? would too tight of valves cause low compression?

[IQ52]

initially we went with a full turn on the valve adjustments and got lock up, then backed off to 1/4 turn and it seems fine, then one day while checking a compression tester we saw 45-50 lbs of comp?? way low should be up to 110+ right? Seems we thing the valves are still too tight. would backing off to 1/8 of a turn or less work to bring it back up? No other real problems other than crappy eddy 800 and little tweek on the timing.

Ouch, your valves have been hanging open. The XR274HR IS a hydraulic roller cam, they've had you trying to set preload on the 829-16 SOLID ROLLER lifters. You need the 8921-16 hydraulic roller lifters for that cam. .000-.004" preload, or NO MORE than 1/8 turn.

I bet your Edelbrock carburetor will even work better not having to deal with the combustion mixture now swirling around in the intake manifold from the open intake valves.

It's sorta funny......isn't it?

You could, if you wished, run those solid lifters for awhile. Just set the lash, real lash now, at .002-.004" cold gap between the rocker roller and the valve tip. It should open up to .007-.010" gap hot with the aluminum heads. I wouldn't run it for very long, but I'll bet that 493 really wakes up! You could set your timing, with that cam and 493ci, probably 16-18 degrees initial, 36 total, and do your carburetor tuning without hurting the cam. Of course, it's safest to WAIT FOR AND INSTALL the proper lifters.

 

[Meep-Meep]

IQ52 is on to something! If you have solid lifters set at zero lash the engine will start cold then die as it warms up. If you do the preload setting procedure with solid lifters starting from zero lash any amount of turns in will open the valve. Your cam says HYD but you have mechanical lifters according to the box in the pic. Looks like someone messed you up somewhere and you ended up with the wrong lifters. Get the appropriate HYD lifters for that cam and go burn some rubber.

 

[poly3521]

Good catch, Meep-Meep. I didn't see that.

 

[IQ52]

Actually, it will do as I stated, the lash will increase as the engine warms up with the aluminum heads. For instance, with aluminum heads, if you set your cold lash at .025", when the engine gets to operating temperature you will find you have approximately .030" lash. I've tested this time and time again and I know it to be true. The Edelbrock Ford FE heads increase lash about .010"-.012". I have a friend who's fighting that all the time and now he has to build an engine with an aluminum block and the situation is only going to get worse.

 

[IQ52]

Hey, I'm not kidding! There has been some mistake or some extraordinary circumstances if Comp told you to get those 829-16 lifters for your hydraulic cam. Are you positive Comp recommended the solids. I believe you SHOULD NOT run the solid roller lifters long term on your camshaft. Get the 8921-16 hydraulic lifters and install them. There is no correct valve lash for the 829-16 solid roller lifters for your cam. The ramps on the lobes of the XR274HR-10 were not designed for solid rollers. Running a normal solid lifter lash on a hydraulic cam is akin to driving your car over the curb and onto your lawn instead of going up the slope of your driveway. If you do run the solid rollers for a brief period, you have to adjust them with a VERY TIGHT LASH as I have already described.

I've been wrong before, but I stand by what I've said until someone comes up with some different information from Comp Cams.

 

[Cranky]

and no the cam was not ° only #1 to top and marks lined up on timing gear and crank gear. crank gear was installed at mark 4A. it runs fine the only time it back fired on me was when I help it WOT and started it after it died at idle.

Here's the problem with using the dot method. You just don't know if the sprockets are marked right...you just don't know if the cam was ground as it should have been. Also, was the key way in the bottom sprocket broached in the right place? How bout the key way in the crank? Was the alignment pin hole drilled in the cam in the right place? The pin hole in the sprocket? When using a degree wheel to do this job, ALL of those questions go out the window. Production tolerances are seldom perfect and sometimes are so bad that you could have ended up bending all of you intakes or worse. Most times you are close but I've never been able to assemble an engine and be dead on when going by the dots and checking against a wheel. You spend all this hard earned money for the good parts and then cheap out on one of the most important assembly operations in engine building. I've seen it happen way too many times in my 36 years of doing this stuff and I started late in life. Btw, I've even mismatched timing gears go into the box! That happened to a buddy and he bent all of his brand new 2.14 valves. The engine started but his compression was low and it didn't have much power. Bad thing about that job was he owned a degree wheel but got lazy and in a hurry.

Having the cam 4 deg advanced or retarded does not necessarily mean you will have valves hanging open so I wouldn't bother messing with that.

But he has no idea if it's 4 deg either way but like you said being 4* retarded vs 4* advanced shouldn't be a problem except in when the power band comes in....

