To Matt Martin of Centerville Auto Repair- Centerville California

Welcome to V8 Buick Matt, you made a heck of an entrance! LOL!
You make some valid points.... a stock 401/425 is closer to 9.8 out of the factory. It needs to be blueprinted to make the advertised 10.25:1.
Aftermarket pistons suck.... they all result in more deck clearance, lowering compression. Add composite head gaskets and it's even lower. Custom pistons are the way to go (Thanks to Tom T for getting it done!)
401/425 cams are very similar, the better 425 cams had a closer lobe separation..... 109 vs 114 deg for most 401 cams.
The optional 401 for the 66 GS Skylark used the 109 cam and a bigger Q-jet for an additional 15 hp. There was an 11:1 version of that engine avail that the NHRA rated at only 332 hp..... Buick obviously overrated their hp specs.
...
I put a pair of 500 cfm AFB on my 425 way back in 1982. Car ran 13.60's. Put a '66 Q-jet on it and picked up 2 tenths for a best of 13.40 @ 102 mph. The stock air cleaners restrict top end too. Believe that calculates to around 320 hp at the rear wheels.
...
The Nailhead diehards here at V8Buick know their stuff. There are definitely many out there rebuilding their engines that don't have a clue what they are doing.... and ending up with worse-than stock performance.
I've corresponded a bunch with your dad, and learned a lot, from the old Yahoo message boards. Tom T also participated and was a wealth of knowledge.
Stick around, but have some respect for those here that are not idiots (We're not Facebook!), and that includes Jim W who surely knows his stuff when building engines..... but unfortunately hasn't spent much time with the Nailheads (c'mon Jim, show us what you can do!).
Nailheads don't make big hp numbers since they don't rpm well. They do have decent numbers up to 4500 or so, but they won't produce the big numbers like a 7000 SBC will..... but they'll have some great usable STREET power.

Here's hoping you stick around and make some contributions to the board. There's not many Nailheaders out there that know their stuff.

 

It's next to a pot dispensary, LOL!

 

I dont run forged pistons on the majority of the street engines I build. 3 times plus the piston to wall clearance makes for a noiser cold engine and encourages poor ring seal and ring life. Only when turning these engines over 5500 constantly or running forced induction are they necessary. Otherwise theres more cons than pros for most my customers that just want a restoration or a coffee shop car. 500s are too small. Smaller than stock carbs. 30 hp gain by simply switching to 600s and doing nothing else. I have proof of that.. . I was running 750s on a weiand on my wifes 401. Worked really well. I noticed a gain from switching to that from 600s on that perticular build.. But might have been a placebo. Should have results from a similiar build, sooner than later. . No dyno results with doing that though yet, Compared to 600s or 650s. The weiand also isnt as good of an intake as the dual quad edelbrock, eelco, or factory dual quad for the late engines. Yeah the highest compression nailhead without an export kit was the 59 automatic 401. Was rated 10.50 and only ended up being about 9.75. All the 10.25 advertised late engines were around 9.5 to 1. You're right though, they never were designed to make big hp numbers as they were built around moving a heavy car quickly from stop light to stop light with a transmission that didnt shift (dynaflow.)

 

Walt,

My customer had no issue with the 425 I built him.. it was a totally box stock resto, not something we were trying to hot rod, and it did make 460 torque. I knew of the discrepancy between claimed and actual observed HP numbers on nailheads, so I warned him ahead of time.

Measured compression was 9.98-1 and it was completely stock, save for the wider lobe center that I had comp grind into the otherwise duplicate 65 Super Wildcat 091 cam. Wanted to calm it down a little for him at idle, this is a total resto 65 Riv, that is just a cruiser, that will spend some time in parades.

The point of contention here is neither my nor Centerville Auto's ability to build a nailhead. The issue is the ridiculous statement that "you can't dyno a new engine because it is too tight", that Matt's father told my customer.

There is no basis in fact for such a statement, I would suspect that it's what vendors say when they need to make excuses for engines that are dynoed, and don't meet expectations. Otherwise when I posed the question to Matt, he would have come back with something more than "you know they are tight, you have to turn the idle down." I expected a real life experience story of how they built such an such a motor, and it was dynoed right away, and it did not make the power, and so they put it in the car and drove it 500 miles, and then took it out and dynoed it again, and low and behold there is picked up 60 HP... No such story is forthcoming, because no such experience exists.

