post me some questions

[JoeinCA]

Hey Grumpy,

I have been having some intake manifold sealing issues. I have a 1988 355, and am using a 302 winters manifold, which i modified to fit the 72 degree center holes, and I am aware that this could be my problem, however i am having difficulty finding a decent square bore manifold that is cast specifically for this application, even the gm performance parts manifold is simply spot faced to 72 degrees. The cylinder heads are PN 10125377.

 

I was hoping to get a gasket reccomendation, Ive tried 2 fel pro versions, and a super thick set of mr.gasket gaskets. All have eventually failed, and I have been anal retentive about going back and keeping the manifold tight to no avail. I believe my next step is to use GM Performance 12497760, or 10159409.

 

Any suggestions would be greatly appreciated.

 

Joe

 

Edit:

Hey Grumpy, TonyD and a few non tech forum guys chimed in on my intake sealing problem. I was advised to try a few things:

First, measure the ports on the manifold and the heads, and make sure to get the appropriate gasket (sensible),

Second, Get "pressure paper" (available at mcmaster carr) and installe in place of the gaskets, and bolt down the manifold lightly to check for warpage/angularity problems with the mating surfaces. Basically to make sure that the "couple thous" the machine shop said the block was decked is really only a couple thous.

And Third, Use good composite gaskets, or double gasket, or double thick gaskets and if necessary rtv the heck out of it to get it to seal. Because the game is to make it work, it doesnt have to be pretty where nobody can see. ( i hate kludging repairs unless absolutely neccessary).

 

Hopefully that will help anyone else out who is having similar trouble.

Edited November 29, 2009 by JoeinCA
additional info and solutions

[78Z/250GTO]

Heres one for you Grumpy: 78Z engine and trans out for sbc conv. w/ Tko 600 waiting in the wings. I am at present dressing out the engine bay and am considering beefing up the frame rails with Zman of washingtons set up. Question--Ideal conditions for this job ..engine/trans out with suspension under load on ramps, no load on jack stands, wait until engine/trans installed,then load or no load.Any advise you could provide would help thanx in advance Jim

[JoeinCA]

78Z

 

Grumpy is the chevy engine guru here. Reading even a little bit would have alerted you to this.

 

I'm not always the brightest crayon in the knife drawer... But if you really are serious about doing extensive automotive restification, you really are going to have to step it up in the information gathering department.

 

look here:

http://forums.hybridz.org/forumdisplay.php?f=61

And here:

http://forums.hybridz.org/forumdisplay.php?s=&daysprune=-1&f=94

 

And finally...:

http://forums.hybridz.org/search.php

 

Brace the hell out of it (tack weld many braces to it before cutting anything out.) engine and trans will get in your way. Ideally, rotisseried for easy welding and metal prep, dont set it on fire, take as much out as you can. If you do not know what you are doing, read write ups from people who have done what you are doing, read as many as you can find, and learn from thier mistakes and successes. In depth fabrication work is not for the feint of heart...

Sorry if I came off as a bit rude, my brain hurts,

 

Joe

[tomcraft]

tomcraft: First get a 1-piece pan gasket NOT made of cork. Use an engine RTV and glue the one-piece gasket to the pan with the RTV and let it cure. Then fill in the four corners of the front and back of the engine pan rail, front cover, and rear cap, with radiused fillets (points of probable leak) of RTV and let in cure. Suspect that there needs to be NO RTV on the top side of the pan gasket as it mates with clean machined surfaces. If the block pan rails, front cover and rear main cap are not clean, do clean them till clean. Hope the rear seal was not the point of the leak! If so this needs to be replace before closing up the engine and pan. With the pan rails clean, front cover groove and rear main cap clean, put the pan back up and tighten the pan bolts. Before putting the pan back on, clean the pan bolt holes and pan bolts very clean with brake cleaning spray fluid. Install the pan and bolt and tighten. Then, with some miles on it after replacing the pan gasket, go back and remove pan bolts one at a time and put on BLUE thread lock and tighten ONE AT A TIME. This will keep it tight and sealed.

thanks for all this useful info im finally going to tackle the problem.I have the full piece thick felpro gasket ,the question is being that the leak wasnt coming from rear or front seal do i cut the gasket and leave the front and rear seals alone[im afraid the gasket being thicker wont allow the cover to tighten enough to the 2 seals].Do i go over them? Do i pull them out and use the new gasket [very afraid to do that].Remember i would have to cut the new gasket because pan only drops 1/2 inch infront to 2 inches in back.I guess another option is leaving the old cork {only ripped in 1 stop] and rtv the engine side.Please what do you think the best option is besides lifting engine .Thanks for your time its very appreciated

