Should i use new head bolts?

[LarryH]

I'm in the process of rebuilding the engine for my T-Bucket. Should i use new head bolts or are the old ones okay? The bolts look good, no rust at all. I know the engine's been apart at least once because it's .30 over and has early model 350 heads.

It's a mildly built '65 327 that's bored .60 over, align bored, decked, reconditioned rods with new bolts, .194 (76cc) 350 heads, Comp Cams 268H cam, roller tip rockers, gear drive, Edelbrock Performer intake, 600 cfm Performer carb and an HEI. I was just thinking since ARP has them for about $65 they might be cheap insurance.

 

[Lee_in_KC]

...they might be cheap insurance.

I think you answered your own question there, Larry. I always replace any bolt that's been torqued to spec before, especially if I don't know its history. Like you said... cheap insurance.

 

[one finger john]

Larry, saw your inquiry in the HAMB, if the bolts are as you say, then for a mild application or mild street build, you should be fine. Don't lean on them when wire brushing, just enough to clean the threads (use the "whiskers" on the wheel). Use a standard tap (not a .001 or .002 over tap, again you just want to clean the threads, not cut new ones). After everything is cleaned you COULD assign each bolt to a hole and using your fingers, run the bolt down and lightly bottom it (I mean LIGHTLY, just barely) and then get two pieces of card board, mark which bank they belong to, mark top & bottom, front & rear, punch out corresponding holes for the bolts (IIRC, there are two middle length bolts for each head), use a taste of 30 wt. oil to lubricate the threads when installing (can't remember if the bolt holes are blind, use sealer if not) and torque to suit. OR ... just clean everything throughly, oil (or seal), and torque. The bolts should be fine. OR ... you could use ARP bolts, OR you could go with studs.

Decisions, decisions, decisions.

John

P.S. Ask Mike about roller tipped rockers, there is a place to save money.

P.P.S. Don't forget your cam break in additive and after break in, ZDDP additive for every oil change. And don't run Fram oil filters. Delco, Wix, or Catapiller are cool.

 

[ellis8500]

I don't know if it's absolutely true, but I've always read and heard that you should use new head bolts. The reason is, head bolts are torqued to a value that puts a prescribed tension [stretch] on the bolts. This value is not too far, but perfectly ok, from the failure point for the material and size. When you remove a bolt it takes more torque [static torque to break it loose], sometimes lots more, than when it was installed with lube and torque measured while still turning [dynamic torque]. During the removal process the bolt might experience small, internal fractures that you would never see, but could spread, causing bolt failure after it's been installed again. Maybe some of the racing guys could chime in here and tell us what they do on their engines when they replace a head. As for me, I'll always go with new ones. As stated by Lee_In-KC...cheap insurance.

 

[Mike]

Fasteners are cheap. Bin what you have and buy new. ARP is excellent stuff.

 

[fordsbyjay]

I find it funny how for years and years everyone re-used a lot of stock parts (because an alternative was not available) and they worked just fine but now a days nothing is safe and everything needs to be new and you have to have aftermarket blocks and aftermarket fasteners etc. I am not knocking anyone that uses these parts but I see a lot of the same mentality on the other Ford forums I visit. I just don't understand how everything was fine for the last 50 years but now it has to be replaced. I don't know about chevies but I have used factory bolts in all my SBF's except one and in that case I used studs when I swapped on the aluminum heads. For a mild build like yours the the stock head bolts should work IMHO.

 

[RPM]

Clean and chase the threads in the block and wire brush the threads on the bolts and use them over. Don't forget to use some kind of sealer on the threads, or you will have water in the oil. Spend the $65.00 on something else.

Be real careful not to over torque those 11/32" rod bolts! They won't take much.

 

[Northstar T]

I've re-used SBC bolts 1/2 dozen times before with no problems. Many of the new engines coming out do have torque to yeald bolts and some (like my Northstar) have special sealer/antiseize on the threads that can only be used once.
SBC. use en over and buy more beer.

