because our current block has two o-rings and it is a nightmare to seal. Also there is a little pitting in one of the cylinders from what looks like a small piece of metal that took a trip through the combustion chamber, it's really no big deal as it still has good numbers when we performed a leak down but we figured we have the other block may as well use it. Plus the other block has all the machining done already

[Fiat48]

Ok. Now I remember that deal with the sealing. What I was getting at was how your main bearings were looking in the block you had...which tells me a lot about it's straightness, etc.
Anyway,
You got another block. If your TRW pistons are the comprssion ratio you want (8 to 1 I imagine) and in good shape then reuse them. They are strong enough but just heavy. If not...then SRP seems to be a good choice for quality and strength. If you're going SRP or other aftermarket,then you could do a piston for a .250 long rod which is a nice plus. I do think you should use a heavier type wrist pin. Taper wall 180 grams being the best. TRW pins are not very good and I have broken them. I just throw them away.
Crank wise I just don't like a Chevy crank in a blown application. Especially since you keep mentioning injection is coming, bigger blower is coming, bigger cam etc.
I would do a 4340 Crank for sure. Eagle, Scat, Cola...what have you. Internal balance of the crankshaft has proven easier on the main bearings. These aftermarket cranks are internally balanced already, saving some big bucks for heavy metal. I've probably run 20 Chevy cranks over the years in blown applications but would not even consider it with what is available today. That power you strive to make winds up at the crank and it better be strong. Crank and block flex take out main bearings. The way most blown BBC die.
Rod wise..is rather borderline. A nicely prepared 7/16 dimple rod is a good rod we have run for years. But with the mention of more blower coming, consider a better rod as the other guys mentioned.
I think I would also consider better cylinder heads that flow more air and keep the blower you have (6/71). Then run about 240 lbs on the seat spring pressure, roller cam of around 284/296 @.050 lifting in the 7's.
I always try to build the motor as efficent as I can breathing wise and just add a little bit of blower.
Parts wise consider competition products. CNC motor sports for cranks has had good buys.

[Speedin' Ian]

All good advice Fiat48. Obviously I would love to build a new motor with a dart block, new crank, better heads, etc.... and we will definately do everything we can, but we are working with a budget. You mentioned the bearings in my current motor, but I couldn't remember if you thought they looked good or bad?
With our current heads and pistons the static compression is about 7.2to1 so I think we are going to go with some new pistons, probably SRP. We recently had our heads freshened up and the shop that did them (Sissells Automotive) said they would work fine because they have exstensive porting and polishing, that's not to say a new set of aluminum heads wouldn't be better, I'm sure they would.
I appreciate the advice on the cam, I think we will go with just what you mentioned. With our current cam we can't get the motor to RPM at all, and it sounds very flat.
As for the crank and rods, that is something we will have to seriously think about, obviously with our budget we were hoping to reuse them. The current motor was orignially built over twenty years ago by Norm Grimes (short block has not been apart) and it is internally balanced so the crank and rods have some exstensive work done to them. However if they will fail in the new motor then common sense would tell me to get the right parts now.
One thing to remember with this project is it is going into a lake boat, gets very little use and the owners are working on a budget :D . With the current set-up we ran a 107mph on gps, and we were hoping to hit 120 down the line. I think just freshening up this motor with new pistons and a bigger crank will put us at 115 no problem because we could never get any rpm's out of the old motor. Do we want to switch to injection and a bigger blower? Yes. Will we anytime soon? Maybe the injection but probably not the blower, and if we do step up to a new blower we probably won't bump up the boost, just make them same boost by working the bigger blower less.
As always thanks for the advice and I will probably go with the cam and pistons you mentioned, give serious thought to switching the crank and rods, but I think I will keep the same heads.

[Fiat48]

Was not aware that you had head work done to the 990's. That being the case...keeping them is fine. I think when you up the compression, better camshaft and injection you'll be quite pleased with the performance and easy 120's. Should be no need for a larger blower if that is the speed you are looking for.
I ran 128 with a 468, 8 to 1 trw's, 6/71 blower, injector, and a camshaft like I mentioned in the early 80's. Chevy aluminum heads but they were no better than a set of ported 990's. 7/16 rods and an Ls-7 crank properly prepared. 12 over in the blower, 80A pump and a 125 pill if I remember right. Heavy Cole flat, fact it was Kim Stewarts old fuel flat. No reason you can't do it too. But I think that was about the limit I would want to push with those parts.
PS: That "motor sounds flat" could be a valve spring or simply fuel issue. As in too fat.