 

[lewtot184]

Ouch, your valves have been hanging open. The XR274HR IS a hydraulic roller cam, they've had you trying to set preload on the 829-16 SOLID ROLLER lifters. You need the 8921-16 hydraulic roller lifters for that cam. .000-.004" preload, or NO MORE than 1/8 turn.

I bet your Edelbrock carburetor will even work better not having to deal with the combustion mixture now swirling around in the intake manifold from the open intake valves.

It's sorta funny......isn't it?

You could, if you wished, run those solid lifters for awhile. Just set the lash, real lash now, at .002-.004" cold gap between the rocker roller and the valve tip. It should open up to .007-.010" gap hot with the aluminum heads. I wouldn't run it for very long, but I'll bet that 493 really wakes up! You could set your timing, with that cam and 493ci, probably 16-18 degrees initial, 36 total, and do your carburetor tuning without hurting the cam. Of course, it's safest to WAIT FOR AND INSTALL the proper lifters.

if this is the issue; ouch! i'd be wondweing how i got to this. who spec'ed the lifters? as said in later reply, get the correct lifters.

 

[67 B-body]

I'm thinking the pushrod length is going to change as well between solid and Hyd lifters.... You better check it out too when you re-assemble!

 

[67 B-body]

It's probably cheaper to buy a new solid roller cam than new lifters and pushrods....

 

[IQ52]

It's probably cheaper to buy a new solid roller cam than new lifters and pushrods....

Fact! New hydraulic rollers $540 and new solid roller is what? $330? Good push rods $200. If you can get the same base circle on the solid cam you could use the same pushrods. Good idea!

 

[bigmanjbmopar]

Well after pulling my head out of my *** I finally chatted with comp cams and the solid lifters will work fine wit that cam.


The lash settings "HOT" are .008/.010. Cold add .006

Here is the chat script - never mind my bad typing lol


Mick: How may I help you today?
Jack: Hi, I have the 23-710-9 cam and the 829-16 with aluminum heads, the block is a mopar 440 need to know the valve lash setting
Jack: oops 829-16 lifters
Jack: cam card I THINK SAYS .006?
Mick: The 23-710-9 is a hyd. roller camshaft and the card does not give a lash setting at all. If you want to use the 829-16 solid roller lifers on it I would suggest lashing it at .008/.010 for a hot setting
Jack: ok great, is there any compensation setting for cold?
Mick: With aluminum heads I would set them about .006 tighter.
Jack: ok great thanks, last thing the 829-16 lifters will be ok with this cam right? its a street motor we have been running it lightly and no problems except low compressio
Mick: Yes sir they will work fine with that camshaft
Jack: thanks for the help

 

[bigmanjbmopar]

Well all things considered, taking it all apart to swap out the cam and ° the the cam all can be done with the motor still in it. However those hooker super comps don't fit very well in there anyway and I need a shroud for the fan etc.. might as well just tear it down and start over just sux but this has been a huge learning curve for me thank god I have the 383 almost ready as a back up all stock.

Oh and BTW to get the symbol ° just hold the ALT key and type 0176 on the number pad

° ° °

 

[bigmanjbmopar]

comp cam 23-700-9 $324.00 free shipping solid roller

Its funny the comp cams software shows this as a possible set up if you choose solid roller and at the bottom the projected horse power is 574 @5500 and 599 tq @4500 lol vs the hydo cam which comes in at 534 @5500 and 590 @ 4500

wondering if by just switching cams I could pick up that much more power? maybe worth the $270


I also wanted to note that we only checked the number one cyl for compression I have not looked at any of the others yet and even with some mild driving the tires rip loose very easy but does seem to get bogged down after 30 min of normal op temps it idles and drives just wondering how much or how many valves are hung open a bit now maybe just that one...I am at least going to try to dial the lifters with the new lash specs tomorrow.

Unleash the beast!

 

[bigmanjbmopar]

I did confirm with comp cams these lifters will work with this cam......now I am curious as to how much power this combo will actually make? hmmm and how much better the eddy 800 will work like stated lol and yes my timing too has been a challenge.

Hey, I'm not kidding! There has been some mistake or some extraordinary circumstances if Comp told you to get those 829-16 lifters for your hydraulic cam. Are you positive Comp recommended the solids. I believe you SHOULD NOT run the solid roller lifters long term on your camshaft. Get the 8921-16 hydraulic lifters and install them. There is no correct valve lash for the 829-16 solid roller lifters for your cam. The ramps on the lobes of the XR274HR-10 were not designed for solid rollers. Running a normal solid lifter lash on a hydraulic cam is akin to driving your car over the curb and onto your lawn instead of going up the slope of your driveway. If you do run the solid rollers for a brief period, you have to adjust them with a VERY TIGHT LASH as I have already described.

I've been wrong before, but I stand by what I've said until someone comes up with some different information from Comp Cams.