Anyone who has done the testing on nailheads, will attest to the fact that they made the torque claimed, but never near the HP claimed. Many guys on this board have dynoed nailheads, and been disappointed in the HP output, because they go into thinking "well it made 360 stock, I should have added 40 or 50 HP".. and when all is said and done, their modified engine, does not make it back to the factory rating. A very well respected Twin Cities engine builder was tapped to build a Super Wildcat motor here about a dozen years ago... they really dug into it, ported the heads and had the work verified by a flow bench, upped the compression to a true 11-1, and tried several different profiles of roller cam. I was not a part of this build, but Ron Quarnstrom, a man who spent nearly 30 years dynoing over 10,000 different engines, relayed it to me. The testing was done at his dyno facility. That motor ended up make 560 Torque, but only 370 HP. The engine simply does not have the cross sectional area in the intake tract to flow the cfm required to make high rpm HP in large quantities. Torque is what a nailhead is about.

When I had Cliff Studaker in my office a decade or so ago, I asked him about this directly.. Cliff spent many years as an engineer in Flint, in fact his first job in 1950 was running the dyno.. he smiled when I mentioned the disparity between modern HP numbers for the nailheads, and what was claimed... His response was "as engineers, we battled Olds and Pontiac with torque figures, most of that HP stuff actually came from the sales department."

If you have spent any time around one of Cliff's contemporaries, Dennis Manner, you have heard Denny say that "You buy HP, but you Drive Torque", and with the background above, you can understand the genesis of that thought.

The claims that Russ Martin made, about "should make 360 from the factory" as well as the dyno thing, are exactly what you would expect from someone who is very knowledgeable on the engine family, and on the ins and outs of fits and building, but has very little to no testing experience. And/or gets all his testing input secondhand.

In the last 22 years, I have tested well over 200 Buick engines on the dyno, and until you do the work, one will never understand the value of that testing. I have spent hundreds of hours swapping heads, cams, head gaskets to change compression ratios, intake manifolds, carbs, spacers oil pans and crank scrapers... all done to determine exactly what the changes were worth. To develop combinations that work. All this work has been done with the later BBB, but the point here is unchanged.. you simply don't know, if you don't do the work, and it makes you say silly things like "if you just boost the compression a little and play with the cam, even a 364 will make 400 HP.

That is pure nonsense

------------

Knowledge comes from controlled condition testing.

The factory engineers knew this truth, as well as those of us really trying to build honest, no excuse motors in the aftermarket.. The dyno is where you learn.. and then you take that knowledge to the track and equate it to the actual car. Develop real world combinations that suit the customer's wants or desires.

JW

 

Does it really need more of an explanation than that, that a tight clearance street engine loosens up as time progresses under use, creating less friction and less heat due to friction? Its like asking me what color the sky is. I tell you its blue and you write a 5 paragraph essay telling me I'm wrong because I didnt put the sky on a dyno. Some **** is just common sense. A loose clearance race engine is a different story. I built and ran half a dozen nailheads just for myself in the last decade... without counting hundreds of these engines ive built for customers.

 

There are no downsides to nice modern forged pistons, no piston slap issues.

 

Matt,
Yes, because a "tight clearance" engine does not "wear in". It breaks in the piston rings, which is the major source of friction in a new engine. If everything is right, the main, rod, cam bearing to cam, and piston to wall clearances change very little in a well cared for engine, thru-out the life of that engine.

The phenomenon of "having to turn the idle down" after break in, and extra generated heat, is mainly due to piston ring to cylinder wall beak-in. The rest is due to miscellaneous friction and the friction from a flat tappet cam to the lifters.

I agree, in a brand new engine, until it has run and had some time on it, it will generate extra heat caused by friction. It will require idle speed adjustments after it has run for a while.

What you don't seem to grasp is that we get thru that "break in" period much faster on the dyno.

When we dyno an engine, we run the engine thru 33,000 crank revolutions at 2000rpm to break in the cam, and get all the bearings antiquated with the shafts. After that, the engine is cooled, and then typically 3 WOT pulls is all that is required to break in the rings. Correct cylinder wall finishes for the rings used, assure that.