[Speedin' Ian]

Sounds like we will be running a very similar set-up to what you had back in the 80's. Our boat is an ex-fuel boat, really flat and heavy. We would be very pleased with those numbers you ran in your old boat. I think we will have to get new valve springs, as the ones in it right know have about 185# seat presure, but that's no big deal. Thanks again for all the advice!

[Fiat48]

Roller cam blown use 240 lbs on seat minimum. Remember seat pressure is negated by boost pressure x sq inches of area of the valve. If that was a roller cam..check your roller lifters carefully. You may have killed them.

[Speedin' Ian]

What do I need to check on them? Last time I had the heads of I took a look at them and they looked, and rolled fine. Also remember I am running a rev kit on this motor so if the springs are too soft the rev kit may have preserved the lifters.

[Fiat48]

Clean the rollers in solvent....rolling them till you make sure all the oil is out of the needles. Then check for any play in the roller. Then roll the rollers very hard against your hand and feel for any roughness or tight spots. Play with them a while..make sure they are tight and smooth. Look at the roller wheel...for any signs of skip marks or cracks. Check and see if the roller pins (depending on brand) are retained by little clips. Are the clips all there? If they are o.k... oil the hell out of them and put them back in.
As for rev kits....not enough spring pressure in a rev kit to help you. Most guys just take rev kits out. Less junk to fail in the valley.

[Fiat48]

Sorry not trying to get you guys off track but Fiat48 can you express your self on the o-ring and recivered head sealing that Speedin'Ian spoke about. I have the same issue. I have been told the Detroit gaskets from Clay Smith will stop my leaking that I had with thick copper gaskets around the water holes?? Plus I am now seeing copper with embosed areas around the water holes...Any comment.
I think his issue if I remember right was 2 0 rings in the block one inside the other. I don't think he has receiver grooves in the heads. Not sure how he finally go it to seal...he'll have to tell you about that.
I have never run anything but coppers on a blown motor. I 0 ring the block myself and I make it so the wire protrudes .020 above the deck. I never receiver groove the heads. For water applications I use Permatex Ultra blue silicone seal. That's the ONLY stuff I use. I seal all the head bolt studs (unless the holes are blind and do not go to water like Dart,Merlin). Then I silicone around all the block water holes and put the gasket on. Then I silcone around all the water holes of the copper gasket. I also silicone around the intake water passages front and rear of the head as those can leak also. Just because your intake gasket has a built in bead of silicone (Fel Pro) around those water passages doesn't mean it will seal. All this siliconing is a pain in the ass.
And I have never had a problem. Maybe 30 or so motors over the years.
Other guys have had big problems and not sure why. Maybe the way it was O ringed. I know some guys are using the Clay Smith and also the Cometic gaskets and that is solving their issues. I do have an unblown 541 to build at 14.1 compression and I will not O ring and I will use the Cometic gaskets.
I think if I were to try to go to these new gaskets and had a block that was O ringed or heads that were receiver grooved, I would file the wire in the block till the surface was flat using a big flat file. Then I would do that also on the head receiver grooves. Then I would put the new gasket on. Not sure that would be absolutely necessary but I would do it.

[Heatseeker]

I was one of those people that couldn't get copper gaskets to seal a couple of seasons back. I lifted the heads five times before I got them to seal up! I followed several people's advice, Fiat's included(Fiat was one of the guys that held my hand all the way through my build, thanks again Bob!). I just couldn't get the fockers to seal! I finally got them to seal up using Yamabond.
And don't forget to do the head studs/bolts like Fiat said. That can be another major source of milkshake frustration!

[Speedin' Ian]

Like Fiat48 mentioned my situation was unique, our block has two sets of o-rings, one inside the other and it was a nightmare trying to get it to seal. I don't know exactly how many times we lifted the heads, but it was over 5 in the span of a few months. Each time it would leak ever so slightly out the frontside of the motor (distributor side) but never leaked into the motor. After we got tired of trying the copper gaskets we tried the Clay smith gaskets and it leaked worst than ever. Eventually we got the copper sealed to the point where there was just a slight drop dripping out of the front of the motor, then we ran this stop leak through it and it hasn't leaked since.