 

[Meep-Meep]

Actually, it will do as I stated, the lash will increase as the engine warms up with the aluminum heads. For instance, with aluminum heads, if you set your cold lash at .025", when the engine gets to operating temperature you will find you have approximately .030" lash. I've tested this time and time again and I know it to be true. The Edelbrock Ford FE heads increase lash about .010"-.012". I have a friend who's fighting that all the time and now he has to build an engine with an aluminum block and the situation is only going to get worse.

Oh yeah, he did say aluminum heads. This is the reason VW used aluminum push rods in the type I, II, II engines. Porsche also went with dilivar head studs to match the expansion of the alloy cylinders but later the stud material was found to be problematic.

Thinking about the push rods on your buddy's FE and wondering if there is a material that is strong enough in compression and can match the CTE of the block and heads. Steel is about half the CTE of aluminum. Hmmm, 1/2" dia 7075 aluminum push rods??? Maybe a hybrid steel/aluminum push rod, where the aluminum part is short and near one end? http://www.engineeringtoolbox.com/linear-expansion-coefficients-d_95.html

 

[IQ52]

Well after pulling my head out of my *** I finally chatted with comp cams and the solid lifters will work fine wit that cam.


The lash settings "HOT" are .008/.010. Cold add .006

Here is the chat script - never mind my bad typing lol


Mick: How may I help you today?
Jack: Hi, I have the 23-710-9 cam and the 829-16 with aluminum heads, the block is a mopar 440 need to know the valve lash setting
Jack: oops 829-16 lifters
Jack: cam card I THINK SAYS .006?
Mick: The 23-710-9 is a hyd. roller camshaft and the card does not give a lash setting at all. If you want to use the 829-16 solid roller lifers on it I would suggest lashing it at .008/.010 for a hot setting
Jack: ok great, is there any compensation setting for cold?
Mick: With aluminum heads I would set them about .006 tighter.
Jack: ok great thanks, last thing the 829-16 lifters will be ok with this cam right? its a street motor we have been running it lightly and no problems except low compressio
Mick: Yes sir they will work fine with that camshaft
Jack: thanks for the help

Good, I'm glad you can run that cam long term with the solid roller lifters.

BUT

Read the transcript of your conversation with Comp Cams carefully. It says .008/.010 hot and with aluminum heads, to go .006" tighter on the cold setting. Therefore the cold setting would be .002/.004".

Tighter doesn't mean add lash, it means subtract lash. If you add .006" for your cold setting, you will set the airgap at .014-.016 cold and when the engine warms up you will have .020-.022 lash. Not good on a hydraulic cam.

Kinda like I was saying from the beginning. .002-.004" cold lash airgap between the roller tip and the valve tip with the solid rollers on the hydraulic cam. When the engine warms up you will have .008-.010. The valve lash gets larger on an aluminum headed engine as the engine warms up. We've all heard it gets smaller, BUT IT DOESN'T. The aluminum head expands and lifts the rocker shafts and rockers away from the cam, increasing the lash.

 

[bigmanjbmopar]

Good catch I will make sure its set cold and hot

Good, I'm glad you can run that cam long term with the solid roller lifters.

BUT

Read the transcript of your conversation with Comp Cams carefully. It says .008/.010 hot and with aluminum heads, to go .006" tighter on the cold setting. Therefore the cold setting would be .002/.004".

Tighter doesn't mean add lash, it means subtract lash. If you add .006" for your cold setting, you will set the airgap at .014-.016 cold and when the engine warms up you will have .020-.022 lash. Not good on a hydraulic cam.

Kinda like I was saying from the beginning. .002-.004" cold lash airgap between the roller tip and the valve tip with the solid rollers on the hydraulic cam. When the engine warms up you will have .008-.010. The valve lash gets larger on an aluminum headed engine as the engine warms up. We've all heard it gets smaller, BUT IT DOESN'T. The aluminum head expands and lifts the rocker shafts and rockers away from the cam, increasing the lash.

 

[bigmanjbmopar]

UPDATE: Well we got them dialed in and HOLY ****!!!!!! LOL what a freaking power band........this has been my problem all along not only with the valve adjustment but guess what? Now I have 15-16 lbs. of vacuum and IT IDLES IN DRIVE!....sorry for the caps but I am so stoked i can't see straight....

This motor has now woken up and the beast is unleashed....going from 1500 to 4500 there is a wicked power band that grabs your face and rips it backwards.

I still need to tweak on the carb since we de-tuned it. but hey all in all I am very pleased.

Now I see why they call solid roller lifters on a hydo cam cheating. lol

 

[Cranky]

Good to hear you got it dialed in!

 

[bigmanjbmopar]

Thanks, my first big block and a stroker at that, so many things to learn so little time well at least so many things to learn.