[grumpyvette]

thanks for all this useful info im finally going to tackle the problem.I have the full piece thick felpro gasket ,the question is being that the leak wasnt coming from rear or front seal do i cut the gasket and leave the front and rear seals alone[im afraid the gasket being thicker wont allow the cover to tighten enough to the 2 seals].Do i go over them? Do i pull them out and use the new gasket [very afraid to do that].Remember i would have to cut the new gasket because pan only drops 1/2 inch infront to 2 inches in back.I guess another option is leaving the old cork {only ripped in 1 stop] and rtv the engine side.Please what do you think the best option is besides lifting engine .Thanks for your time its very appreciated

 

 

I don,t see why removing the engine to replace the oil pan gasket is not your first option, theres really not much more than at most 3-5 hours work even with just hand tools if youve got an engine crane and engine tilter,and can get a friend to help, during the process to pull, replace and re-install a sbc in a (Z) , with the car up on (4) 12 ton jack stands and air tools and an experienced friend, I bet less than 3 hours from drive in to drive out. but even if it took a full 10-12 hours, doing the job correctly beats patching the oil leak in a slip shod manor, USE the one piece oil pan gasket as the instructions indicate, don,t cut it up

 

http://forum.grumpysperformance.com/viewtopic.php?f=32&t=699&p=972#p972

 

http://forum.grumpysperformance.com/viewtopic.php?f=54&t=206&p=1154&hilit=+synthetic+gasket#p1154

Edited December 7, 2009 by grumpyvette

[tomcraft]

Thats the problem Grumpy I dont have any of the items mentions except hand tools and jack stands .I just want to do the best i can and if it leaks again ill bring it into the shop and get it done correctly.Thanks

[grumpyvette]

I see the PROBLEM as more a LACK of easy access to an engine crane and perhaps a common and understandable reluctance to jump into projects your not familiar with...which once overcome will be to your benefit

 

If your going to be working on cars you EITHER need to join the local car clubs and make contacts where you can borrow one when needed,or

you can BUY an engine crane that will do a decent job, but keep in mind that for about what you can RENT one for over 3-5 days you can BUY an engine crane, so it hardly makes sense to rent one,, Id suggest borrowing or buying one, but you NEED ACCESS TO one to work on cars,

if you look on craigs list , listings or the local bargain trader, news paper,I see them all the time for $80-$100, if you catch one on sale,at HARBOR FREIGHT( just don,t get cheap and buy something thats not safe,) EXAMPLE

these work and go on sale for $148 occasionally

you can always buy a used one off craigs list,( TEST IT WORKS BEFORE YOU PAY FOR IT, BY LIFTING SOMETHING HEAVY) use it and resell it, for little or no true cost,

 

http://www.harborfreight.com/cpi/ctaf/displayitem.taf?Itemnumber=7620

 

If you were local Id suggest you swing by and Id show you how its done in a couple hours, Id be thinking about doing the job correctly and hopefully making the local contacts with car guys that are willing to help you in exchange for you helping them,and that way both guys save cash and gain skills

Edited December 7, 2009 by grumpyvette

[tomcraft]

I see the PROBLEM as more a LACK of easy access to an engine crane and perhaps a common and understandable reluctance to jump into projects your not familiar with...which once overcome will be to your benefit

 

If your going to be working on cars you EITHER need to join the local car clubs and make contacts where you can borrow one when needed,or

you can BUY an engine crane that will do a decent job, but keep in mind that for about what you can RENT one for over 3-5 days you can BUY an engine crane, so it hardly makes sense to rent one,, Id suggest borrowing or buying one, but you NEED ACCESS TO one to work on cars,

if you look on craigs list , listings or the local bargain trader, news paper,I see them all the time for $80-$100, if you catch one on sale,at HARBOR FREIGHT( just don,t get cheap and buy something thats not safe,) EXAMPLE

these work and go on sale for $148 occasionally

you can always buy a used one off craigs list,( TEST IT WORKS BEFORE YOU PAY FOR IT, BY LIFTING SOMETHING HEAVY) use it and resell it, for little or no true cost,

 

http://www.harborfreight.com/cpi/ctaf/displayitem.taf?Itemnumber=7620

 

If you were local Id suggest you swing by and Id show you how its done in a couple hours, Id be thinking about doing the job correctly and hopefully making the local contacts with car guys that are willing to help you in exchange for you helping them,and that way both guys save cash and gain skills