Russ

 

[hotrodman]

Larry, saw your inquiry in the HAMB, if the bolts are as you say, then for a mild application or mild street build, you should be fine. Don't lean on them when wire brushing, just enough to clean the threads (use the "whiskers" on the wheel). Use a standard tap (not a .001 or .002 over tap, again you just want to clean the threads, not cut new ones). After everything is cleaned you COULD assign each bolt to a hole and using your fingers, run the bolt down and lightly bottom it (I mean LIGHTLY, just barely) and then get two pieces of card board, mark which bank they belong to, mark top & bottom, front & rear, punch out corresponding holes for the bolts (IIRC, there are two middle length bolts for each head), use a taste of 30 wt. oil to lubricate the threads when installing (can't remember if the bolt holes are blind, use sealer if not) and torque to suit. OR ... just clean everything throughly, oil (or seal), and torque. The bolts should be fine. OR ... you could use ARP bolts, OR you could go with studs.

Decisions, decisions, decisions.

John

P.S. Ask Mike about roller tipped rockers, there is a place to save money.

P.P.S. Don't forget your cam break in additive and after break in, ZDDP additive for every oil change. FraAm oil filnd don't run ters. Delco, Wix, or Catapiller are cool.

Why don't you like Fram oil filters?

 

[Old Rotor Flap]

Back in the 60's when I started drag racing a blown SBC on fuel, there weren't after market bolts. We used the stock Chevy bolts over and over. Driving over a broken head bolt would have been easier than driving over the those big chunks of hot crankshaft. I'll be re-using the head bolts on my project.... yes Paris, I'm cheap.

 

[Mike]

Why don't you like Fram oil filters?

Cut one apart and you'll see for yourself.

Wix has about half again as much paper as a Fram. Filter are is 193 square inches in a Fram filter. 349 square inches in a Wix. The Wix filter uses lipped, metal end caps at each end of the paper. Fram glues cardboard rings to theirs. Wix uses a spring at the closed end to keep the filter element in place. Fram uses a piece of spring steel.

Fram Filters are the result of an excellent advertising campaign, same as K&N Filters and the old SplitFire Spark Plugs. Snake oil is snake oil is snake oil. Always has been and always will be. Companies like that buy a lot of ads and lead the unsuspecting right into their snares.

Take a look at this site and you can easily see the differences in filter construction.

Which one would you want to run on your motor, now that you've seen the differences?

 

[one finger john]

Thank you Mike, i am a little slow on the draw right now and you responded beautifully. Even though that web site is real close to 10 years old the information it provides is VERY revealing. No automotive magazine would dare print a filter test for fear of losing clients (Fram). It would be nice to see a 2011 test of all the major oil filters. Another site that i like is http://www.bobistheoilguy.com, lots of good info. If we haven't had a real good thread on oil and all things related I think we should. I would especially like to hear from the professional engine builders and their opinions.

John

 

[Mike]

John, it's just like the K&N air filter mystique. Look how that company has grown and all because people don't stop to think.

We used K&N on some of the race motors, as they do a pretty good job of keeping larger birds and beer cans out of the carb. Beyond that, they are absolutely worthless.

Oil is some interesting stuff to play with. The class we raced in comes with penalties for cars that are running too fast against their class index, so we rarely ran the car at its full potential. We always carried some extra ballast and I wouldn't run the trick oils unless it was going to be necessary to win a round. I had oils from three different sources and they all produced different results. The really fast stuff was scary-looking. It didn't look like oil and it certainly didn't pour like oil. That particular oil company provided it to us in white, unmarked bottles. When I asked one of their engineers about what viscosity it was, he explained they didn't grade oils that light by the same standards as regular motor oil, but it would have been something around -10 to -15 if they had.

We ran a Liberty trans in the car (from up around Rick's neighborhood) and after every race, the trans would come apart and get checked for wear/damage. We switched to a synthetic lube and that put an end to trans maintenance. The only time the trans would come apart was to change ratios.

Like I said, it's fun stuff to play with.