If your using cast pistons, I assume your stuck with 5/64 rings, but even those with the correct rings and cylinder wall finish break in within 4-5 pulls. You should be using nothing but ductile top rings, with a plasma moly coating. I used ring spacers on that 425, so I could use the same 1/16 compression rings that I use on the 455's, with my custom forged pistons.

The engine is now fully broken in after the first series of "normalization" pulls, and has seen more load than it would in a couple hundred miles of driving.

They are ready to be tested, output now will be well within 1% of what you will see 500 miles from now.

My new street engines do not run hot, nor do they require any large corrections in idle speed, after they are put in use. They are completely broken in after a full dyno session.

--------------------

Start doing the testing, there is no reason not to, I have yet to meet a customer who would not pay for the dyno testing. They want the hard numbers. I understand that Good dyno equipment is expensive, but I would be surprised after all these years if you did not have a local connection to a builder with a dyno, or a dyno shop. I would imagine that in CA, it's probably a lot more expensive to dyno an engine that it is here in MN, but like I said, I am pretty sure most of my customers would have paid twice what I charged them to dyno their new engine. Not only for the numbers, but also for the piece of mind that it is broken in in controlled conditions, it's tuned under load, in both cruise and WOT modes, and all they have to do is hook up the wires and turn the key.

Your shortchanging yourself here, not doing it. Imagine the vast knowledge and hard data you would have, had you tested all those engines over the years.

I don't want to be disagreeable Matt, but I did not start this website to have someone come into my living room, and mislead my friends.... It's my job to make sure that does not happen. I am not saying your a bad guy, don't know you or your dad from Adam, I just think that you have come to believe something, that really is not true.

You need to prove that to yourself, I don't expect you to take my word for it.

JW

 

Right, choose the correct alloy, and piston-wall clearance can be much tighter than the forged pistons of the 60's-70's.
Anyone familiar with Nailheads knows what can happen to a cast piston that's seen lots of detonation or been overrevved!
Custom forged pistons are the only way to get the proper quench and compression ratio without excessive cutting of the deck (or offset grinding the crank).

 

nailhead Matt your killing me. forged pistons stronger, light weight, 8 HP just from thinner rings alone and custom pin height for the right quench. 400 HP on a 364. using a Weiand 2x4 intake. two 750 carbs on a street 401 motor. narrow LSA cam is bad really ?, Buick engineers thought it was good, David Vizard's with all his research thought it was good. even tho i might not count i had a little experience with nailheads, cams, dyno and track time.

 

I know nothing about nailheads. Just want to say as an observer on this entertaining thread I have a little suggestion to Matt. You can have a discussion and disagree with people but you don't have to be a dick about it. Don't be a dick.

If this is your shtick, then don't get all butthurt because someone got offended by it and lashes out. If you are willing to dish it out you better be able to take it otherwise you come across as a tool.

 

I've stayed out of this for various reasons.

Tom T.

 

Right, left, right. Connects with a mean right hook! Its a slober knocker folks!

 

"Member Since: Friday
Nailhead matt was last seen: Monday"


Thank you for those awesome four days!

 

So, let me get this straight. A "guest" comes on here and sucker punches someone who isn't even a member here, hasn't been heard from since said punch, and the sucker punched becomes a member, defends himself, and HE'S the dick??? HE gets ridiculed for not commenting in over 72 hours???

Seems to me the REAL coward and dick owns a '62 'Cat, and is just a guest.

He sounds more like someone who owns a Hemi

 

I believe you have to member to post here. I know he used to be a member for quite a while. I think the reason he shows as "guest" now is because he "terminated" his membership. So when someone brings up an old thread with posts from someone who is no longer a member, it shows that former member as "guest".

 

The whole thread is bizarre.

 

And "Stirs the Pot " .

 

And the plot thickens.

I get giving negative feedback for a subpar experience........but this appears to be an ambush of a non member, who became a member to respond.

Did '62 Cat become a member to solely trash Matt, and then bail???

 

No he was a member here for awhile although he only made rare appearances. What's strange is this forum is for buyer and seller feedback. Neither feedback post from either of these guys was related to a purchase or sale. Simply a way of going after each other for personal issues.