Theres times in peoples lives when time is a luxury not afforded and i need to move the car .I would love nothing more than to do as you suggest but its just not feasable.Thanks anyway ill do my best and hopefully i get some time to do it properly and enjoy myself as well

[rsicard]

Grumpyvette: Just about finished building a SBC 383 stroker. Read one of your posts with pictures of distributors with O'rings on the bottom two lands. Primed the short block to make certain there would be adequate oil pressure. Noticed that oil was bypassing the priming tool and coming up into the valley. Remembered your post and now I will machine a groove, or two, into those lower lands and put O'rings in the grooves to keep the oil going down the oil galley. Trying to think through a method of drilling a small hole inboard of the O'ring on the bottom land or just not machine the bottom land and hope the distributor and cam gear get oil by the leakage between the distributor and block.

 

Need your thoughts and suggestions on how to accomplish pressure oiling of the cam/distributor gears.

[grumpyvette]

if IM reading the post correctly your concerned, that if you just install the upper distributor band groove and O-ring ,to prevent oil escaping into the lifter gallery area, that the lower band without an o-ring, won,t leak enough oil to lube the cam/dist gear contact area

if thats what your worried about , don,t its rarely a problem, but if you want extra oil flow, you can use a jewelers file and cut a shallow groove the the block, adjacent to the lower distributors oil band, above the contact area to provide more high pressure oil spray, just keep is small, as you'll be surprised what even a .005 deep x .010 wide groove will flow

[kirk280zxv8]

As far as gas milage goes i have a gl 83 zx with digital dash and all the bells and whisles but a sbc and turbo 350 trand i finally got the shift points where i want them i guess going from five speed manual to 3 speed no top end. i have 390 gear i think in the rear. i did the calulations tire sizeand rear end gear and 1-1 in trans at 3rd,at 5500rpm 100 that sucks3.36 is that the better gear for the chunk i should have for a better cruising speed on interstate. My friend has a single turbo supra with a th-400 and he can do decent with a 2000 stall and still run10.80@18psi and can go to 30psi.i want less rpm with more top end. Anybody need my rear end or want to swap for different chunk. thanks grumpy for anyhelp i am a bodyman not a normal race car builder, i just make them pretty.

[grumpyvette]

just a question?

why, would you choose to install a th350 with no overdrive when a 700r4 or 2004r would basically give you the top end speed and lower rpms your looking for and still retain the 3.90:1 rear gears off the launch gear advantage

with a 3.90 rear gear ratio and an over drive transmission, a sbc that pulls 6300rpm, and makes 500 plus hp with a 26" tire should in theory, far exceed 160mph, in a 2400lb z

with a 200r4 your able to cruise at about 2600rpm engine speed at 70 mph vs about 3500rpm with a th350 at the same speeds, with the same tires and rear gear ratio.

 

200-4R

2.74

1.57

1.00

0.67

 

700R-4

3.06

1.63

1.00

0.70

 

http://www.thirdgen.org/calculations

 

http://forum.grumpysperformance.com/viewtopic.php?f=71&t=555

Edited December 12, 2009 by grumpyvette

[kirk280zxv8]

Well i sold my zx engine and trans running for 1000.00 and bought sbc and th-350 for the same price so just put it in my car not really knowing. I guess i will sell that trans and get 700r4. thanks for the help

[grumpyvette]

please don,t think I have not made HUNDREDS of mistakes in the last 45 years and done my FULL share of things,that were not well thought thru, but EVENTUALLY I learned to step back and look at ALL the options and my budget and make semi-rational decisions.

I did almost the exact same thing you did back in 1968 with a camaro, and a 454/th400/4.88 rear gear,

quite a few years later I helped install a different transmission with an overdrive installed in the car, and it made a huge difference (even thou by that time the car was owned by a friend)he still drives the car and we both are amazed at how much better the combo is with the od transmission

[MustangSix]

Grump,

 

How about a cam recommendation?

 

350 Chevy, Edelbrock aluminum heads, 9.5:1 CR, C-26 Edelbrock Intake w/ dual 500 Edel carbs (one manual choke, one electric choke). Car is not a Z; it's a 3600lb Jag XJS with a 200-4R and a 2.88 rear riding on 245/45-17 tires.

 

I'm looking for lots of torque, esp down low. The rear mey eventually get swapped, but for now that's the gear I have to live with, so 4th gear will mean low rpms. I'm going to install something that will limit 4th gear engagement until it gets above 40-45 mph. I'll also have a Hobbs switch to disengage the lockup at low vacuum.

 

I've been looking at something pretty mild, but I really want to keep the dual quads for the visual impact, even though a single 4bbl would be easier to do.

