604 Crate Life

[jack.k.harmon]

Which motor would have a longer life span a 604 straight out the crate and into the car or having the motor gone through to get more horsepower and then put into the car. I'm not interested in gaining extra hp out of the motor I just would like to race with the expectations that my motor will last for a long time. Thanks

[zeke23z]

Mine has 4 seasons no rebuilds,3 races oil change,valve springs checked often and change when need be.Never turned more than 6800 rpm.Talkin close to 4500 laps!!

[dynoman14]

If you don't care about the extra power, run the 604 right out of the box. I would make sure I had a good carb with good fuel curve as well as a reliable ignition system. The only think that will kill a 604 is detonation as the pistons are Economy HT material from Mahle. They were designed originally for LT-1 and Performance versions of that engine.

Regular oil changes and good valve springs are a must. I have my customers change springs out every 5 races and I re-treat them for re-use. Have some folks on the same 2 sets of springs for 5000+ laps.

One thing you can gain from re-build is a good round bore and less cylinder wear over time. I see blocks out of tolerance .007" over after a couple seasons of use. I have had rebuilt engines go 4-5 years with hone to re-seal ring pak and still stay within the .007" parameters.

I guess the ones that don't show as much wear are the folks that have figured out how to keep dirt out of their engines and those folks are 1 in 100.

[Egoracing]

One thing you can gain from re-build is a good round bore and less cylinder wear over time.

How are you changing the bore?

[Egoracing]

Ok seeing as there was no reply to my question, The max bore of the GM 604 crate engine is 4.008. If Dyno is making them 4.007 I hope that there is NO cylinder wear or the engine is illegal to race in crate racing. Hope that helps you save some money and the un-needded replacing of the block after part of a season of racing OR winning an event and getting DQ'd because the builder honed the engine to the max and you raced it 1/2 the season.

[Matt49]

Ok seeing as there was no reply to my question, The max bore of the GM 604 crate engine is 4.008. If Dyno is making them 4.007 I hope that there is NO cylinder wear or the engine is illegal to race in crate racing. Hope that helps you save some money and the un-needded replacing of the block after part of a season of racing OR winning an event and getting DQ'd because the builder honed the engine to the max and you raced it 1/2 the season.

I can't wait to see his response

[andy16]

you guys argue like your married and its annoying to see it all the time on here get a life or somethin?????
i thought it was solid advice? and agree with just about all of it.
- if you dont care about hp prob best to just run it out of the box
- you need to have a good carb and ignition so it doesn ever det.
- change the oil and springs often
great advice
i believe he said he has SEEN blocks out of spec .007 AFTER a couple of seasons. didn say he fixed them or honed them out .007 sorry it just doesn say it or mean it?

he said after he hones them they will stay within a .007 over a few rebuilds meaning a proper hone job is important for minimizing bore and piston wear??? thats not hard to understand and i have to agree 100% any good shop can hone a block better than a out of the box gm block thats no secret.

finally he said keep the dirt out

all great advice to help any engine live longer. he answered the mans questions?

[jedclampit]

Run it out of the box ...with clean air/oil/good springs,keep rpms down to get laps up.

Valve seats/sealing take a beating over time, prob the biggest loss in power output in an otherwise sound engine. ...........So as bud 'in the know' informed me.