[steelcomp]

Do you guys torque your copper gaskets the same way as the OEM gaskets?? I don't know if this is relevant, but the TF and TA guys that I've been exposed to all torque their heads from the outside-in, not from the center-out, if I remember correctly. Might be for a completely different reason, but I always thought it was the copper gaskets. Of course, these guys don't run water, so sealing for that isn't a problem. Just a thought. :coffeycup

[Fiat48]

Do you guys torque your copper gaskets the same way as the OEM gaskets?? I don't know if this is relevant, but the TF and TA guys that I've been exposed to all torque their heads from the outside-in, not from the center-out, if I remember correctly. Might be for a completely different reason, but I always thought it was the copper gaskets. Of course, these guys don't run water, so sealing for that isn't a problem. Just a thought. :coffeycup
Hemi has the fewest head bolts and much you can get away with for 1320 ft. Circular pattern inside to outside is best.

[steelcomp]

Hemi has the fewest head bolts and much you can get away with for 1320 ft. Circular pattern inside to outside is best.
I agree with you, but these guys can't afford to "get away" with anything. They do it intentionally. I remember being told the other way didn't work for what they were doing...just don't remember why. Like I said, probably mixing apples with copper here. Sorry for the detour. :D :coffeycup

[Speedin' Ian]

Started tearing down the motor looks like we lost a lifter. Also did a leak down and found out we are leaking past the exhaust vlaves pretty bad, pulled one head and there was some rust form condensation so hopefully that is the cause, not to confident though as we are on our secound valve job in a year. So it looks like we will definately be replacing lifters, and may be looking for new heads, we can only hope the rods and crank check out :cry:

[T-Bag]

I always replace my lifters once a year if it needs them or not.. I use triple bond to seal my copper gaskets and have no problems with it. Its sold at most motor cycle shops and is used to seal the case halves on bikes..

[Fiat48]

Started tearing down the motor looks like we lost a lifter. Also did a leak down and found out we are leaking past the exhaust vlaves pretty bad, pulled one head and there was some rust form condensation so hopefully that is the cause, not to confident though as we are on our secound valve job in a year. So it looks like we will definately be replacing lifters, and may be looking for new heads, we can only hope the rods and crank check out :cry:
Broken lifter: Try to find out why. Compare spring pressure..look for broken spring. Check others. They say Morel is the lifter to have now.
2nd valve job in a year: Weak springs beat seats. May be why.
If you do heads or replace valves...be sure to get long valves so you can get that installed height up to at least 2 inches for a better selection of available springs.

[steelcomp]

Broken lifter: Try to find out why. Compare spring pressure..look for broken spring. Check others. They say Morel is the lifter to have now.
2nd valve job in a year: Weak springs beat seats. May be why.
If you do heads or replace valves...be sure to get long valves so you can get that installed height up to at least 2 inches for a better selection of available springs.
It's amazing how many "pro's" never even check their spring pressures. Lot of good power lost there. :coffeycup

[Speedin' Ian]

So here's the deal so far. We are reusing the crank, it had no cracks but does need to be turned, we're reusing the pistons but resizing and repalcing the pins and we will be using our new block with billet mains.
However, even though the rods check out fine we have decided to replace them with Eagle H beams. Heads need to be replaced as well, but I think my head guy has a good set of 990's we can use until we save up money for some nice aluminum heads. Also we are buying a new cam, new lifters, new bearings and new rings.
So here is my question what type of parts should we get as far as the cam, lifters, bearings and rings are concerned? Part #'s would be nice. Fiat48 I know you mentioned what we should be looking for as far as the cam is concerned, but I was hoping you guys could suggest specifics, along with where I should buy it (i.e. competition products).
I know most people are running gapless rings, but my old motor had regular rings and held good presure under a leak down. Can I use standard rings in my new motor?
I know I ask a lot of questions, but this is all greek to me so I want to get as much help and feed back before spending my hard earned money. As always thanks!

[Fiat48]

Are you willing to run 260 lbs on the seat of valve spring pressure?

[Speedin' Ian]

I guess is there any reason why I shouldn't?

[Fiat48]

If you are not going to run the spring pressure required..then there's no sense running a roller cam. Seats get pounded and lifters get beat over not enough spring pressure. Big cams, blown motor, means you have to have that spring pressure. Good springs are $300 a set and up.
But..if the heads are set up with long length valves for tall installed heights....you can run on used springs the Pro stock and other racers sell at the swap meets for $50-$100 a set. Done it for years.

[Speedin' Ian]

I don't think I'll have a problem running the good springs, my buddy does the heads and can usually get me a good deal on springs. What would be the draw back to running a regular cam with solid lifters? What's the advantage of running a roller cam?

[Fiat48]

Basically a roller camshaft let's the cam designer open and close the valve where he would like to...at the ramp speed he would like to...to make the most power. Flat tappets are always a comprimise to keep the lifter alive.