 

Any thoughts?

[grumpyvette]

http://www.crower.com/misc/cam_spec/cam_finder.php?part_num=00240&x=39&y=14

 

if I was building that ID use this cam, its a compromise but it should give decent low and mid rpm power and work with the dual quads and 2.88:1 rear gears , provided you can tune the carbs well, Id strongly suggest setting up the linkage so the 4 seperate sets of venturies come in progressively, Id set it up, like described in this thread

 

http://forum.grumpysperformance.com/viewtopic.php?f=55&t=444&p=5682&hilit=quads#p5682

Edited December 18, 2009 by grumpyvette

[bleakdragonmage]

hey grumpy, i have a question. Can oil/trans coolers be too big? I have a 350 with a TH350 auto with 3.90 rear gears in my Z, and i was wondering if it would be ok to use -8AN (1/2" tube) with it, and the cooler i have laying around is pretty big. The trans is upgraded, with a shift kit/full manual valvebody, and i have a high flow oil pump. And i do drive hard on the weekends....

[grumpyvette]

Im using a fairly large TRANS fluid COOLER , and I can,t imagine a 1/2" line being a problem if its correctly plumbed into the system,naturally youll want check valves so it won,t drain and have large volumes of compressed air vs oil at start-up and Id point out that there are thermostatically controlled valves that limit the flow thru the cooler too maintain a minimum oil or trans fluid temperature and up till recently I had a dual oil/trans fluid cooler installed

and youll want to have the OIL cooler set up so all the oil does not route thru the cooler all the time, but only when its over a set temperature.oil coolers are not as simple as a radiator, if correctly installed but they are a huge advantage on transmission and engine durability in some cases

If I had a quality oil/trans fluid cooler with 1/2" lines I would install it without a second thought!

a large capacity baffled oil pan hanging under a car used at higher speeds,will effectively cool oil a good deal more effectively than many people would suspect

 

http://forum.grumpysperformance.com/viewtopic.php?f=57&t=176

Edited December 21, 2009 by grumpyvette

[Rat Fink]

Hey Grumpy, I've seen a lot of tech info on exhaust sizing, but it really comes down to noise vs power. I just don't know how noisy is noisy.

 

Specifically, I have a mild 350 sbc with 2 1/4" dual exhaust.

There's an H pipe, a pair of glasspacks, and two mufflers.

 

In goes the 427 sbc, over 500HP.

 

I think I want 3", but don't know how noisy it's gonna be, like "neighbors calling the cops" noisy? or "cops pull me over for noise ticket" noisy?

I don't know if there's any actual dB information out there, but if there is, you'd know about it.

Exhaust shop says go 2 1/2, they said 3" would actually sound terrible, but...I kind of doubt that.

 

Any other thoughts?

And how do I compare glasspacks? There doesn't seem to be any data, just general claims. Your experience?

Thanks

[grumpyvette]

ok, basics

your noise level will tend to increase with larger diameter exhaust pipes but thats only ONE of MANY factors in the exhaust design and its not necessarily true that you can,t build a reasonably quiet performance exhaust.

glass packs tend to mellow the tone frequency but don,t tend to reduce the DB (noise levels a great deal)

noise is basically vibration strength,thats transmitted to outside the exhaust system. having rubber insulators or exhaust hangers helps,placing glass packs between the (X) pipe and the (H) pipe helps and having quality mufflers helps.

your exhaust noise level is dependent on several factors that you can control,but clearances and finances will effect your choices, basically the idea is to reduce the exhaust pulse strength , you can blend pulses with an (X) as close to the header collectors as clearances allow and placing a secondary (H) pipe before the muffler entrance points tends to further reduce the exhaust pulse strength, but the length of the pipes and muffler design also play a huge role.

everything's going to be a compromise in some area, the object is to maintain a low restriction to flow (low back pressure) system, that effectively allows the headers to scavenge the cylinders, to promote high volumetric efficiency levels with tolerable noise levels

and/or you can insert baffles that will break up the pulse strength,

a set of these in the collectors helps

 

 

read thru these links

 

http://www.pontiacstreetperformance.com/psp/exhaust.html

 

http://www.mustangmonthly.com/techarticles/mump_0812_how_to_install_flow_master_mufflers/index.html

 

http://forum.grumpysperformance.com/viewtopic.php?f=56&t=1507&p=5456#p5456

 

 

http://forum.grumpysperformance.com/viewtopic.php?f=56&t=1507&p=3448&hilit=backpressure#p34

Edited January 15, 2010 by grumpyvette